1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
4005
4006
4007
4008
4009
4010
4011
4012
4013
4014
4015
4016
4017
4018
4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
4035
4036
4037
4038
4039
4040
4041
4042
4043
4044
4045
4046
4047
4048
4049
4050
4051
4052
4053
4054
4055
4056
4057
4058
4059
4060
4061
4062
4063
4064
4065
4066
4067
4068
4069
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108
4109
4110
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
4152
4153
4154
4155
4156
4157
4158
4159
4160
4161
4162
4163
4164
4165
4166
4167
4168
4169
4170
4171
4172
4173
4174
4175
4176
4177
4178
4179
4180
4181
4182
4183
4184
4185
4186
4187
4188
4189
4190
4191
4192
4193
4194
4195
4196
4197
4198
4199
4200
4201
4202
4203
4204
4205
4206
4207
4208
4209
4210
4211
4212
4213
4214
4215
4216
4217
4218
4219
4220
4221
4222
4223
4224
4225
4226
4227
4228
4229
4230
4231
4232
4233
4234
4235
4236
4237
4238
4239
4240
4241
4242
4243
4244
4245
4246
4247
4248
4249
4250
4251
4252
4253
4254
4255
4256
4257
4258
4259
4260
4261
4262
4263
4264
4265
4266
4267
4268
4269
4270
4271
4272
4273
4274
4275
4276
4277
4278
4279
4280
4281
4282
4283
4284
4285
4286
4287
4288
4289
4290
4291
4292
4293
4294
4295
4296
4297
4298
4299
4300
4301
4302
4303
4304
4305
4306
4307
4308
4309
4310
4311
4312
4313
4314
4315
4316
4317
4318
4319
4320
4321
4322
4323
4324
4325
4326
4327
4328
4329
4330
4331
4332
4333
4334
4335
4336
4337
4338
4339
4340
4341
4342
4343
4344
4345
4346
4347
4348
4349
4350
4351
4352
4353
4354
4355
4356
4357
4358
4359
4360
4361
4362
4363
4364
4365
4366
4367
4368
4369
4370
4371
4372
4373
4374
4375
4376
4377
4378
4379
4380
4381
4382
4383
4384
4385
4386
4387
4388
4389
4390
4391
4392
4393
4394
4395
4396
4397
4398
4399
4400
4401
4402
4403
4404
4405
4406
4407
4408
4409
4410
4411
4412
4413
4414
4415
4416
4417
4418
4419
4420
4421
4422
4423
4424
4425
4426
4427
4428
4429
4430
4431
4432
4433
4434
4435
4436
4437
4438
4439
4440
4441
4442
4443
4444
4445
4446
4447
4448
4449
4450
4451
4452
4453
4454
4455
4456
4457
4458
4459
4460
4461
4462
4463
4464
4465
4466
4467
4468
4469
4470
4471
4472
4473
4474
4475
4476
4477
4478
4479
4480
4481
4482
4483
4484
4485
4486
4487
4488
4489
4490
4491
4492
4493
4494
4495
4496
4497
4498
4499
4500
4501
4502
4503
4504
4505
4506
4507
4508
4509
4510
4511
4512
4513
4514
4515
4516
4517
4518
4519
4520
4521
4522
4523
4524
4525
4526
4527
4528
4529
4530
4531
4532
4533
4534
4535
4536
4537
4538
4539
4540
4541
4542
4543
4544
4545
4546
4547
4548
4549
4550
4551
4552
4553
4554
4555
4556
4557
4558
4559
4560
4561
4562
4563
4564
4565
4566
4567
4568
4569
4570
4571
4572
4573
4574
4575
4576
4577
4578
4579
4580
4581
4582
4583
4584
4585
4586
4587
4588
4589
4590
4591
4592
4593
4594
4595
4596
4597
4598
4599
4600
4601
4602
4603
4604
4605
4606
4607
4608
4609
4610
4611
4612
4613
4614
4615
4616
4617
4618
4619
4620
4621
4622
4623
4624
4625
4626
4627
4628
4629
4630
4631
4632
4633
4634
4635
4636
4637
4638
4639
4640
4641
4642
4643
4644
4645
4646
4647
4648
4649
4650
4651
4652
4653
4654
4655
4656
4657
4658
4659
4660
4661
4662
4663
4664
4665
4666
4667
4668
4669
4670
4671
4672
4673
4674
4675
4676
4677
4678
4679
4680
4681
4682
4683
4684
4685
4686
4687
4688
4689
4690
4691
4692
4693
4694
4695
4696
4697
4698
4699
4700
4701
4702
4703
4704
4705
4706
4707
4708
4709
4710
4711
4712
4713
4714
4715
4716
4717
4718
4719
4720
4721
4722
4723
4724
4725
4726
4727
4728
4729
4730
4731
4732
4733
4734
4735
4736
4737
4738
4739
4740
4741
4742
4743
4744
4745
4746
4747
4748
4749
4750
4751
4752
4753
4754
4755
4756
4757
4758
4759
4760
4761
4762
4763
4764
4765
4766
4767
4768
4769
4770
4771
4772
4773
4774
4775
4776
4777
4778
4779
4780
4781
4782
4783
4784
4785
4786
4787
4788
4789
4790
4791
4792
4793
4794
4795
4796
4797
4798
4799
4800
4801
4802
4803
4804
4805
4806
4807
4808
4809
4810
4811
4812
4813
4814
4815
4816
4817
4818
4819
4820
4821
4822
4823
4824
4825
4826
4827
4828
4829
4830
4831
4832
4833
4834
4835
4836
4837
4838
4839
4840
4841
4842
4843
4844
4845
4846
4847
4848
4849
4850
4851
4852
4853
4854
4855
4856
4857
4858
4859
4860
4861
4862
4863
4864
4865
4866
4867
4868
4869
4870
4871
4872
4873
4874
4875
4876
4877
4878
4879
4880
4881
4882
4883
4884
4885
4886
4887
4888
4889
4890
4891
4892
4893
4894
4895
4896
4897
4898
4899
4900
4901
4902
4903
4904
4905
4906
4907
4908
4909
4910
4911
4912
4913
4914
4915
4916
4917
4918
4919
4920
4921
4922
4923
4924
4925
4926
4927
4928
4929
4930
4931
4932
4933
4934
4935
4936
4937
4938
4939
4940
4941
4942
4943
4944
4945
4946
4947
4948
4949
4950
4951
4952
4953
4954
4955
4956
4957
4958
4959
4960
4961
4962
4963
4964
4965
4966
4967
4968
4969
4970
4971
4972
4973
4974
4975
4976
4977
4978
4979
4980
4981
4982
4983
4984
4985
4986
4987
4988
4989
4990
4991
4992
4993
4994
4995
4996
4997
4998
4999
5000
5001
5002
5003
5004
5005
5006
5007
5008
5009
5010
5011
5012
5013
5014
5015
5016
5017
5018
5019
5020
5021
5022
5023
5024
5025
5026
5027
5028
5029
5030
5031
5032
5033
5034
5035
5036
5037
5038
5039
5040
5041
5042
5043
5044
5045
5046
5047
5048
5049
5050
5051
5052
5053
5054
5055
5056
5057
5058
5059
5060
5061
5062
5063
5064
5065
5066
5067
5068
5069
5070
5071
5072
5073
5074
5075
5076
5077
5078
5079
5080
5081
5082
5083
5084
5085
5086
5087
5088
5089
5090
5091
5092
5093
5094
5095
5096
5097
5098
5099
5100
5101
5102
5103
5104
5105
5106
5107
5108
5109
5110
5111
5112
5113
5114
5115
5116
5117
5118
5119
5120
5121
5122
5123
5124
5125
5126
5127
5128
5129
5130
5131
5132
5133
5134
5135
5136
5137
5138
5139
5140
5141
5142
5143
5144
5145
5146
5147
5148
5149
5150
5151
5152
5153
5154
5155
5156
5157
5158
5159
5160
5161
5162
5163
5164
5165
5166
5167
5168
5169
5170
5171
5172
5173
5174
5175
5176
5177
5178
5179
5180
5181
5182
5183
5184
5185
5186
5187
5188
5189
5190
5191
5192
5193
5194
5195
5196
5197
5198
5199
5200
5201
5202
5203
5204
5205
5206
5207
5208
5209
5210
5211
5212
5213
5214
5215
5216
5217
5218
5219
5220
5221
5222
5223
5224
5225
5226
5227
5228
5229
5230
5231
5232
5233
5234
5235
5236
5237
5238
5239
5240
5241
5242
5243
5244
5245
5246
5247
5248
5249
5250
5251
5252
5253
5254
5255
5256
5257
5258
5259
5260
5261
5262
5263
5264
5265
5266
5267
5268
5269
5270
5271
5272
5273
5274
5275
5276
5277
5278
5279
5280
5281
5282
5283
5284
5285
5286
5287
5288
5289
5290
5291
5292
5293
5294
5295
5296
5297
5298
5299
5300
5301
5302
5303
5304
5305
5306
5307
5308
5309
5310
5311
5312
5313
5314
5315
5316
5317
5318
5319
5320
5321
5322
5323
5324
5325
5326
5327
5328
5329
5330
5331
5332
5333
5334
5335
5336
5337
5338
5339
5340
5341
5342
5343
5344
5345
5346
5347
5348
5349
5350
5351
5352
5353
5354
5355
5356
5357
5358
5359
5360
5361
5362
5363
5364
5365
5366
5367
5368
5369
5370
5371
5372
5373
5374
5375
5376
5377
5378
5379
5380
5381
5382
5383
5384
5385
5386
5387
5388
5389
5390
5391
5392
5393
5394
5395
5396
5397
5398
5399
5400
5401
5402
5403
5404
5405
5406
5407
5408
5409
5410
5411
5412
5413
5414
5415
5416
5417
5418
5419
5420
5421
5422
5423
5424
5425
5426
5427
5428
5429
5430
5431
5432
5433
5434
5435
5436
5437
5438
5439
5440
5441
5442
5443
5444
5445
5446
5447
5448
5449
5450
5451
5452
5453
5454
5455
5456
5457
5458
5459
5460
5461
5462
5463
5464
5465
5466
5467
5468
5469
5470
5471
5472
5473
5474
5475
5476
5477
5478
5479
5480
5481
5482
5483
5484
5485
5486
5487
5488
5489
5490
5491
5492
5493
5494
5495
5496
5497
5498
5499
5500
5501
5502
5503
5504
5505
5506
5507
5508
5509
5510
5511
5512
5513
5514
5515
5516
5517
5518
5519
5520
5521
5522
5523
5524
5525
5526
5527
5528
5529
5530
5531
5532
5533
5534
5535
5536
5537
5538
5539
5540
5541
5542
5543
5544
5545
5546
5547
5548
5549
5550
5551
5552
5553
5554
5555
5556
5557
5558
5559
5560
5561
5562
5563
5564
5565
5566
5567
5568
5569
5570
5571
5572
5573
5574
5575
5576
5577
5578
5579
5580
5581
5582
5583
5584
5585
5586
5587
5588
5589
5590
5591
5592
5593
5594
5595
5596
5597
5598
5599
5600
5601
5602
5603
5604
5605
5606
5607
5608
5609
5610
5611
5612
5613
5614
5615
5616
5617
5618
5619
5620
5621
5622
5623
5624
5625
5626
5627
5628
5629
5630
5631
5632
5633
5634
5635
5636
5637
5638
5639
5640
5641
5642
5643
5644
5645
5646
5647
5648
5649
5650
5651
5652
5653
5654
5655
5656
5657
5658
5659
5660
5661
5662
5663
5664
5665
5666
5667
5668
5669
5670
5671
5672
5673
5674
5675
5676
5677
5678
5679
5680
5681
5682
5683
5684
5685
5686
5687
5688
5689
5690
5691
5692
5693
5694
5695
5696
5697
5698
5699
5700
5701
5702
5703
5704
5705
5706
5707
5708
5709
5710
5711
5712
5713
5714
5715
5716
5717
5718
5719
5720
5721
5722
5723
5724
5725
5726
5727
5728
5729
5730
5731
5732
5733
5734
5735
5736
5737
5738
5739
5740
5741
5742
5743
5744
5745
5746
5747
5748
5749
5750
5751
5752
5753
5754
5755
5756
5757
5758
5759
5760
5761
5762
5763
5764
5765
5766
5767
5768
5769
5770
5771
5772
5773
5774
5775
5776
5777
5778
5779
5780
5781
5782
5783
5784
5785
5786
5787
5788
5789
5790
5791
5792
5793
5794
5795
5796
5797
5798
5799
5800
5801
5802
5803
5804
5805
5806
5807
5808
5809
5810
5811
5812
5813
5814
5815
5816
5817
5818
5819
5820
5821
5822
5823
5824
5825
5826
5827
5828
5829
5830
5831
5832
5833
5834
5835
5836
5837
5838
5839
5840
5841
5842
5843
5844
5845
5846
5847
5848
5849
5850
5851
5852
5853
5854
5855
5856
5857
5858
5859
5860
5861
5862
5863
5864
5865
5866
5867
5868
5869
5870
5871
5872
5873
5874
5875
5876
5877
5878
5879
5880
5881
5882
5883
5884
5885
5886
5887
5888
5889
5890
5891
5892
5893
5894
5895
5896
5897
5898
5899
5900
5901
5902
5903
5904
5905
5906
5907
5908
5909
5910
5911
5912
5913
5914
5915
5916
5917
5918
5919
5920
5921
5922
5923
5924
5925
5926
5927
5928
5929
5930
5931
5932
5933
5934
5935
5936
5937
5938
5939
5940
5941
5942
5943
5944
5945
5946
5947
5948
5949
5950
5951
5952
5953
5954
5955
5956
5957
5958
5959
5960
5961
5962
5963
5964
5965
5966
5967
5968
5969
5970
5971
5972
5973
5974
5975
5976
5977
5978
5979
5980
5981
5982
5983
5984
5985
5986
5987
5988
5989
5990
5991
5992
5993
5994
5995
5996
5997
5998
5999
6000
6001
6002
6003
6004
6005
6006
6007
6008
6009
6010
6011
6012
6013
6014
6015
6016
6017
6018
6019
6020
6021
6022
6023
6024
6025
6026
6027
6028
6029
6030
6031
6032
6033
6034
6035
6036
6037
6038
6039
6040
6041
6042
6043
6044
6045
6046
6047
6048
6049
6050
6051
6052
6053
6054
6055
6056
6057
6058
6059
6060
6061
6062
6063
6064
6065
6066
6067
6068
6069
6070
6071
6072
6073
6074
6075
6076
6077
6078
6079
6080
6081
6082
6083
6084
6085
6086
6087
6088
6089
6090
6091
6092
6093
6094
6095
6096
6097
6098
6099
6100
6101
6102
6103
6104
6105
6106
6107
6108
6109
6110
6111
6112
6113
6114
6115
6116
6117
6118
6119
6120
6121
6122
6123
6124
6125
6126
6127
6128
6129
6130
6131
6132
6133
6134
6135
6136
6137
6138
6139
6140
6141
6142
6143
6144
6145
6146
6147
6148
6149
6150
6151
6152
6153
6154
6155
6156
6157
6158
6159
6160
6161
6162
6163
6164
6165
6166
6167
6168
6169
6170
6171
6172
6173
6174
6175
6176
6177
6178
6179
6180
6181
6182
6183
6184
6185
6186
6187
6188
6189
6190
6191
6192
6193
6194
6195
6196
6197
6198
6199
6200
6201
6202
6203
6204
6205
6206
6207
6208
6209
6210
6211
6212
6213
6214
6215
6216
6217
6218
6219
6220
6221
6222
6223
6224
6225
6226
6227
6228
6229
6230
6231
6232
6233
6234
6235
6236
6237
6238
6239
6240
6241
6242
6243
6244
6245
6246
6247
6248
6249
6250
6251
6252
6253
6254
6255
6256
6257
6258
6259
6260
6261
6262
6263
6264
6265
6266
6267
6268
6269
6270
6271
6272
6273
6274
6275
6276
6277
6278
6279
6280
6281
6282
6283
6284
6285
6286
6287
6288
6289
6290
6291
6292
6293
6294
6295
6296
6297
6298
6299
6300
6301
6302
6303
6304
6305
6306
6307
6308
6309
6310
6311
6312
6313
6314
6315
6316
6317
6318
6319
6320
6321
6322
6323
6324
6325
6326
6327
6328
6329
6330
6331
6332
6333
6334
6335
6336
6337
6338
6339
6340
6341
6342
6343
6344
6345
6346
6347
6348
6349
6350
6351
6352
6353
6354
6355
6356
6357
6358
6359
6360
6361
6362
6363
6364
6365
6366
6367
6368
6369
6370
6371
6372
6373
6374
6375
6376
6377
6378
6379
6380
6381
6382
6383
6384
6385
6386
6387
6388
6389
6390
6391
6392
6393
6394
6395
6396
6397
6398
6399
6400
6401
6402
6403
6404
6405
6406
6407
6408
6409
6410
6411
6412
6413
6414
6415
6416
6417
6418
6419
6420
6421
6422
6423
6424
6425
6426
6427
6428
6429
6430
6431
6432
6433
6434
6435
6436
6437
6438
6439
6440
6441
6442
6443
6444
6445
6446
6447
6448
6449
6450
6451
6452
6453
6454
6455
6456
6457
6458
6459
6460
6461
6462
6463
6464
6465
6466
6467
6468
6469
6470
6471
6472
6473
6474
6475
6476
6477
6478
6479
6480
6481
6482
6483
6484
6485
6486
6487
6488
6489
6490
6491
6492
6493
6494
6495
6496
6497
6498
6499
6500
6501
6502
6503
6504
6505
6506
6507
6508
6509
6510
6511
6512
6513
6514
6515
6516
6517
6518
6519
6520
6521
6522
6523
6524
6525
6526
6527
6528
6529
6530
6531
6532
6533
6534
6535
6536
6537
6538
6539
6540
6541
6542
6543
6544
6545
6546
6547
6548
6549
6550
6551
6552
6553
6554
6555
6556
6557
6558
6559
6560
6561
6562
6563
6564
6565
6566
6567
6568
6569
6570
6571
6572
6573
6574
6575
6576
6577
6578
6579
6580
6581
6582
6583
6584
6585
6586
6587
6588
6589
6590
6591
6592
6593
6594
6595
6596
6597
6598
6599
6600
6601
6602
6603
6604
6605
6606
6607
6608
6609
6610
6611
6612
6613
6614
6615
6616
6617
6618
6619
6620
6621
6622
6623
6624
6625
6626
6627
6628
6629
6630
6631
6632
6633
6634
6635
6636
6637
6638
6639
6640
6641
6642
6643
6644
6645
6646
6647
6648
6649
6650
6651
6652
6653
6654
6655
6656
6657
6658
6659
6660
6661
6662
6663
6664
6665
6666
6667
6668
6669
6670
6671
6672
6673
6674
6675
6676
6677
6678
6679
6680
6681
6682
6683
6684
6685
6686
6687
6688
6689
6690
6691
6692
6693
6694
6695
6696
6697
6698
6699
6700
6701
6702
6703
6704
6705
6706
6707
6708
6709
6710
6711
6712
6713
6714
6715
6716
6717
6718
6719
6720
6721
6722
6723
6724
6725
6726
6727
6728
6729
6730
6731
6732
6733
6734
6735
6736
6737
6738
6739
6740
6741
6742
6743
6744
6745
6746
6747
6748
6749
6750
6751
6752
6753
6754
6755
6756
6757
6758
6759
6760
6761
6762
6763
6764
6765
6766
6767
6768
6769
6770
6771
6772
6773
6774
6775
6776
6777
6778
6779
6780
6781
6782
6783
6784
6785
6786
6787
6788
6789
6790
6791
6792
6793
6794
6795
6796
6797
6798
6799
6800
6801
6802
6803
6804
6805
6806
6807
6808
6809
6810
6811
6812
6813
6814
6815
6816
6817
6818
6819
6820
6821
6822
6823
6824
6825
6826
6827
6828
6829
6830
6831
6832
6833
6834
6835
6836
6837
6838
6839
6840
6841
6842
6843
6844
6845
6846
6847
6848
6849
6850
6851
6852
6853
6854
6855
6856
6857
6858
6859
6860
6861
6862
6863
6864
6865
6866
6867
6868
6869
6870
6871
6872
6873
6874
6875
6876
6877
6878
6879
6880
6881
6882
6883
6884
6885
6886
6887
6888
6889
6890
6891
6892
6893
6894
6895
6896
6897
6898
6899
6900
6901
6902
6903
6904
6905
6906
6907
6908
6909
6910
6911
6912
6913
6914
6915
6916
6917
6918
6919
6920
6921
6922
6923
6924
6925
6926
6927
6928
6929
6930
6931
6932
6933
6934
6935
6936
6937
6938
6939
6940
6941
6942
6943
6944
6945
6946
6947
6948
6949
6950
6951
6952
6953
6954
6955
6956
6957
6958
6959
6960
6961
6962
6963
6964
6965
6966
6967
6968
6969
6970
6971
6972
6973
6974
6975
6976
6977
6978
6979
6980
6981
6982
6983
6984
6985
6986
6987
6988
6989
6990
6991
6992
6993
6994
6995
6996
6997
6998
6999
7000
7001
7002
7003
7004
7005
7006
7007
7008
7009
7010
7011
7012
7013
7014
7015
7016
7017
7018
7019
7020
7021
7022
7023
7024
7025
7026
7027
7028
7029
7030
7031
7032
7033
7034
7035
7036
7037
7038
7039
7040
7041
7042
7043
7044
7045
7046
7047
7048
7049
7050
7051
7052
7053
7054
7055
7056
7057
7058
7059
7060
7061
7062
7063
7064
7065
7066
7067
7068
7069
7070
7071
7072
7073
7074
7075
7076
7077
7078
7079
7080
7081
7082
7083
7084
7085
7086
7087
7088
7089
7090
7091
7092
7093
7094
7095
7096
7097
7098
7099
7100
7101
7102
7103
7104
7105
7106
7107
7108
7109
7110
7111
7112
7113
7114
7115
7116
7117
7118
7119
7120
7121
7122
7123
7124
7125
7126
7127
7128
7129
7130
7131
7132
7133
7134
7135
7136
7137
7138
7139
7140
7141
7142
7143
7144
7145
7146
7147
7148
7149
7150
7151
7152
7153
7154
7155
7156
7157
7158
7159
7160
7161
7162
7163
7164
7165
7166
7167
7168
7169
7170
7171
7172
7173
7174
7175
7176
7177
7178
7179
7180
7181
7182
7183
7184
7185
7186
7187
7188
7189
7190
7191
7192
7193
7194
7195
7196
7197
7198
7199
7200
7201
7202
7203
7204
7205
7206
7207
7208
7209
7210
7211
7212
7213
7214
7215
7216
7217
7218
7219
7220
7221
7222
7223
7224
7225
7226
7227
7228
7229
7230
7231
7232
7233
7234
7235
7236
7237
7238
7239
7240
7241
7242
7243
7244
7245
7246
7247
7248
7249
7250
7251
7252
7253
7254
7255
7256
7257
7258
7259
7260
7261
7262
7263
7264
7265
7266
7267
7268
7269
7270
7271
7272
7273
7274
7275
7276
7277
7278
7279
7280
7281
7282
7283
7284
7285
7286
7287
7288
7289
7290
7291
7292
7293
7294
7295
7296
7297
7298
7299
7300
7301
7302
7303
7304
7305
7306
7307
7308
7309
7310
7311
7312
7313
7314
7315
7316
7317
7318
7319
7320
7321
7322
7323
7324
7325
7326
7327
7328
7329
7330
7331
7332
7333
7334
7335
7336
7337
7338
7339
7340
7341
7342
7343
7344
7345
7346
7347
7348
7349
7350
7351
7352
7353
7354
7355
7356
7357
7358
7359
7360
7361
7362
7363
7364
7365
7366
7367
7368
7369
7370
7371
7372
7373
7374
7375
7376
7377
7378
7379
7380
7381
7382
7383
7384
7385
7386
7387
7388
7389
7390
7391
7392
7393
7394
7395
7396
7397
7398
7399
7400
7401
7402
7403
7404
7405
7406
7407
7408
7409
7410
7411
7412
7413
7414
7415
7416
7417
7418
7419
7420
7421
7422
7423
7424
7425
7426
7427
7428
7429
7430
7431
7432
7433
7434
7435
7436
7437
7438
7439
7440
7441
7442
7443
7444
7445
7446
7447
7448
7449
7450
7451
7452
7453
7454
7455
7456
7457
7458
7459
7460
7461
7462
7463
7464
7465
7466
7467
7468
7469
7470
7471
7472
7473
7474
7475
7476
7477
7478
7479
7480
7481
7482
7483
7484
7485
7486
7487
7488
7489
7490
7491
7492
7493
7494
7495
7496
7497
7498
7499
7500
7501
7502
7503
7504
7505
7506
7507
7508
7509
7510
7511
7512
7513
7514
7515
7516
7517
7518
7519
7520
7521
7522
7523
7524
7525
7526
7527
7528
7529
7530
7531
7532
7533
7534
7535
7536
7537
7538
7539
7540
7541
7542
7543
7544
7545
7546
7547
7548
7549
7550
7551
7552
7553
7554
7555
7556
7557
7558
7559
7560
7561
7562
7563
7564
7565
7566
7567
7568
7569
7570
7571
7572
7573
7574
7575
7576
7577
7578
7579
7580
7581
7582
7583
7584
7585
7586
7587
7588
7589
7590
7591
7592
7593
7594
7595
7596
7597
7598
7599
7600
7601
7602
7603
7604
7605
7606
7607
7608
7609
7610
7611
7612
7613
7614
7615
7616
7617
7618
7619
7620
7621
7622
7623
7624
7625
7626
7627
7628
7629
7630
7631
7632
7633
7634
7635
7636
7637
7638
7639
7640
7641
7642
7643
7644
7645
7646
7647
7648
7649
7650
7651
7652
7653
7654
7655
7656
7657
7658
7659
7660
7661
7662
7663
7664
7665
7666
7667
7668
7669
7670
7671
7672
7673
7674
7675
7676
7677
7678
7679
7680
7681
7682
7683
7684
7685
7686
7687
7688
7689
7690
7691
7692
7693
7694
7695
7696
7697
7698
7699
7700
7701
7702
7703
7704
7705
7706
7707
7708
7709
7710
7711
7712
7713
7714
7715
7716
7717
7718
7719
7720
7721
7722
7723
7724
7725
7726
7727
7728
7729
7730
7731
7732
7733
7734
7735
7736
7737
7738
7739
7740
7741
7742
7743
7744
7745
7746
7747
7748
7749
7750
7751
7752
7753
7754
7755
7756
7757
7758
7759
7760
7761
7762
7763
7764
7765
7766
7767
7768
7769
7770
7771
7772
7773
7774
7775
7776
7777
7778
7779
7780
7781
7782
7783
7784
7785
7786
7787
7788
7789
7790
7791
7792
7793
7794
7795
7796
7797
7798
7799
7800
7801
7802
7803
7804
7805
7806
7807
7808
7809
7810
7811
7812
7813
7814
7815
7816
7817
7818
7819
7820
7821
7822
7823
7824
7825
7826
7827
7828
7829
7830
7831
7832
7833
7834
7835
7836
7837
7838
7839
7840
7841
7842
7843
7844
7845
7846
7847
7848
7849
7850
7851
7852
7853
7854
7855
7856
7857
7858
7859
7860
7861
7862
7863
7864
7865
7866
7867
7868
7869
7870
7871
7872
7873
7874
7875
7876
7877
7878
7879
7880
7881
7882
7883
7884
7885
7886
7887
7888
7889
7890
7891
7892
7893
7894
7895
7896
7897
7898
7899
7900
7901
7902
7903
7904
7905
7906
7907
7908
7909
7910
7911
7912
7913
7914
7915
7916
7917
7918
7919
7920
7921
7922
7923
7924
7925
7926
7927
7928
7929
7930
7931
7932
7933
7934
7935
7936
7937
7938
7939
7940
7941
7942
7943
7944
7945
7946
7947
7948
7949
7950
7951
7952
7953
7954
7955
7956
7957
7958
7959
7960
7961
7962
7963
7964
7965
7966
7967
7968
7969
7970
7971
7972
7973
7974
7975
7976
7977
7978
7979
7980
7981
7982
7983
7984
7985
7986
7987
7988
7989
7990
7991
7992
7993
7994
7995
7996
7997
7998
7999
8000
8001
8002
8003
8004
8005
8006
8007
8008
8009
8010
8011
8012
8013
8014
8015
8016
8017
8018
8019
8020
8021
8022
8023
8024
8025
8026
8027
8028
8029
8030
8031
8032
8033
8034
8035
8036
8037
8038
8039
8040
8041
8042
8043
8044
8045
8046
8047
8048
8049
8050
8051
8052
8053
8054
8055
8056
8057
8058
8059
8060
8061
8062
8063
8064
8065
8066
8067
8068
8069
8070
8071
8072
8073
8074
8075
8076
8077
8078
8079
8080
8081
8082
8083
8084
8085
8086
8087
8088
8089
8090
8091
8092
8093
8094
8095
8096
8097
8098
8099
8100
8101
8102
8103
8104
8105
8106
8107
8108
8109
8110
8111
8112
8113
8114
8115
8116
8117
8118
8119
8120
8121
8122
8123
8124
8125
8126
8127
8128
8129
8130
8131
8132
8133
8134
8135
8136
8137
8138
8139
8140
8141
8142
8143
8144
8145
8146
8147
8148
8149
8150
8151
8152
8153
8154
8155
8156
8157
8158
8159
8160
8161
8162
8163
8164
8165
8166
8167
8168
8169
8170
8171
8172
8173
8174
8175
8176
8177
8178
8179
8180
8181
8182
8183
8184
8185
8186
8187
8188
8189
8190
8191
8192
8193
8194
8195
8196
8197
8198
8199
8200
8201
8202
8203
8204
8205
8206
8207
8208
8209
8210
8211
8212
8213
8214
8215
8216
8217
8218
8219
8220
8221
8222
8223
8224
8225
8226
8227
8228
8229
8230
8231
8232
8233
8234
8235
8236
8237
8238
8239
8240
8241
8242
8243
8244
8245
8246
8247
8248
8249
8250
8251
8252
8253
8254
8255
8256
8257
8258
8259
8260
8261
8262
8263
8264
8265
8266
8267
8268
8269
8270
8271
8272
8273
8274
8275
8276
8277
8278
8279
8280
8281
8282
8283
8284
8285
8286
8287
8288
8289
8290
8291
8292
8293
8294
8295
8296
8297
8298
8299
8300
8301
8302
8303
8304
8305
8306
8307
8308
8309
8310
8311
8312
8313
8314
8315
8316
8317
8318
8319
8320
8321
8322
8323
8324
8325
8326
8327
8328
8329
8330
8331
8332
8333
8334
8335
8336
8337
8338
8339
8340
8341
8342
8343
8344
8345
8346
8347
8348
8349
8350
8351
8352
8353
8354
8355
8356
8357
8358
8359
8360
8361
8362
8363
8364
8365
8366
8367
8368
8369
8370
8371
8372
8373
8374
8375
8376
8377
8378
8379
8380
8381
8382
8383
8384
8385
8386
8387
8388
8389
8390
8391
8392
8393
8394
8395
8396
8397
8398
8399
8400
8401
8402
8403
8404
8405
8406
8407
8408
8409
8410
8411
8412
8413
8414
8415
8416
8417
8418
8419
8420
8421
8422
8423
8424
8425
8426
8427
8428
8429
8430
8431
8432
8433
8434
8435
8436
8437
8438
8439
8440
8441
8442
8443
8444
8445
8446
8447
8448
8449
8450
8451
8452
8453
8454
8455
8456
8457
8458
8459
8460
8461
8462
8463
8464
8465
8466
8467
8468
8469
8470
8471
8472
8473
8474
8475
8476
8477
8478
8479
8480
8481
8482
8483
8484
8485
8486
8487
8488
8489
8490
8491
8492
8493
8494
8495
8496
8497
8498
8499
8500
8501
8502
8503
8504
8505
8506
8507
8508
8509
8510
8511
8512
8513
8514
8515
8516
8517
8518
8519
8520
8521
8522
8523
8524
8525
8526
8527
8528
8529
8530
8531
8532
8533
8534
8535
8536
8537
8538
8539
8540
8541
8542
8543
8544
8545
8546
8547
8548
8549
8550
8551
8552
8553
8554
8555
8556
8557
8558
8559
8560
8561
8562
8563
8564
8565
8566
8567
8568
8569
8570
8571
8572
8573
8574
8575
8576
8577
8578
8579
8580
8581
8582
8583
8584
8585
8586
8587
8588
8589
8590
8591
8592
8593
8594
8595
8596
8597
8598
8599
8600
8601
8602
8603
8604
8605
8606
8607
8608
8609
8610
8611
8612
8613
8614
8615
8616
8617
8618
8619
8620
8621
8622
8623
8624
8625
8626
8627
8628
8629
8630
8631
8632
8633
8634
8635
8636
8637
8638
8639
8640
8641
8642
8643
8644
8645
8646
8647
8648
8649
8650
8651
8652
8653
8654
8655
8656
8657
8658
8659
8660
8661
8662
8663
8664
8665
8666
8667
8668
8669
8670
8671
8672
8673
8674
8675
8676
8677
8678
8679
8680
8681
8682
8683
8684
8685
8686
8687
8688
8689
8690
8691
8692
8693
8694
8695
8696
8697
8698
8699
8700
8701
8702
8703
8704
8705
8706
8707
8708
8709
8710
8711
8712
8713
8714
8715
8716
8717
8718
8719
8720
8721
8722
8723
8724
8725
8726
8727
8728
8729
8730
8731
8732
8733
8734
8735
8736
8737
8738
8739
8740
8741
8742
8743
8744
8745
8746
8747
8748
8749
8750
8751
8752
8753
8754
8755
8756
8757
8758
8759
8760
8761
8762
8763
8764
8765
8766
8767
8768
8769
8770
8771
8772
8773
8774
8775
8776
8777
8778
8779
8780
8781
8782
8783
8784
8785
8786
8787
8788
8789
8790
8791
8792
8793
8794
8795
8796
8797
8798
8799
8800
8801
8802
8803
8804
8805
8806
8807
8808
8809
8810
8811
8812
8813
8814
8815
8816
8817
8818
8819
8820
8821
8822
8823
8824
8825
8826
8827
8828
8829
8830
8831
8832
8833
8834
8835
8836
8837
8838
8839
8840
8841
8842
8843
8844
8845
8846
8847
8848
8849
8850
8851
8852
8853
8854
8855
8856
8857
8858
8859
8860
8861
8862
8863
8864
8865
8866
8867
8868
8869
8870
8871
8872
8873
8874
8875
8876
8877
8878
8879
8880
8881
8882
8883
8884
8885
8886
8887
8888
8889
8890
8891
8892
8893
8894
8895
8896
8897
8898
8899
8900
8901
8902
8903
8904
8905
8906
8907
8908
8909
8910
8911
8912
8913
8914
8915
8916
8917
8918
8919
8920
8921
8922
8923
8924
8925
8926
8927
8928
8929
8930
8931
8932
8933
8934
8935
8936
8937
8938
8939
8940
8941
8942
8943
8944
8945
8946
8947
8948
8949
8950
8951
8952
8953
8954
8955
8956
8957
8958
8959
8960
8961
8962
8963
8964
8965
8966
8967
8968
8969
8970
8971
8972
8973
8974
8975
8976
8977
8978
8979
8980
8981
8982
8983
8984
8985
8986
8987
8988
8989
8990
8991
8992
8993
8994
8995
8996
8997
8998
8999
9000
9001
9002
9003
9004
9005
9006
9007
9008
9009
9010
9011
9012
9013
9014
9015
9016
9017
9018
9019
9020
9021
9022
9023
9024
9025
9026
9027
9028
9029
9030
9031
9032
9033
9034
9035
9036
9037
9038
9039
9040
9041
9042
9043
9044
9045
9046
9047
9048
9049
9050
9051
9052
9053
9054
9055
9056
9057
9058
9059
9060
9061
9062
9063
9064
9065
9066
9067
9068
9069
9070
9071
9072
9073
9074
9075
9076
9077
9078
9079
9080
9081
9082
9083
9084
9085
9086
9087
9088
9089
9090
9091
9092
9093
9094
9095
9096
9097
9098
9099
9100
9101
9102
9103
9104
9105
9106
9107
9108
9109
9110
9111
9112
9113
9114
9115
9116
9117
9118
9119
9120
9121
9122
9123
9124
9125
9126
9127
9128
9129
9130
9131
9132
9133
9134
9135
9136
9137
9138
9139
9140
9141
9142
9143
9144
9145
9146
9147
9148
9149
9150
9151
9152
9153
9154
9155
9156
9157
9158
9159
9160
9161
9162
9163
9164
9165
9166
9167
9168
9169
9170
9171
9172
9173
9174
9175
9176
9177
9178
9179
9180
9181
9182
9183
9184
9185
9186
9187
9188
9189
9190
9191
9192
9193
9194
9195
9196
9197
9198
9199
9200
9201
9202
9203
9204
9205
9206
9207
9208
9209
9210
9211
9212
9213
9214
9215
9216
9217
9218
9219
9220
9221
9222
9223
9224
9225
9226
9227
9228
9229
9230
9231
9232
9233
9234
9235
9236
9237
9238
9239
9240
9241
9242
9243
9244
9245
9246
9247
9248
9249
9250
9251
9252
9253
9254
9255
9256
9257
9258
9259
9260
9261
9262
9263
9264
9265
9266
9267
9268
9269
9270
9271
9272
9273
9274
9275
9276
9277
9278
9279
9280
9281
9282
9283
9284
9285
9286
9287
9288
9289
9290
9291
9292
9293
9294
9295
9296
9297
9298
9299
9300
9301
9302
9303
9304
9305
9306
9307
9308
9309
9310
9311
9312
9313
9314
9315
9316
9317
9318
9319
9320
9321
9322
9323
9324
9325
9326
9327
9328
9329
9330
9331
9332
9333
9334
9335
9336
9337
9338
9339
9340
9341
9342
9343
9344
9345
9346
9347
9348
9349
9350
9351
9352
9353
9354
9355
9356
9357
9358
9359
9360
9361
9362
9363
9364
9365
9366
9367
9368
9369
9370
9371
9372
9373
9374
9375
9376
9377
9378
9379
9380
9381
9382
9383
9384
9385
9386
9387
9388
9389
9390
9391
9392
9393
9394
9395
9396
9397
9398
9399
9400
9401
9402
9403
9404
9405
9406
9407
9408
9409
9410
9411
9412
9413
9414
9415
9416
9417
9418
9419
9420
9421
9422
9423
9424
9425
9426
9427
9428
9429
9430
9431
9432
9433
9434
9435
9436
9437
9438
9439
9440
9441
9442
9443
9444
9445
9446
9447
9448
9449
9450
9451
9452
9453
9454
9455
9456
9457
9458
9459
9460
9461
9462
9463
9464
9465
9466
9467
9468
9469
9470
9471
9472
9473
9474
9475
9476
9477
9478
9479
9480
9481
9482
9483
9484
9485
9486
9487
9488
9489
9490
9491
9492
9493
9494
9495
9496
9497
9498
9499
9500
9501
9502
9503
9504
9505
9506
9507
9508
9509
9510
9511
9512
9513
9514
9515
9516
9517
9518
9519
9520
9521
9522
9523
9524
9525
9526
9527
9528
9529
9530
9531
9532
9533
9534
9535
9536
9537
9538
9539
9540
9541
9542
9543
9544
9545
9546
9547
9548
9549
9550
9551
9552
9553
9554
9555
9556
9557
9558
9559
9560
9561
9562
9563
9564
9565
9566
9567
9568
9569
9570
9571
9572
9573
9574
9575
9576
9577
9578
9579
9580
9581
9582
9583
9584
9585
9586
9587
9588
9589
9590
9591
9592
9593
9594
9595
9596
9597
9598
9599
9600
9601
9602
9603
9604
9605
9606
9607
9608
9609
9610
9611
9612
9613
9614
9615
9616
9617
9618
9619
9620
9621
9622
9623
9624
9625
9626
9627
9628
9629
9630
9631
9632
9633
9634
9635
9636
9637
9638
9639
9640
9641
9642
9643
9644
9645
9646
9647
9648
9649
9650
9651
9652
9653
9654
9655
9656
9657
9658
9659
9660
9661
9662
9663
9664
9665
9666
9667
9668
9669
9670
9671
9672
9673
9674
9675
9676
9677
9678
9679
9680
9681
9682
9683
9684
9685
9686
9687
9688
9689
9690
9691
9692
9693
9694
9695
9696
9697
9698
9699
9700
9701
9702
9703
9704
9705
9706
9707
9708
9709
9710
9711
9712
9713
9714
9715
9716
9717
9718
9719
9720
9721
9722
9723
9724
9725
9726
9727
9728
9729
9730
9731
9732
9733
9734
9735
9736
9737
9738
9739
9740
9741
9742
9743
9744
9745
9746
9747
9748
9749
9750
9751
9752
9753
9754
9755
9756
9757
9758
9759
9760
9761
9762
9763
9764
9765
9766
9767
9768
9769
9770
9771
9772
9773
9774
9775
9776
9777
9778
9779
9780
9781
9782
9783
9784
9785
9786
9787
9788
9789
9790
9791
9792
9793
9794
9795
9796
9797
9798
9799
9800
9801
9802
9803
9804
9805
9806
9807
9808
9809
9810
9811
9812
9813
9814
9815
9816
9817
9818
9819
9820
9821
9822
9823
9824
9825
9826
9827
9828
9829
9830
9831
9832
9833
9834
9835
9836
9837
9838
9839
9840
9841
9842
9843
9844
9845
9846
9847
9848
9849
9850
9851
9852
9853
9854
9855
9856
9857
9858
9859
9860
9861
9862
9863
9864
9865
9866
9867
9868
9869
9870
9871
9872
9873
9874
9875
9876
9877
9878
9879
9880
9881
9882
9883
9884
9885
9886
9887
9888
9889
9890
9891
9892
9893
9894
9895
9896
9897
9898
9899
9900
9901
9902
9903
9904
9905
9906
9907
9908
9909
9910
9911
9912
9913
9914
9915
9916
9917
9918
9919
9920
9921
9922
9923
9924
9925
9926
9927
9928
9929
9930
9931
9932
9933
9934
9935
9936
9937
9938
9939
9940
9941
9942
9943
9944
9945
9946
9947
9948
9949
9950
9951
9952
9953
9954
9955
9956
9957
9958
9959
9960
9961
9962
9963
9964
9965
9966
9967
9968
9969
9970
9971
9972
9973
9974
9975
9976
9977
9978
9979
9980
9981
9982
9983
9984
9985
9986
9987
9988
9989
9990
9991
9992
9993
9994
9995
9996
9997
9998
9999
10000
10001
10002
10003
10004
10005
10006
10007
10008
10009
10010
10011
10012
10013
10014
10015
10016
10017
10018
10019
10020
10021
10022
10023
10024
10025
10026
10027
10028
10029
10030
10031
10032
10033
10034
10035
10036
10037
10038
10039
10040
10041
10042
10043
10044
10045
10046
10047
10048
10049
10050
10051
10052
10053
10054
10055
10056
10057
10058
10059
10060
10061
10062
10063
10064
10065
10066
10067
10068
10069
10070
10071
10072
10073
10074
10075
10076
10077
10078
10079
10080
10081
10082
10083
10084
10085
10086
10087
10088
10089
10090
10091
10092
10093
10094
10095
10096
10097
10098
10099
10100
10101
10102
10103
10104
10105
10106
10107
10108
10109
10110
10111
10112
10113
10114
10115
10116
10117
10118
10119
10120
10121
10122
10123
10124
10125
10126
10127
10128
10129
10130
10131
10132
10133
10134
10135
10136
10137
10138
10139
10140
10141
10142
10143
10144
10145
10146
10147
10148
10149
10150
10151
10152
10153
10154
10155
10156
10157
10158
10159
10160
10161
10162
10163
10164
10165
10166
10167
10168
10169
10170
10171
10172
10173
10174
10175
10176
10177
10178
10179
10180
10181
10182
10183
10184
10185
10186
10187
10188
10189
10190
10191
10192
10193
10194
10195
10196
10197
10198
10199
10200
10201
10202
10203
10204
10205
10206
10207
10208
10209
10210
10211
10212
10213
10214
10215
10216
10217
10218
10219
10220
10221
10222
10223
10224
10225
10226
10227
10228
10229
10230
10231
10232
10233
10234
10235
10236
10237
10238
10239
10240
10241
10242
10243
10244
10245
10246
10247
10248
10249
10250
10251
10252
10253
10254
10255
10256
10257
10258
10259
10260
10261
10262
10263
10264
10265
10266
10267
10268
10269
10270
10271
10272
10273
10274
10275
10276
10277
10278
10279
10280
10281
10282
10283
10284
10285
10286
10287
10288
10289
10290
10291
10292
10293
10294
10295
10296
10297
10298
10299
10300
10301
10302
10303
10304
10305
10306
10307
10308
10309
10310
10311
10312
10313
10314
10315
10316
10317
10318
10319
10320
10321
10322
10323
10324
10325
10326
10327
10328
10329
10330
10331
10332
10333
10334
10335
10336
10337
10338
10339
10340
10341
10342
10343
10344
10345
10346
10347
10348
10349
10350
10351
10352
10353
10354
10355
10356
10357
10358
10359
10360
10361
10362
10363
10364
10365
10366
10367
10368
10369
10370
10371
10372
10373
10374
10375
10376
10377
10378
10379
10380
10381
10382
10383
10384
10385
10386
10387
10388
10389
10390
10391
10392
10393
10394
10395
10396
10397
10398
10399
10400
10401
10402
10403
10404
10405
10406
10407
10408
10409
10410
10411
10412
10413
10414
10415
10416
10417
10418
10419
10420
10421
10422
10423
10424
10425
10426
10427
10428
10429
10430
10431
10432
10433
10434
10435
10436
10437
10438
10439
10440
10441
10442
10443
10444
10445
10446
10447
10448
10449
10450
10451
10452
10453
10454
10455
10456
10457
10458
10459
10460
10461
10462
10463
10464
10465
10466
10467
10468
10469
10470
10471
10472
10473
10474
10475
10476
10477
10478
10479
10480
10481
10482
10483
10484
10485
10486
10487
10488
10489
10490
10491
10492
10493
10494
10495
10496
10497
10498
10499
10500
10501
10502
10503
10504
10505
10506
10507
10508
10509
10510
10511
10512
10513
10514
10515
10516
10517
10518
10519
10520
10521
10522
10523
10524
10525
10526
10527
10528
10529
10530
10531
10532
10533
10534
10535
10536
10537
10538
10539
10540
10541
10542
10543
10544
10545
10546
10547
10548
10549
10550
10551
10552
10553
10554
10555
10556
10557
10558
10559
10560
10561
10562
10563
10564
10565
10566
10567
10568
10569
| | \input texinfo
@c -*-texinfo-*-
@c %**start of header
@setfilename guix.info
@documentencoding UTF-8
@settitle GNU Guix Reference Manual
@c %**end of header
@include version.texi
@copying
Copyright @copyright{} 2012, 2013, 2014, 2015, 2016 Ludovic Courtès@*
Copyright @copyright{} 2013, 2014 Andreas Enge@*
Copyright @copyright{} 2013 Nikita Karetnikov@*
Copyright @copyright{} 2015 Mathieu Lirzin@*
Copyright @copyright{} 2014 Pierre-Antoine Rault@*
Copyright @copyright{} 2015 Taylan Ulrich Bayırlı/Kammer@*
Copyright @copyright{} 2015, 2016 Leo Famulari
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3 or
any later version published by the Free Software Foundation; with no
Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
copy of the license is included in the section entitled ``GNU Free
Documentation License''.
@end copying
@dircategory Package management
@direntry
* guix: (guix). Guix, the functional package manager.
* guix package: (guix)Invoking guix package
Managing packages with Guix.
* guix build: (guix)Invoking guix build
Building packages with Guix.
* guix system: (guix)Invoking guix system
Managing the operating system configuration.
@end direntry
@dircategory Software development
@direntry
* guix environment: (guix)Invoking guix environment
Building development environments with Guix.
@end direntry
@titlepage
@title GNU Guix Reference Manual
@subtitle Using the GNU Guix Functional Package Manager
@author The GNU Guix Developers
@page
@vskip 0pt plus 1filll
Edition @value{EDITION} @*
@value{UPDATED} @*
@insertcopying
@end titlepage
@contents
@c *********************************************************************
@node Top
@top GNU Guix
This document describes GNU Guix version @value{VERSION}, a functional
package management tool written for the GNU system.
@menu
* Introduction:: What is Guix about?
* Installation:: Installing Guix.
* Package Management:: Package installation, upgrade, etc.
* Emacs Interface:: Using Guix from Emacs.
* Programming Interface:: Using Guix in Scheme.
* Utilities:: Package management commands.
* GNU Distribution:: Software for your friendly GNU system.
* Contributing:: Your help needed!
* Acknowledgments:: Thanks!
* GNU Free Documentation License:: The license of this manual.
* Concept Index:: Concepts.
* Programming Index:: Data types, functions, and variables.
@detailmenu
--- The Detailed Node Listing ---
Installation
* Binary Installation:: Getting Guix running in no time!
* Requirements:: Software needed to build and run Guix.
* Running the Test Suite:: Testing Guix.
* Setting Up the Daemon:: Preparing the build daemon's environment.
* Invoking guix-daemon:: Running the build daemon.
* Application Setup:: Application-specific setup.
Setting Up the Daemon
* Build Environment Setup:: Preparing the isolated build environment.
* Daemon Offload Setup:: Offloading builds to remote machines.
Package Management
* Features:: How Guix will make your life brighter.
* Invoking guix package:: Package installation, removal, etc.
* Substitutes:: Downloading pre-built binaries.
* Packages with Multiple Outputs:: Single source package, multiple outputs.
* Invoking guix gc:: Running the garbage collector.
* Invoking guix pull:: Fetching the latest Guix and distribution.
* Invoking guix archive:: Exporting and importing store files.
Emacs Interface
* Initial Setup: Emacs Initial Setup. Preparing @file{~/.emacs}.
* Package Management: Emacs Package Management. Managing packages and generations.
* Popup Interface: Emacs Popup Interface. Magit-like interface for guix commands.
* Prettify Mode: Emacs Prettify. Abbreviating @file{/gnu/store/@dots{}} file names.
* Build Log Mode: Emacs Build Log. Highlighting Guix build logs.
* Completions: Emacs Completions. Completing @command{guix} shell command.
* Development: Emacs Development. Tools for Guix developers.
* Hydra: Emacs Hydra. Interface for Guix build farm.
Programming Interface
* Defining Packages:: Defining new packages.
* Build Systems:: Specifying how packages are built.
* The Store:: Manipulating the package store.
* Derivations:: Low-level interface to package derivations.
* The Store Monad:: Purely functional interface to the store.
* G-Expressions:: Manipulating build expressions.
Defining Packages
* package Reference:: The package data type.
* origin Reference:: The origin data type.
Utilities
* Invoking guix build:: Building packages from the command line.
* Invoking guix edit:: Editing package definitions.
* Invoking guix download:: Downloading a file and printing its hash.
* Invoking guix hash:: Computing the cryptographic hash of a file.
* Invoking guix import:: Importing package definitions.
* Invoking guix refresh:: Updating package definitions.
* Invoking guix lint:: Finding errors in package definitions.
* Invoking guix size:: Profiling disk usage.
* Invoking guix graph:: Visualizing the graph of packages.
* Invoking guix environment:: Setting up development environments.
* Invoking guix publish:: Sharing substitutes.
* Invoking guix challenge:: Challenging substitute servers.
* Invoking guix container:: Process isolation.
GNU Distribution
* System Installation:: Installing the whole operating system.
* System Configuration:: Configuring the operating system.
* Installing Debugging Files:: Feeding the debugger.
* Security Updates:: Deploying security fixes quickly.
* Package Modules:: Packages from the programmer's viewpoint.
* Packaging Guidelines:: Growing the distribution.
* Bootstrapping:: GNU/Linux built from scratch.
* Porting:: Targeting another platform or kernel.
System Configuration
* Using the Configuration System:: Customizing your GNU system.
* operating-system Reference:: Detail of operating-system declarations.
* File Systems:: Configuring file system mounts.
* Mapped Devices:: Block device extra processing.
* User Accounts:: Specifying user accounts.
* Locales:: Language and cultural convention settings.
* Services:: Specifying system services.
* Setuid Programs:: Programs running with root privileges.
* X.509 Certificates:: Authenticating HTTPS servers.
* Name Service Switch:: Configuring libc's name service switch.
* Initial RAM Disk:: Linux-Libre bootstrapping.
* GRUB Configuration:: Configuring the boot loader.
* Invoking guix system:: Instantiating a system configuration.
* Running GuixSD in a VM:: How to run GuixSD in a virtual machine.
* Defining Services:: Adding new service definitions.
Services
* Base Services:: Essential system services.
* Networking Services:: Network setup, SSH daemon, etc.
* X Window:: Graphical display.
* Desktop Services:: D-Bus and desktop services.
* Database Services:: SQL databases.
* Mail Services:: IMAP, POP3, SMTP, and all that.
* Web Services:: Web servers.
* Various Services:: Other services.
Defining Services
* Service Composition:: The model for composing services.
* Service Types and Services:: Types and services.
* Service Reference:: API reference.
* dmd Services:: A particular type of service.
Packaging Guidelines
* Software Freedom:: What may go into the distribution.
* Package Naming:: What's in a name?
* Version Numbers:: When the name is not enough.
* Synopses and Descriptions:: Helping users find the right package.
* Python Modules:: Taming the snake.
* Perl Modules:: Little pearls.
* Fonts:: Fond of fonts.
Contributing
* Building from Git:: The latest and greatest.
* Running Guix Before It Is Installed:: Hacker tricks.
* The Perfect Setup:: The right tools.
* Coding Style:: Hygiene of the contributor.
* Submitting Patches:: Share your work.
Coding Style
* Programming Paradigm:: How to compose your elements.
* Modules:: Where to store your code?
* Data Types and Pattern Matching:: Implementing data structures.
* Formatting Code:: Writing conventions.
@end detailmenu
@end menu
@c *********************************************************************
@node Introduction
@chapter Introduction
GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
using the international phonetic alphabet (IPA).} is a functional
package management tool for the GNU system. Package management consists
of all activities that relate to building packages from sources,
honoring their build-time and run-time dependencies,
installing packages in user environments, upgrading installed packages
to new versions or rolling back to a previous set, removing unused
software packages, etc.
@cindex functional package management
The term @dfn{functional} refers to a specific package management
discipline pioneered by Nix (@pxref{Acknowledgments}).
In Guix, the package build and installation process is seen
as a function, in the mathematical sense. That function takes inputs,
such as build scripts, a compiler, and libraries, and
returns an installed package. As a pure function, its result depends
solely on its inputs---for instance, it cannot refer to software or
scripts that were not explicitly passed as inputs. A build function
always produces the same result when passed a given set of inputs. It
cannot alter the system's environment in
any way; for instance, it cannot create, modify, or delete files outside
of its build and installation directories. This is achieved by running
build processes in isolated environments (or @dfn{containers}), where only their
explicit inputs are visible.
@cindex store
The result of package build functions is @dfn{cached} in the file
system, in a special directory called @dfn{the store} (@pxref{The
Store}). Each package is installed in a directory of its own, in the
store---by default under @file{/gnu/store}. The directory name contains
a hash of all the inputs used to build that package; thus, changing an
input yields a different directory name.
This approach is the foundation of Guix's salient features: support for
transactional package upgrade and rollback, per-user installation, and
garbage collection of packages (@pxref{Features}).
Guix has a command-line interface, which allows users to build, install,
upgrade, and remove packages, as well as a Scheme programming interface.
@cindex Guix System Distribution
@cindex GuixSD
Last but not least, Guix is used to build a distribution of the GNU
system, with many GNU and non-GNU free software packages. The Guix
System Distribution, or GNU@tie{}GuixSD, takes advantage of the core
properties of Guix at the system level. With GuixSD, users
@emph{declare} all aspects of the operating system configuration, and
Guix takes care of instantiating that configuration in a reproducible,
stateless fashion. @xref{GNU Distribution}.
@c *********************************************************************
@node Installation
@chapter Installation
GNU Guix is available for download from its website at
@url{http://www.gnu.org/software/guix/}. This section describes the
software requirements of Guix, as well as how to install it and get
ready to use it.
Note that this section is concerned with the installation of the package
manager, which can be done on top of a running GNU/Linux system. If,
instead, you want to install the complete GNU operating system,
@pxref{System Installation}.
@menu
* Binary Installation:: Getting Guix running in no time!
* Requirements:: Software needed to build and run Guix.
* Running the Test Suite:: Testing Guix.
* Setting Up the Daemon:: Preparing the build daemon's environment.
* Invoking guix-daemon:: Running the build daemon.
* Application Setup:: Application-specific setup.
@end menu
@node Binary Installation
@section Binary Installation
This section describes how to install Guix on an arbitrary system from a
self-contained tarball providing binaries for Guix and for all its
dependencies. This is often quicker than installing from source, which
is described in the next sections. The only requirement is to have
GNU@tie{}tar and Xz.
Installing goes along these lines:
@enumerate
@item
Download the binary tarball from
@indicateurl{ftp://alpha.gnu.org/gnu/guix/guix-binary-@value{VERSION}.@var{system}.tar.xz},
where @var{system} is @code{x86_64-linux} for an @code{x86_64} machine
already running the kernel Linux, and so on.
Make sure to download the associated @file{.sig} file and to verify the
authenticity of the tarball against it, along these lines:
@example
$ wget ftp://alpha.gnu.org/gnu/guix/guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
$ gpg --verify guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
@end example
If that command fails because you don't have the required public key,
then run this command to import it:
@example
$ gpg --keyserver keys.gnupg.net --recv-keys 3D9AEBB5
@end example
@noindent
and rerun the @code{gpg --verify} command.
@item
As @code{root}, run:
@example
# cd /tmp
# tar --warning=no-timestamp -xf \
guix-binary-@value{VERSION}.@var{system}.tar.xz
# mv var/guix /var/ && mv gnu /
@end example
This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
The latter contains a ready-to-use profile for @code{root} (see next
step.)
Do @emph{not} unpack the tarball on a working Guix system since that
would overwrite its own essential files.
The @code{--warning=no-timestamp} option makes sure GNU@tie{}tar does
not emit warnings about ``implausibly old time stamps'' (such
warnings were triggered by GNU@tie{}tar 1.26 and older; recent
versions are fine.)
They stem from the fact that all the
files in the archive have their modification time set to zero (which
means January 1st, 1970.) This is done on purpose to make sure the
archive content is independent of its creation time, thus making it
reproducible.
@item
Make @code{root}'s profile available under @file{~/.guix-profile}:
@example
# ln -sf /var/guix/profiles/per-user/root/guix-profile \
~root/.guix-profile
@end example
@item
Create the group and user accounts for build users as explained below
(@pxref{Build Environment Setup}).
@item
Run the daemon:
@example
# ~root/.guix-profile/bin/guix-daemon --build-users-group=guixbuild
@end example
On hosts using the systemd init system, drop
@file{~root/.guix-profile/lib/systemd/system/guix-daemon.service} in
@file{/etc/systemd/system}.
Likewise, on hosts using the Upstart init system, drop
@file{~root/.guix-profile/lib/upstart/system/guix-daemon.conf} in
@file{/etc/init}.
@item
Make the @command{guix} command available to other users on the machine,
for instance with:
@example
# mkdir -p /usr/local/bin
# cd /usr/local/bin
# ln -s /var/guix/profiles/per-user/root/guix-profile/bin/guix
@end example
It is also a good idea to make the Info version of this manual available
there:
@example
# mkdir -p /usr/local/share/info
# cd /usr/local/share/info
# for i in /var/guix/profiles/per-user/root/guix-profile/share/info/* ;
do ln -s $i ; done
@end example
That way, assuming @file{/usr/local/share/info} is in the search path,
running @command{info guix} will open this manual (@pxref{Other Info
Directories,,, texinfo, GNU Texinfo}, for more details on changing the
Info search path.)
@item
To use substitutes from @code{hydra.gnu.org} (@pxref{Substitutes}),
authorize them:
@example
# guix archive --authorize < ~root/.guix-profile/share/guix/hydra.gnu.org.pub
@end example
@end enumerate
And that's it! For additional tips and tricks, @pxref{Application
Setup}.
The @code{guix} package must remain available in @code{root}'s
profile, or it would become subject to garbage collection---in which
case you would find yourself badly handicapped by the lack of the
@command{guix} command.
The tarball in question can be (re)produced and verified simply by
running the following command in the Guix source tree:
@example
make guix-binary.@var{system}.tar.xz
@end example
@node Requirements
@section Requirements
This section lists requirements when building Guix from source. The
build procedure for Guix is the same as for other GNU software, and is
not covered here. Please see the files @file{README} and @file{INSTALL}
in the Guix source tree for additional details.
GNU Guix depends on the following packages:
@itemize
@item @url{http://gnu.org/software/guile/, GNU Guile}, version 2.0.7 or later;
@item @url{http://gnupg.org/, GNU libgcrypt};
@item @url{http://www.gnu.org/software/make/, GNU Make}.
@end itemize
The following dependencies are optional:
@itemize
@item
Installing
@url{http://savannah.nongnu.org/projects/guile-json/, Guile-JSON} will
allow you to use the @command{guix import pypi} command (@pxref{Invoking
guix import}). It is of
interest primarily for developers and not for casual users.
@item
Installing @uref{http://gnutls.org/, GnuTLS-Guile} will
allow you to access @code{https} URLs with the @command{guix download}
command (@pxref{Invoking guix download}), the @command{guix import pypi}
command, and the @command{guix import cpan} command. This is primarily
of interest to developers. @xref{Guile Preparations, how to install the
GnuTLS bindings for Guile,, gnutls-guile, GnuTLS-Guile}.
@end itemize
Unless @code{--disable-daemon} was passed to @command{configure}, the
following packages are also needed:
@itemize
@item @url{http://sqlite.org, SQLite 3};
@item @url{http://www.bzip.org, libbz2};
@item @url{http://gcc.gnu.org, GCC's g++}, with support for the
C++11 standard.
@end itemize
When a working installation of @url{http://nixos.org/nix/, the Nix package
manager} is available, you
can instead configure Guix with @code{--disable-daemon}. In that case,
Nix replaces the three dependencies above.
Guix is compatible with Nix, so it is possible to share the same store
between both. To do so, you must pass @command{configure} not only the
same @code{--with-store-dir} value, but also the same
@code{--localstatedir} value. The latter is essential because it
specifies where the database that stores metadata about the store is
located, among other things. The default values for Nix are
@code{--with-store-dir=/nix/store} and @code{--localstatedir=/nix/var}.
Note that @code{--disable-daemon} is not required if
your goal is to share the store with Nix.
@node Running the Test Suite
@section Running the Test Suite
After a successful @command{configure} and @code{make} run, it is a good
idea to run the test suite. It can help catch issues with the setup or
environment, or bugs in Guix itself---and really, reporting test
failures is a good way to help improve the software. To run the test
suite, type:
@example
make check
@end example
Test cases can run in parallel: you can use the @code{-j} option of
GNU@tie{}make to speed things up. The first run may take a few minutes
on a recent machine; subsequent runs will be faster because the store
that is created for test purposes will already have various things in
cache.
It is also possible to run a subset of the tests by defining the
@code{TESTS} makefile variable as in this example:
@example
make check TESTS="tests/store.scm tests/cpio.scm"
@end example
Upon failure, please email @email{bug-guix@@gnu.org} and attach the
@file{test-suite.log} file. When @file{tests/@var{something}.scm}
fails, please also attach the @file{@var{something}.log} file available
in the top-level build directory. Please specify the Guix version being
used as well as version numbers of the dependencies
(@pxref{Requirements}) in your message.
@node Setting Up the Daemon
@section Setting Up the Daemon
@cindex daemon
Operations such as building a package or running the garbage collector
are all performed by a specialized process, the @dfn{build daemon}, on
behalf of clients. Only the daemon may access the store and its
associated database. Thus, any operation that manipulates the store
goes through the daemon. For instance, command-line tools such as
@command{guix package} and @command{guix build} communicate with the
daemon (@i{via} remote procedure calls) to instruct it what to do.
The following sections explain how to prepare the build daemon's
environment. Also @ref{Substitutes}, for information on how to allow
the daemon to download pre-built binaries.
@menu
* Build Environment Setup:: Preparing the isolated build environment.
* Daemon Offload Setup:: Offloading builds to remote machines.
@end menu
@node Build Environment Setup
@subsection Build Environment Setup
In a standard multi-user setup, Guix and its daemon---the
@command{guix-daemon} program---are installed by the system
administrator; @file{/gnu/store} is owned by @code{root} and
@command{guix-daemon} runs as @code{root}. Unprivileged users may use
Guix tools to build packages or otherwise access the store, and the
daemon will do it on their behalf, ensuring that the store is kept in a
consistent state, and allowing built packages to be shared among users.
@cindex build users
When @command{guix-daemon} runs as @code{root}, you may not want package
build processes themselves to run as @code{root} too, for obvious
security reasons. To avoid that, a special pool of @dfn{build users}
should be created for use by build processes started by the daemon.
These build users need not have a shell and a home directory: they will
just be used when the daemon drops @code{root} privileges in build
processes. Having several such users allows the daemon to launch
distinct build processes under separate UIDs, which guarantees that they
do not interfere with each other---an essential feature since builds are
regarded as pure functions (@pxref{Introduction}).
On a GNU/Linux system, a build user pool may be created like this (using
Bash syntax and the @code{shadow} commands):
@c See http://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
@c for why `-G' is needed.
@example
# groupadd --system guixbuild
# for i in `seq -w 1 10`;
do
useradd -g guixbuild -G guixbuild \
-d /var/empty -s `which nologin` \
-c "Guix build user $i" --system \
guixbuilder$i;
done
@end example
@noindent
The number of build users determines how many build jobs may run in
parallel, as specified by the @option{--max-jobs} option
(@pxref{Invoking guix-daemon, @option{--max-jobs}}). The
@code{guix-daemon} program may then be run as @code{root} with the
following command@footnote{If your machine uses the systemd init system,
dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
file in @file{/etc/systemd/system} will ensure that
@command{guix-daemon} is automatically started. Similarly, if your
machine uses the Upstart init system, drop the
@file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
file in @file{/etc/init}.}:
@example
# guix-daemon --build-users-group=guixbuild
@end example
@cindex chroot
@noindent
This way, the daemon starts build processes in a chroot, under one of
the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
environment contains nothing but:
@c Keep this list in sync with libstore/build.cc! -----------------------
@itemize
@item
a minimal @code{/dev} directory, created mostly independently from the
host @code{/dev}@footnote{``Mostly'', because while the set of files
that appear in the chroot's @code{/dev} is fixed, most of these files
can only be created if the host has them.};
@item
the @code{/proc} directory; it only shows the container's processes
since a separate PID name space is used;
@item
@file{/etc/passwd} with an entry for the current user and an entry for
user @file{nobody};
@item
@file{/etc/group} with an entry for the user's group;
@item
@file{/etc/hosts} with an entry that maps @code{localhost} to
@code{127.0.0.1};
@item
a writable @file{/tmp} directory.
@end itemize
You can influence the directory where the daemon stores build trees
@i{via} the @code{TMPDIR} environment variable. However, the build tree
within the chroot is always @file{/tmp/guix-build-@var{name}.drv-0},
where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
This way, the value of @code{TMPDIR} does not leak inside build
environments, which avoids discrepancies in cases where build processes
capture the name of their build tree.
@vindex http_proxy
The daemon also honors the @code{http_proxy} environment variable for
HTTP downloads it performs, be it for fixed-output derivations
(@pxref{Derivations}) or for substitutes (@pxref{Substitutes}).
If you are installing Guix as an unprivileged user, it is still possible
to run @command{guix-daemon} provided you pass @code{--disable-chroot}.
However, build processes will not be isolated from one another, and not
from the rest of the system. Thus, build processes may interfere with
each other, and may access programs, libraries, and other files
available on the system---making it much harder to view them as
@emph{pure} functions.
@node Daemon Offload Setup
@subsection Using the Offload Facility
@cindex offloading
@cindex build hook
When desired, the build daemon can @dfn{offload}
derivation builds to other machines
running Guix, using the @code{offload} @dfn{build hook}. When that
feature is enabled, a list of user-specified build machines is read from
@file{/etc/guix/machines.scm}; anytime a build is requested, for
instance via @code{guix build}, the daemon attempts to offload it to one
of the machines that satisfies the derivation's constraints, in
particular its system type---e.g., @file{x86_64-linux}. Missing
prerequisites for the build are copied over SSH to the target machine,
which then proceeds with the build; upon success the output(s) of the
build are copied back to the initial machine.
The @file{/etc/guix/machines.scm} file typically looks like this:
@example
(list (build-machine
(name "eightysix.example.org")
(system "x86_64-linux")
(user "bob")
(speed 2.)) ; incredibly fast!
(build-machine
(name "meeps.example.org")
(system "mips64el-linux")
(user "alice")
(private-key
(string-append (getenv "HOME")
"/.lsh/identity-for-guix"))))
@end example
@noindent
In the example above we specify a list of two build machines, one for
the @code{x86_64} architecture and one for the @code{mips64el}
architecture.
In fact, this file is---not surprisingly!---a Scheme file that is
evaluated when the @code{offload} hook is started. Its return value
must be a list of @code{build-machine} objects. While this example
shows a fixed list of build machines, one could imagine, say, using
DNS-SD to return a list of potential build machines discovered in the
local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
detailed below.
@deftp {Data Type} build-machine
This data type represents build machines the daemon may offload builds
to. The important fields are:
@table @code
@item name
The remote machine's host name.
@item system
The remote machine's system type---e.g., @code{"x86_64-linux"}.
@item user
The user account to use when connecting to the remote machine over SSH.
Note that the SSH key pair must @emph{not} be passphrase-protected, to
allow non-interactive logins.
@end table
A number of optional fields may be specified:
@table @code
@item port
Port number of the machine's SSH server (default: 22).
@item private-key
The SSH private key file to use when connecting to the machine.
Currently offloading uses GNU@tie{}lsh as its SSH client
(@pxref{Invoking lsh,,, GNU lsh Manual}). Thus, the key file here must
be an lsh key file. This may change in the future, though.
@item parallel-builds
The number of builds that may run in parallel on the machine (1 by
default.)
@item speed
A ``relative speed factor''. The offload scheduler will tend to prefer
machines with a higher speed factor.
@item features
A list of strings denoting specific features supported by the machine.
An example is @code{"kvm"} for machines that have the KVM Linux modules
and corresponding hardware support. Derivations can request features by
name, and they will be scheduled on matching build machines.
@end table
@end deftp
The @code{guix} command must be in the search path on the build
machines, since offloading works by invoking the @code{guix archive} and
@code{guix build} commands. In addition, the Guix modules must be in
@code{$GUILE_LOAD_PATH} on the build machine---you can check whether
this is the case by running:
@example
lsh build-machine guile -c '(use-modules (guix config))'
@end example
There's one last thing to do once @file{machines.scm} is in place. As
explained above, when offloading, files are transferred back and forth
between the machine stores. For this to work, you first need to
generate a key pair on each machine to allow the daemon to export signed
archives of files from the store (@pxref{Invoking guix archive}):
@example
# guix archive --generate-key
@end example
@noindent
Each build machine must authorize the key of the master machine so that
it accepts store items it receives from the master:
@example
# guix archive --authorize < master-public-key.txt
@end example
@noindent
Likewise, the master machine must authorize the key of each build machine.
All the fuss with keys is here to express pairwise mutual trust
relations between the master and the build machines. Concretely, when
the master receives files from a build machine (and @i{vice versa}), its
build daemon can make sure they are genuine, have not been tampered
with, and that they are signed by an authorized key.
@node Invoking guix-daemon
@section Invoking @command{guix-daemon}
The @command{guix-daemon} program implements all the functionality to
access the store. This includes launching build processes, running the
garbage collector, querying the availability of a build result, etc. It
is normally run as @code{root} like this:
@example
# guix-daemon --build-users-group=guixbuild
@end example
@noindent
For details on how to set it up, @pxref{Setting Up the Daemon}.
@cindex chroot
@cindex container, build environment
@cindex build environment
@cindex reproducible builds
By default, @command{guix-daemon} launches build processes under
different UIDs, taken from the build group specified with
@code{--build-users-group}. In addition, each build process is run in a
chroot environment that only contains the subset of the store that the
build process depends on, as specified by its derivation
(@pxref{Programming Interface, derivation}), plus a set of specific
system directories. By default, the latter contains @file{/dev} and
@file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
@dfn{container}: in addition to having its own file system tree, it has
a separate mount name space, its own PID name space, network name space,
etc. This helps achieve reproducible builds (@pxref{Features}).
When the daemon performs a build on behalf of the user, it creates a
build directory under @file{/tmp} or under the directory specified by
its @code{TMPDIR} environment variable; this directory is shared with
the container for the duration of the build. Be aware that using a
directory other than @file{/tmp} can affect build results---for example,
with a longer directory name, a build process that uses Unix-domain
sockets might hit the name length limitation for @code{sun_path}, which
it would otherwise not hit.
The build directory is automatically deleted upon completion, unless the
build failed and the client specified @option{--keep-failed}
(@pxref{Invoking guix build, @option{--keep-failed}}).
The following command-line options are supported:
@table @code
@item --build-users-group=@var{group}
Take users from @var{group} to run build processes (@pxref{Setting Up
the Daemon, build users}).
@item --no-substitutes
@cindex substitutes
Do not use substitutes for build products. That is, always build things
locally instead of allowing downloads of pre-built binaries
(@pxref{Substitutes}).
By default substitutes are used, unless the client---such as the
@command{guix package} command---is explicitly invoked with
@code{--no-substitutes}.
When the daemon runs with @code{--no-substitutes}, clients can still
explicitly enable substitution @i{via} the @code{set-build-options}
remote procedure call (@pxref{The Store}).
@item --substitute-urls=@var{urls}
@anchor{daemon-substitute-urls}
Consider @var{urls} the default whitespace-separated list of substitute
source URLs. When this option is omitted, @indicateurl{http://hydra.gnu.org}
is used.
This means that substitutes may be downloaded from @var{urls}, as long
as they are signed by a trusted signature (@pxref{Substitutes}).
@cindex build hook
@item --no-build-hook
Do not use the @dfn{build hook}.
The build hook is a helper program that the daemon can start and to
which it submits build requests. This mechanism is used to offload
builds to other machines (@pxref{Daemon Offload Setup}).
@item --cache-failures
Cache build failures. By default, only successful builds are cached.
When this option is used, @command{guix gc --list-failures} can be used
to query the set of store items marked as failed; @command{guix gc
--clear-failures} removes store items from the set of cached failures.
@xref{Invoking guix gc}.
@item --cores=@var{n}
@itemx -c @var{n}
Use @var{n} CPU cores to build each derivation; @code{0} means as many
as available.
The default value is @code{0}, but it may be overridden by clients, such
as the @code{--cores} option of @command{guix build} (@pxref{Invoking
guix build}).
The effect is to define the @code{NIX_BUILD_CORES} environment variable
in the build process, which can then use it to exploit internal
parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
@item --max-jobs=@var{n}
@itemx -M @var{n}
Allow at most @var{n} build jobs in parallel. The default value is
@code{1}. Setting it to @code{0} means that no builds will be performed
locally; instead, the daemon will offload builds (@pxref{Daemon Offload
Setup}), or simply fail.
@item --rounds=@var{N}
Build each derivation @var{n} times in a row, and raise an error if
consecutive build results are not bit-for-bit identical. Note that this
setting can be overridden by clients such as @command{guix build}
(@pxref{Invoking guix build}).
@item --debug
Produce debugging output.
This is useful to debug daemon start-up issues, but then it may be
overridden by clients, for example the @code{--verbosity} option of
@command{guix build} (@pxref{Invoking guix build}).
@item --chroot-directory=@var{dir}
Add @var{dir} to the build chroot.
Doing this may change the result of build processes---for instance if
they use optional dependencies found in @var{dir} when it is available,
and not otherwise. For that reason, it is not recommended to do so.
Instead, make sure that each derivation declares all the inputs that it
needs.
@item --disable-chroot
Disable chroot builds.
Using this option is not recommended since, again, it would allow build
processes to gain access to undeclared dependencies. It is necessary,
though, when @command{guix-daemon} is running under an unprivileged user
account.
@item --disable-log-compression
Disable compression of the build logs.
Unless @code{--lose-logs} is used, all the build logs are kept in the
@var{localstatedir}. To save space, the daemon automatically compresses
them with bzip2 by default. This option disables that.
@item --disable-deduplication
@cindex deduplication
Disable automatic file ``deduplication'' in the store.
By default, files added to the store are automatically ``deduplicated'':
if a newly added file is identical to another one found in the store,
the daemon makes the new file a hard link to the other file. This can
noticeably reduce disk usage, at the expense of slightly increased
input/output load at the end of a build process. This option disables
this optimization.
@item --gc-keep-outputs[=yes|no]
Tell whether the garbage collector (GC) must keep outputs of live
derivations.
When set to ``yes'', the GC will keep the outputs of any live derivation
available in the store---the @code{.drv} files. The default is ``no'',
meaning that derivation outputs are kept only if they are GC roots.
@item --gc-keep-derivations[=yes|no]
Tell whether the garbage collector (GC) must keep derivations
corresponding to live outputs.
When set to ``yes'', as is the case by default, the GC keeps
derivations---i.e., @code{.drv} files---as long as at least one of their
outputs is live. This allows users to keep track of the origins of
items in their store. Setting it to ``no'' saves a bit of disk space.
Note that when both @code{--gc-keep-derivations} and
@code{--gc-keep-outputs} are used, the effect is to keep all the build
prerequisites (the sources, compiler, libraries, and other build-time
tools) of live objects in the store, regardless of whether these
prerequisites are live. This is convenient for developers since it
saves rebuilds or downloads.
@item --impersonate-linux-2.6
On Linux-based systems, impersonate Linux 2.6. This means that the
kernel's @code{uname} system call will report 2.6 as the release number.
This might be helpful to build programs that (usually wrongfully) depend
on the kernel version number.
@item --lose-logs
Do not keep build logs. By default they are kept under
@code{@var{localstatedir}/guix/log}.
@item --system=@var{system}
Assume @var{system} as the current system type. By default it is the
architecture/kernel pair found at configure time, such as
@code{x86_64-linux}.
@item --listen=@var{socket}
Listen for connections on @var{socket}, the file name of a Unix-domain
socket. The default socket is
@file{@var{localstatedir}/daemon-socket/socket}. This option is only
useful in exceptional circumstances, such as if you need to run several
daemons on the same machine.
@end table
@node Application Setup
@section Application Setup
When using Guix on top of GNU/Linux distribution other than GuixSD---a
so-called @dfn{foreign distro}---a few additional steps are needed to
get everything in place. Here are some of them.
@subsection Locales
@anchor{locales-and-locpath}
@cindex locales, when not on GuixSD
@vindex LOCPATH
@vindex GUIX_LOCPATH
Packages installed @i{via} Guix will not use the host system's locale
data. Instead, you must first install one of the locale packages
available with Guix and then define the @code{GUIX_LOCPATH} environment
variable:
@example
$ guix package -i glibc-locales
$ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
@end example
Note that the @code{glibc-locales} package contains data for all the
locales supported by the GNU@tie{}libc and weighs in at around
110@tie{}MiB. Alternately, the @code{glibc-utf8-locales} is smaller but
limited to a few UTF-8 locales.
The @code{GUIX_LOCPATH} variable plays a role similar to @code{LOCPATH}
(@pxref{Locale Names, @code{LOCPATH},, libc, The GNU C Library Reference
Manual}). There are two important differences though:
@enumerate
@item
@code{GUIX_LOCPATH} is honored only by Guix's libc, and not by the libc
provided by foreign distros. Thus, using @code{GUIX_LOCPATH} allows you
to make sure the foreign distro's programs will not end up loading
incompatible locale data.
@item
libc suffixes each entry of @code{GUIX_LOCPATH} with @code{/X.Y}, where
@code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
should your Guix profile contain a mixture of programs linked against
different libc version, each libc version will only try to load locale
data in the right format.
@end enumerate
This is important because the locale data format used by different libc
versions may be incompatible.
@subsection X11 Fonts
The majority of graphical applications use Fontconfig to locate and
load fonts and perform X11-client-side rendering. Guix's
@code{fontconfig} package looks for fonts in @file{$HOME/.guix-profile}
by default. Thus, to allow graphical applications installed with Guix
to display fonts, you will have to install fonts with Guix as well.
Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
@code{font-gnu-freefont-ttf}.
To display text written in Chinese languages, Japanese, or Korean in
graphical applications, consider installing
@code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
has multiple outputs, one per language family (@pxref{Packages with
Multiple Outputs}). For instance, the following command installs fonts
for Chinese languages:
@example
guix package -i font-adobe-source-han-sans:cn
@end example
@c TODO What else?
@c *********************************************************************
@node Package Management
@chapter Package Management
The purpose of GNU Guix is to allow users to easily install, upgrade, and
remove software packages, without having to know about their build
procedure or dependencies. Guix also goes beyond this obvious set of
features.
This chapter describes the main features of Guix, as well as the package
management tools it provides. Two user interfaces are provided for
routine package management tasks: A command-line interface described below
(@pxref{Invoking guix package, @code{guix package}}), as well as a visual user
interface in Emacs described in a subsequent chapter (@pxref{Emacs Interface}).
@menu
* Features:: How Guix will make your life brighter.
* Invoking guix package:: Package installation, removal, etc.
* Substitutes:: Downloading pre-built binaries.
* Packages with Multiple Outputs:: Single source package, multiple outputs.
* Invoking guix gc:: Running the garbage collector.
* Invoking guix pull:: Fetching the latest Guix and distribution.
* Invoking guix archive:: Exporting and importing store files.
@end menu
@node Features
@section Features
When using Guix, each package ends up in the @dfn{package store}, in its
own directory---something that resembles
@file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string
(note that Guix comes with an Emacs extension to shorten those file
names, @pxref{Emacs Prettify}.)
Instead of referring to these directories, users have their own
@dfn{profile}, which points to the packages that they actually want to
use. These profiles are stored within each user's home directory, at
@code{$HOME/.guix-profile}.
For example, @code{alice} installs GCC 4.7.2. As a result,
@file{/home/alice/.guix-profile/bin/gcc} points to
@file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
@code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
simply continues to point to
@file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
coexist on the same system without any interference.
The @command{guix package} command is the central tool to manage
packages (@pxref{Invoking guix package}). It operates on those per-user
profiles, and can be used @emph{with normal user privileges}.
The command provides the obvious install, remove, and upgrade
operations. Each invocation is actually a @emph{transaction}: either
the specified operation succeeds, or nothing happens. Thus, if the
@command{guix package} process is terminated during the transaction,
or if a power outage occurs during the transaction, then the user's
profile remains in its previous state, and remains usable.
In addition, any package transaction may be @emph{rolled back}. So, if,
for example, an upgrade installs a new version of a package that turns
out to have a serious bug, users may roll back to the previous instance
of their profile, which was known to work well. Similarly, the global
system configuration is subject to transactional upgrades and roll-back
(@pxref{Using the Configuration System}).
All those packages in the package store may be @emph{garbage-collected}.
Guix can determine which packages are still referenced by the user
profiles, and remove those that are provably no longer referenced
(@pxref{Invoking guix gc}). Users may also explicitly remove old
generations of their profile so that the packages they refer to can be
collected.
@cindex reproducibility
@cindex reproducible builds
Finally, Guix takes a @dfn{purely functional} approach to package
management, as described in the introduction (@pxref{Introduction}).
Each @file{/gnu/store} package directory name contains a hash of all the
inputs that were used to build that package---compiler, libraries, build
scripts, etc. This direct correspondence allows users to make sure a
given package installation matches the current state of their
distribution. It also helps maximize @dfn{build reproducibility}:
thanks to the isolated build environments that are used, a given build
is likely to yield bit-identical files when performed on different
machines (@pxref{Invoking guix-daemon, container}).
@cindex substitutes
This foundation allows Guix to support @dfn{transparent binary/source
deployment}. When a pre-built binary for a @file{/gnu/store} item is
available from an external source---a @dfn{substitute}, Guix just
downloads it and unpacks it;
otherwise, it builds the package from source, locally
(@pxref{Substitutes}).
Control over the build environment is a feature that is also useful for
developers. The @command{guix environment} command allows developers of
a package to quickly set up the right development environment for their
package, without having to manually install the package's dependencies
in their profile (@pxref{Invoking guix environment}).
@node Invoking guix package
@section Invoking @command{guix package}
The @command{guix package} command is the tool that allows users to
install, upgrade, and remove packages, as well as rolling back to
previous configurations. It operates only on the user's own profile,
and works with normal user privileges (@pxref{Features}). Its syntax
is:
@example
guix package @var{options}
@end example
Primarily, @var{options} specifies the operations to be performed during
the transaction. Upon completion, a new profile is created, but
previous @dfn{generations} of the profile remain available, should the user
want to roll back.
For example, to remove @code{lua} and install @code{guile} and
@code{guile-cairo} in a single transaction:
@example
guix package -r lua -i guile guile-cairo
@end example
@command{guix package} also supports a @dfn{declarative approach}
whereby the user specifies the exact set of packages to be available and
passes it @i{via} the @option{--manifest} option
(@pxref{profile-manifest, @option{--manifest}}).
For each user, a symlink to the user's default profile is automatically
created in @file{$HOME/.guix-profile}. This symlink always points to the
current generation of the user's default profile. Thus, users can add
@file{$HOME/.guix-profile/bin} to their @code{PATH} environment
variable, and so on.
@cindex search paths
If you are not using the Guix System Distribution, consider adding the
following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
shells get all the right environment variable definitions:
@example
GUIX_PROFILE="$HOME/.guix-profile" \
source "$HOME/.guix-profile/etc/profile"
@end example
In a multi-user setup, user profiles are stored in a place registered as
a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
to (@pxref{Invoking guix gc}). That directory is normally
@code{@var{localstatedir}/profiles/per-user/@var{user}}, where
@var{localstatedir} is the value passed to @code{configure} as
@code{--localstatedir}, and @var{user} is the user name. The
@file{per-user} directory is created when @command{guix-daemon} is
started, and the @var{user} sub-directory is created by @command{guix
package}.
The @var{options} can be among the following:
@table @code
@item --install=@var{package} @dots{}
@itemx -i @var{package} @dots{}
Install the specified @var{package}s.
Each @var{package} may specify either a simple package name, such as
@code{guile}, or a package name followed by a hyphen and version number,
such as @code{guile-1.8.8} or simply @code{guile-1.8} (in the latter
case, the newest version prefixed by @code{1.8} is selected.)
If no version number is specified, the
newest available version will be selected. In addition, @var{package}
may contain a colon, followed by the name of one of the outputs of the
package, as in @code{gcc:doc} or @code{binutils-2.22:lib}
(@pxref{Packages with Multiple Outputs}). Packages with a corresponding
name (and optionally version) are searched for among the GNU
distribution modules (@pxref{Package Modules}).
@cindex propagated inputs
Sometimes packages have @dfn{propagated inputs}: these are dependencies
that automatically get installed along with the required package
(@pxref{package-propagated-inputs, @code{propagated-inputs} in
@code{package} objects}, for information about propagated inputs in
package definitions).
@anchor{package-cmd-propagated-inputs}
An example is the GNU MPC library: its C header files refer to those of
the GNU MPFR library, which in turn refer to those of the GMP library.
Thus, when installing MPC, the MPFR and GMP libraries also get installed
in the profile; removing MPC also removes MPFR and GMP---unless they had
also been explicitly installed independently.
Besides, packages sometimes rely on the definition of environment
variables for their search paths (see explanation of
@code{--search-paths} below). Any missing or possibly incorrect
environment variable definitions are reported here.
@c XXX: keep me up-to-date
Finally, when installing a GNU package, the tool reports the
availability of a newer upstream version. In the future, it may provide
the option of installing directly from the upstream version, even if
that version is not yet in the distribution.
@item --install-from-expression=@var{exp}
@itemx -e @var{exp}
Install the package @var{exp} evaluates to.
@var{exp} must be a Scheme expression that evaluates to a
@code{<package>} object. This option is notably useful to disambiguate
between same-named variants of a package, with expressions such as
@code{(@@ (gnu packages base) guile-final)}.
Note that this option installs the first output of the specified
package, which may be insufficient when needing a specific output of a
multiple-output package.
@item --install-from-file=@var{file}
@itemx -f @var{file}
Install the package that the code within @var{file} evaluates to.
As an example, @var{file} might contain a definition like this
(@pxref{Defining Packages}):
@example
@verbatiminclude package-hello.scm
@end example
Developers may find it useful to include such a @file{package.scm} file
in the root of their project's source tree that can be used to test
development snapshots and create reproducible development environments
(@pxref{Invoking guix environment}).
@item --remove=@var{package} @dots{}
@itemx -r @var{package} @dots{}
Remove the specified @var{package}s.
As for @code{--install}, each @var{package} may specify a version number
and/or output name in addition to the package name. For instance,
@code{-r glibc:debug} would remove the @code{debug} output of
@code{glibc}.
@item --upgrade[=@var{regexp} @dots{}]
@itemx -u [@var{regexp} @dots{}]
Upgrade all the installed packages. If one or more @var{regexp}s are
specified, upgrade only installed packages whose name matches a
@var{regexp}. Also see the @code{--do-not-upgrade} option below.
Note that this upgrades package to the latest version of packages found
in the distribution currently installed. To update your distribution,
you should regularly run @command{guix pull} (@pxref{Invoking guix
pull}).
@item --do-not-upgrade[=@var{regexp} @dots{}]
When used together with the @code{--upgrade} option, do @emph{not}
upgrade any packages whose name matches a @var{regexp}. For example, to
upgrade all packages in the current profile except those containing the
substring ``emacs'':
@example
$ guix package --upgrade . --do-not-upgrade emacs
@end example
@item @anchor{profile-manifest}--manifest=@var{file}
@itemx -m @var{file}
@cindex profile declaration
@cindex profile manifest
Create a new generation of the profile from the manifest object
returned by the Scheme code in @var{file}.
This allows you to @emph{declare} the profile's contents rather than
constructing it through a sequence of @code{--install} and similar
commands. The advantage is that @var{file} can be put under version
control, copied to different machines to reproduce the same profile, and
so on.
@c FIXME: Add reference to (guix profile) documentation when available.
@var{file} must return a @dfn{manifest} object, which is roughly a list
of packages:
@findex packages->manifest
@example
(use-package-modules guile emacs)
(packages->manifest
(list emacs
guile-2.0
;; Use a specific package output.
(list guile-2.0 "debug")))
@end example
@item --roll-back
Roll back to the previous @dfn{generation} of the profile---i.e., undo
the last transaction.
When combined with options such as @code{--install}, roll back occurs
before any other actions.
When rolling back from the first generation that actually contains
installed packages, the profile is made to point to the @dfn{zeroth
generation}, which contains no files apart from its own meta-data.
Installing, removing, or upgrading packages from a generation that has
been rolled back to overwrites previous future generations. Thus, the
history of a profile's generations is always linear.
@item --switch-generation=@var{pattern}
@itemx -S @var{pattern}
Switch to a particular generation defined by @var{pattern}.
@var{pattern} may be either a generation number or a number prefixed
with ``+'' or ``-''. The latter means: move forward/backward by a
specified number of generations. For example, if you want to return to
the latest generation after @code{--roll-back}, use
@code{--switch-generation=+1}.
The difference between @code{--roll-back} and
@code{--switch-generation=-1} is that @code{--switch-generation} will
not make a zeroth generation, so if a specified generation does not
exist, the current generation will not be changed.
@item --search-paths[=@var{kind}]
@cindex search paths
Report environment variable definitions, in Bash syntax, that may be
needed in order to use the set of installed packages. These environment
variables are used to specify @dfn{search paths} for files used by some
of the installed packages.
For example, GCC needs the @code{CPATH} and @code{LIBRARY_PATH}
environment variables to be defined so it can look for headers and
libraries in the user's profile (@pxref{Environment Variables,,, gcc,
Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
library are installed in the profile, then @code{--search-paths} will
suggest setting these variables to @code{@var{profile}/include} and
@code{@var{profile}/lib}, respectively.
The typical use case is to define these environment variables in the
shell:
@example
$ eval `guix package --search-paths`
@end example
@var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
meaning that the returned environment variable definitions will either
be exact settings, or prefixes or suffixes of the current value of these
variables. When omitted, @var{kind} defaults to @code{exact}.
This option can also be used to compute the @emph{combined} search paths
of several profiles. Consider this example:
@example
$ guix package -p foo -i guile
$ guix package -p bar -i guile-json
$ guix package -p foo -p bar --search-paths
@end example
The last command above reports about the @code{GUILE_LOAD_PATH}
variable, even though, taken individually, neither @file{foo} nor
@file{bar} would lead to that recommendation.
@item --profile=@var{profile}
@itemx -p @var{profile}
Use @var{profile} instead of the user's default profile.
@item --verbose
Produce verbose output. In particular, emit the environment's build log
on the standard error port.
@item --bootstrap
Use the bootstrap Guile to build the profile. This option is only
useful to distribution developers.
@end table
In addition to these actions @command{guix package} supports the
following options to query the current state of a profile, or the
availability of packages:
@table @option
@item --search=@var{regexp}
@itemx -s @var{regexp}
@cindex searching for packages
List the available packages whose name, synopsis, or description matches
@var{regexp}. Print all the meta-data of matching packages in
@code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
GNU recutils manual}).
This allows specific fields to be extracted using the @command{recsel}
command, for instance:
@example
$ guix package -s malloc | recsel -p name,version
name: glibc
version: 2.17
name: libgc
version: 7.2alpha6
@end example
Similarly, to show the name of all the packages available under the
terms of the GNU@tie{}LGPL version 3:
@example
$ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
name: elfutils
name: gmp
@dots{}
@end example
It is also possible to refine search results using several @code{-s}
flags. For example, the following command returns a list of board
games:
@example
$ guix package -s '\<board\>' -s game | recsel -p name
name: gnubg
@dots{}
@end example
If we were to omit @code{-s game}, we would also get software packages
that deal with printed circuit boards; removing the angle brackets
around @code{board} would further add packages that have to do with
keyboards.
And now for a more elaborate example. The following command searches
for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
libraries, and prints the name and synopsis of the matching packages:
@example
$ guix package -s crypto -s library | \
recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
@end example
@noindent
@xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
information on @dfn{selection expressions} for @code{recsel -e}.
@item --show=@var{package}
Show details about @var{package}, taken from the list of available packages, in
@code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
recutils manual}).
@example
$ guix package --show=python | recsel -p name,version
name: python
version: 2.7.6
name: python
version: 3.3.5
@end example
You may also specify the full name of a package to only get details about a
specific version of it:
@example
$ guix package --show=python-3.3.5 | recsel -p name,version
name: python
version: 3.3.5
@end example
@item --list-installed[=@var{regexp}]
@itemx -I [@var{regexp}]
List the currently installed packages in the specified profile, with the
most recently installed packages shown last. When @var{regexp} is
specified, list only installed packages whose name matches @var{regexp}.
For each installed package, print the following items, separated by
tabs: the package name, its version string, the part of the package that
is installed (for instance, @code{out} for the default output,
@code{include} for its headers, etc.), and the path of this package in
the store.
@item --list-available[=@var{regexp}]
@itemx -A [@var{regexp}]
List packages currently available in the distribution for this system
(@pxref{GNU Distribution}). When @var{regexp} is specified, list only
installed packages whose name matches @var{regexp}.
For each package, print the following items separated by tabs: its name,
its version string, the parts of the package (@pxref{Packages with
Multiple Outputs}), and the source location of its definition.
@item --list-generations[=@var{pattern}]
@itemx -l [@var{pattern}]
Return a list of generations along with their creation dates; for each
generation, show the installed packages, with the most recently
installed packages shown last. Note that the zeroth generation is never
shown.
For each installed package, print the following items, separated by
tabs: the name of a package, its version string, the part of the package
that is installed (@pxref{Packages with Multiple Outputs}), and the
location of this package in the store.
When @var{pattern} is used, the command returns only matching
generations. Valid patterns include:
@itemize
@item @emph{Integers and comma-separated integers}. Both patterns denote
generation numbers. For instance, @code{--list-generations=1} returns
the first one.
And @code{--list-generations=1,8,2} outputs three generations in the
specified order. Neither spaces nor trailing commas are allowed.
@item @emph{Ranges}. @code{--list-generations=2..9} prints the
specified generations and everything in between. Note that the start of
a range must be lesser than its end.
It is also possible to omit the endpoint. For example,
@code{--list-generations=2..}, returns all generations starting from the
second one.
@item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
or months by passing an integer along with the first letter of the
duration. For example, @code{--list-generations=20d} lists generations
that are up to 20 days old.
@end itemize
@item --delete-generations[=@var{pattern}]
@itemx -d [@var{pattern}]
When @var{pattern} is omitted, delete all generations except the current
one.
This command accepts the same patterns as @option{--list-generations}.
When @var{pattern} is specified, delete the matching generations. When
@var{pattern} specifies a duration, generations @emph{older} than the
specified duration match. For instance, @code{--delete-generations=1m}
deletes generations that are more than one month old.
If the current generation matches, it is @emph{not} deleted. Also, the
zeroth generation is never deleted.
Note that deleting generations prevents roll-back to them.
Consequently, this command must be used with care.
@end table
Finally, since @command{guix package} may actually start build
processes, it supports all the common build options that @command{guix
build} supports (@pxref{Invoking guix build, common build options}).
@node Substitutes
@section Substitutes
@cindex substitutes
@cindex pre-built binaries
Guix supports transparent source/binary deployment, which means that it
can either build things locally, or download pre-built items from a
server. We call these pre-built items @dfn{substitutes}---they are
substitutes for local build results. In many cases, downloading a
substitute is much faster than building things locally.
Substitutes can be anything resulting from a derivation build
(@pxref{Derivations}). Of course, in the common case, they are
pre-built package binaries, but source tarballs, for instance, which
also result from derivation builds, can be available as substitutes.
The @code{hydra.gnu.org} server is a front-end to a build farm that
builds packages from the GNU distribution continuously for some
architectures, and makes them available as substitutes (@pxref{Emacs
Hydra}, for information on how to query the continuous integration
server). This is the
default source of substitutes; it can be overridden by passing the
@option{--substitute-urls} option either to @command{guix-daemon}
(@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
or to client tools such as @command{guix package}
(@pxref{client-substitute-urls,, client @option{--substitute-urls}
option}).
@cindex security
@cindex digital signatures
To allow Guix to download substitutes from @code{hydra.gnu.org}, you
must add its public key to the access control list (ACL) of archive
imports, using the @command{guix archive} command (@pxref{Invoking guix
archive}). Doing so implies that you trust @code{hydra.gnu.org} to not
be compromised and to serve genuine substitutes.
This public key is installed along with Guix, in
@code{@var{prefix}/share/guix/hydra.gnu.org.pub}, where @var{prefix} is
the installation prefix of Guix. If you installed Guix from source,
make sure you checked the GPG signature of
@file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
Then, you can run something like this:
@example
# guix archive --authorize < hydra.gnu.org.pub
@end example
Once this is in place, the output of a command like @code{guix build}
should change from something like:
@example
$ guix build emacs --dry-run
The following derivations would be built:
/gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
/gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
/gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
/gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
@dots{}
@end example
@noindent
to something like:
@example
$ guix build emacs --dry-run
The following files would be downloaded:
/gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
/gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
/gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
/gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
@dots{}
@end example
@noindent
This indicates that substitutes from @code{hydra.gnu.org} are usable and
will be downloaded, when possible, for future builds.
Guix ignores substitutes that are not signed, or that are not signed by
one of the keys listed in the ACL. It also detects and raises an error
when attempting to use a substitute that has been tampered with.
@vindex http_proxy
Substitutes are downloaded over HTTP. The @code{http_proxy} environment
variable can be set in the environment of @command{guix-daemon} and is
honored for downloads of substitutes. Note that the value of
@code{http_proxy} in the environment where @command{guix build},
@command{guix package}, and other client commands are run has
@emph{absolutely no effect}.
The substitute mechanism can be disabled globally by running
@code{guix-daemon} with @code{--no-substitutes} (@pxref{Invoking
guix-daemon}). It can also be disabled temporarily by passing the
@code{--no-substitutes} option to @command{guix package}, @command{guix
build}, and other command-line tools.
Today, each individual's control over their own computing is at the
mercy of institutions, corporations, and groups with enough power and
determination to subvert the computing infrastructure and exploit its
weaknesses. While using @code{hydra.gnu.org} substitutes can be
convenient, we encourage users to also build on their own, or even run
their own build farm, such that @code{hydra.gnu.org} is less of an
interesting target. One way to help is by publishing the software you
build using @command{guix publish} so that others have one more choice
of server to download substitutes from (@pxref{Invoking guix publish}).
Guix has the foundations to maximize build reproducibility
(@pxref{Features}). In most cases, independent builds of a given
package or derivation should yield bit-identical results. Thus, through
a diverse set of independent package builds, we can strengthen the
integrity of our systems. The @command{guix challenge} command aims to
help users assess substitute servers, and to assist developers in
finding out about non-deterministic package builds (@pxref{Invoking guix
challenge}). Similarly, the @option{--check} option of @command{guix
build} allows users to check whether previously-installed substitutes
are genuine by rebuilding them locally (@pxref{build-check,
@command{guix build --check}}).
In the future, we want Guix to have support to publish and retrieve
binaries to/from other users, in a peer-to-peer fashion. If you would
like to discuss this project, join us on @email{guix-devel@@gnu.org}.
@node Packages with Multiple Outputs
@section Packages with Multiple Outputs
@cindex multiple-output packages
@cindex package outputs
Often, packages defined in Guix have a single @dfn{output}---i.e., the
source package leads exactly one directory in the store. When running
@command{guix package -i glibc}, one installs the default output of the
GNU libc package; the default output is called @code{out}, but its name
can be omitted as shown in this command. In this particular case, the
default output of @code{glibc} contains all the C header files, shared
libraries, static libraries, Info documentation, and other supporting
files.
Sometimes it is more appropriate to separate the various types of files
produced from a single source package into separate outputs. For
instance, the GLib C library (used by GTK+ and related packages)
installs more than 20 MiB of reference documentation as HTML pages.
To save space for users who do not need it, the documentation goes to a
separate output, called @code{doc}. To install the main GLib output,
which contains everything but the documentation, one would run:
@example
guix package -i glib
@end example
The command to install its documentation is:
@example
guix package -i glib:doc
@end example
Some packages install programs with different ``dependency footprints''.
For instance, the WordNet package install both command-line tools and
graphical user interfaces (GUIs). The former depend solely on the C
library, whereas the latter depend on Tcl/Tk and the underlying X
libraries. In this case, we leave the command-line tools in the default
output, whereas the GUIs are in a separate output. This allows users
who do not need the GUIs to save space. The @command{guix size} command
can help find out about such situations (@pxref{Invoking guix size}).
@command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
There are several such multiple-output packages in the GNU distribution.
Other conventional output names include @code{lib} for libraries and
possibly header files, @code{bin} for stand-alone programs, and
@code{debug} for debugging information (@pxref{Installing Debugging
Files}). The outputs of a packages are listed in the third column of
the output of @command{guix package --list-available} (@pxref{Invoking
guix package}).
@node Invoking guix gc
@section Invoking @command{guix gc}
@cindex garbage collector
Packages that are installed but not used may be @dfn{garbage-collected}.
The @command{guix gc} command allows users to explicitly run the garbage
collector to reclaim space from the @file{/gnu/store} directory. It is
the @emph{only} way to remove files from @file{/gnu/store}---removing
files or directories manually may break it beyond repair!
The garbage collector has a set of known @dfn{roots}: any file under
@file{/gnu/store} reachable from a root is considered @dfn{live} and
cannot be deleted; any other file is considered @dfn{dead} and may be
deleted. The set of garbage collector roots includes default user
profiles, and may be augmented with @command{guix build --root}, for
example (@pxref{Invoking guix build}).
Prior to running @code{guix gc --collect-garbage} to make space, it is
often useful to remove old generations from user profiles; that way, old
package builds referenced by those generations can be reclaimed. This
is achieved by running @code{guix package --delete-generations}
(@pxref{Invoking guix package}).
The @command{guix gc} command has three modes of operation: it can be
used to garbage-collect any dead files (the default), to delete specific
files (the @code{--delete} option), to print garbage-collector
information, or for more advanced queries. The garbage collection
options are as follows:
@table @code
@item --collect-garbage[=@var{min}]
@itemx -C [@var{min}]
Collect garbage---i.e., unreachable @file{/gnu/store} files and
sub-directories. This is the default operation when no option is
specified.
When @var{min} is given, stop once @var{min} bytes have been collected.
@var{min} may be a number of bytes, or it may include a unit as a
suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
(@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
When @var{min} is omitted, collect all the garbage.
@item --delete
@itemx -d
Attempt to delete all the store files and directories specified as
arguments. This fails if some of the files are not in the store, or if
they are still live.
@item --list-failures
List store items corresponding to cached build failures.
This prints nothing unless the daemon was started with
@option{--cache-failures} (@pxref{Invoking guix-daemon,
@option{--cache-failures}}).
@item --clear-failures
Remove the specified store items from the failed-build cache.
Again, this option only makes sense when the daemon is started with
@option{--cache-failures}. Otherwise, it does nothing.
@item --list-dead
Show the list of dead files and directories still present in the
store---i.e., files and directories no longer reachable from any root.
@item --list-live
Show the list of live store files and directories.
@end table
In addition, the references among existing store files can be queried:
@table @code
@item --references
@itemx --referrers
List the references (respectively, the referrers) of store files given
as arguments.
@item --requisites
@itemx -R
@cindex closure
List the requisites of the store files passed as arguments. Requisites
include the store files themselves, their references, and the references
of these, recursively. In other words, the returned list is the
@dfn{transitive closure} of the store files.
@xref{Invoking guix size}, for a tool to profile the size of an
element's closure. @xref{Invoking guix graph}, for a tool to visualize
the graph of references.
@end table
Lastly, the following options allow you to check the integrity of the
store and to control disk usage.
@table @option
@item --verify[=@var{options}]
@cindex integrity, of the store
@cindex integrity checking
Verify the integrity of the store.
By default, make sure that all the store items marked as valid in the
daemon's database actually exist in @file{/gnu/store}.
When provided, @var{options} must a comma-separated list containing one
or more of @code{contents} and @code{repair}.
When passing @option{--verify=contents}, the daemon will compute the
content hash of each store item and compare it against its hash in the
database. Hash mismatches are reported as data corruptions. Because it
traverses @emph{all the files in the store}, this command can take a
long time, especially on systems with a slow disk drive.
@cindex repairing the store
Using @option{--verify=repair} or @option{--verify=contents,repair}
causes the daemon to try to repair corrupt store items by fetching
substitutes for them (@pxref{Substitutes}). Because repairing is not
atomic, and thus potentially dangerous, it is available only to the
system administrator.
@item --optimize
@cindex deduplication
Optimize the store by hard-linking identical files---this is
@dfn{deduplication}.
The daemon performs deduplication after each successful build or archive
import, unless it was started with @code{--disable-deduplication}
(@pxref{Invoking guix-daemon, @code{--disable-deduplication}}). Thus,
this option is primarily useful when the daemon was running with
@code{--disable-deduplication}.
@end table
@node Invoking guix pull
@section Invoking @command{guix pull}
Packages are installed or upgraded to the latest version available in
the distribution currently available on your local machine. To update
that distribution, along with the Guix tools, you must run @command{guix
pull}: the command downloads the latest Guix source code and package
descriptions, and deploys it.
On completion, @command{guix package} will use packages and package
versions from this just-retrieved copy of Guix. Not only that, but all
the Guix commands and Scheme modules will also be taken from that latest
version. New @command{guix} sub-commands added by the update also
become available@footnote{Under the hood, @command{guix pull} updates
the @file{~/.config/guix/latest} symbolic link to point to the latest
Guix, and the @command{guix} command loads code from there.}.
The @command{guix pull} command is usually invoked with no arguments,
but it supports the following options:
@table @code
@item --verbose
Produce verbose output, writing build logs to the standard error output.
@item --url=@var{url}
Download the source tarball of Guix from @var{url}.
By default, the tarball is taken from its canonical address at
@code{gnu.org}, for the stable branch of Guix.
@item --bootstrap
Use the bootstrap Guile to build the latest Guix. This option is only
useful to Guix developers.
@end table
@node Invoking guix archive
@section Invoking @command{guix archive}
The @command{guix archive} command allows users to @dfn{export} files
from the store into a single archive, and to later @dfn{import} them.
In particular, it allows store files to be transferred from one machine
to another machine's store. For example, to transfer the @code{emacs}
package to a machine connected over SSH, one would run:
@example
guix archive --export -r emacs | ssh the-machine guix archive --import
@end example
@noindent
Similarly, a complete user profile may be transferred from one machine
to another like this:
@example
guix archive --export -r $(readlink -f ~/.guix-profile) | \
ssh the-machine guix-archive --import
@end example
@noindent
However, note that, in both examples, all of @code{emacs} and the
profile as well as all of their dependencies are transferred (due to
@code{-r}), regardless of what is already available in the target
machine's store. The @code{--missing} option can help figure out which
items are missing from the target's store.
Archives are stored in the ``Nix archive'' or ``Nar'' format, which is
comparable in spirit to `tar', but with a few noteworthy differences
that make it more appropriate for our purposes. First, rather than
recording all Unix meta-data for each file, the Nar format only mentions
the file type (regular, directory, or symbolic link); Unix permissions
and owner/group are dismissed. Second, the order in which directory
entries are stored always follows the order of file names according to
the C locale collation order. This makes archive production fully
deterministic.
When exporting, the daemon digitally signs the contents of the archive,
and that digital signature is appended. When importing, the daemon
verifies the signature and rejects the import in case of an invalid
signature or if the signing key is not authorized.
@c FIXME: Add xref to daemon doc about signatures.
The main options are:
@table @code
@item --export
Export the specified store files or packages (see below.) Write the
resulting archive to the standard output.
Dependencies are @emph{not} included in the output, unless
@code{--recursive} is passed.
@item -r
@itemx --recursive
When combined with @code{--export}, this instructs @command{guix
archive} to include dependencies of the given items in the archive.
Thus, the resulting archive is self-contained: it contains the closure
of the exported store items.
@item --import
Read an archive from the standard input, and import the files listed
therein into the store. Abort if the archive has an invalid digital
signature, or if it is signed by a public key not among the authorized
keys (see @code{--authorize} below.)
@item --missing
Read a list of store file names from the standard input, one per line,
and write on the standard output the subset of these files missing from
the store.
@item --generate-key[=@var{parameters}]
@cindex signing, archives
Generate a new key pair for the daemons. This is a prerequisite before
archives can be exported with @code{--export}. Note that this operation
usually takes time, because it needs to gather enough entropy to
generate the key pair.
The generated key pair is typically stored under @file{/etc/guix}, in
@file{signing-key.pub} (public key) and @file{signing-key.sec} (private
key, which must be kept secret.) When @var{parameters} is omitted,
an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
versions before 1.6.0, it is a 4096-bit RSA key.
Alternately, @var{parameters} can specify
@code{genkey} parameters suitable for Libgcrypt (@pxref{General
public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
Libgcrypt Reference Manual}).
@item --authorize
@cindex authorizing, archives
Authorize imports signed by the public key passed on standard input.
The public key must be in ``s-expression advanced format''---i.e., the
same format as the @file{signing-key.pub} file.
The list of authorized keys is kept in the human-editable file
@file{/etc/guix/acl}. The file contains
@url{http://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
s-expressions''} and is structured as an access-control list in the
@url{http://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
(SPKI)}.
@item --extract=@var{directory}
@itemx -x @var{directory}
Read a single-item archive as served by substitute servers
(@pxref{Substitutes}) and extract it to @var{directory}. This is a
low-level operation needed in only very narrow use cases; see below.
For example, the following command extracts the substitute for Emacs
served by @code{hydra.gnu.org} to @file{/tmp/emacs}:
@example
$ wget -O - \
http://hydra.gnu.org/nar/@dots{}-emacs-24.5 \
| bunzip2 | guix archive -x /tmp/emacs
@end example
Single-item archives are different from multiple-item archives produced
by @command{guix archive --export}; they contain a single store item,
and they do @emph{not} embed a signature. Thus this operation does
@emph{no} signature verification and its output should be considered
unsafe.
The primary purpose of this operation is to facilitate inspection of
archive contents coming from possibly untrusted substitute servers.
@end table
To export store files as an archive to the standard output, run:
@example
guix archive --export @var{options} @var{specifications}...
@end example
@var{specifications} may be either store file names or package
specifications, as for @command{guix package} (@pxref{Invoking guix
package}). For instance, the following command creates an archive
containing the @code{gui} output of the @code{git} package and the main
output of @code{emacs}:
@example
guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
@end example
If the specified packages are not built yet, @command{guix archive}
automatically builds them. The build process may be controlled with the
same options that can be passed to the @command{guix build} command
(@pxref{Invoking guix build, common build options}).
@c *********************************************************************
@include emacs.texi
@c *********************************************************************
@node Programming Interface
@chapter Programming Interface
GNU Guix provides several Scheme programming interfaces (APIs) to
define, build, and query packages. The first interface allows users to
write high-level package definitions. These definitions refer to
familiar packaging concepts, such as the name and version of a package,
its build system, and its dependencies. These definitions can then be
turned into concrete build actions.
Build actions are performed by the Guix daemon, on behalf of users. In a
standard setup, the daemon has write access to the store---the
@file{/gnu/store} directory---whereas users do not. The recommended
setup also has the daemon perform builds in chroots, under a specific
build users, to minimize interference with the rest of the system.
@cindex derivation
Lower-level APIs are available to interact with the daemon and the
store. To instruct the daemon to perform a build action, users actually
provide it with a @dfn{derivation}. A derivation is a low-level
representation of the build actions to be taken, and the environment in
which they should occur---derivations are to package definitions what
assembly is to C programs. The term ``derivation'' comes from the fact
that build results @emph{derive} from them.
This chapter describes all these APIs in turn, starting from high-level
package definitions.
@menu
* Defining Packages:: Defining new packages.
* Build Systems:: Specifying how packages are built.
* The Store:: Manipulating the package store.
* Derivations:: Low-level interface to package derivations.
* The Store Monad:: Purely functional interface to the store.
* G-Expressions:: Manipulating build expressions.
@end menu
@node Defining Packages
@section Defining Packages
The high-level interface to package definitions is implemented in the
@code{(guix packages)} and @code{(guix build-system)} modules. As an
example, the package definition, or @dfn{recipe}, for the GNU Hello
package looks like this:
@example
(define-module (gnu packages hello)
#:use-module (guix packages)
#:use-module (guix download)
#:use-module (guix build-system gnu)
#:use-module (guix licenses)
#:use-module (gnu packages gawk))
(define-public hello
(package
(name "hello")
(version "2.10")
(source (origin
(method url-fetch)
(uri (string-append "mirror://gnu/hello/hello-" version
".tar.gz"))
(sha256
(base32
"0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
(build-system gnu-build-system)
(arguments `(#:configure-flags '("--enable-silent-rules")))
(inputs `(("gawk" ,gawk)))
(synopsis "Hello, GNU world: An example GNU package")
(description "Guess what GNU Hello prints!")
(home-page "http://www.gnu.org/software/hello/")
(license gpl3+)))
@end example
@noindent
Without being a Scheme expert, the reader may have guessed the meaning
of the various fields here. This expression binds variable @code{hello}
to a @code{<package>} object, which is essentially a record
(@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
This package object can be inspected using procedures found in the
@code{(guix packages)} module; for instance, @code{(package-name hello)}
returns---surprise!---@code{"hello"}.
With luck, you may be able to import part or all of the definition of
the package you are interested in from another repository, using the
@code{guix import} command (@pxref{Invoking guix import}).
In the example above, @var{hello} is defined into a module of its own,
@code{(gnu packages hello)}. Technically, this is not strictly
necessary, but it is convenient to do so: all the packages defined in
modules under @code{(gnu packages @dots{})} are automatically known to
the command-line tools (@pxref{Package Modules}).
There are a few points worth noting in the above package definition:
@itemize
@item
The @code{source} field of the package is an @code{<origin>} object
(@pxref{origin Reference}, for the complete reference).
Here, the @code{url-fetch} method from @code{(guix download)} is used,
meaning that the source is a file to be downloaded over FTP or HTTP.
The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
the GNU mirrors defined in @code{(guix download)}.
The @code{sha256} field specifies the expected SHA256 hash of the file
being downloaded. It is mandatory, and allows Guix to check the
integrity of the file. The @code{(base32 @dots{})} form introduces the
base32 representation of the hash. You can obtain this information with
@code{guix download} (@pxref{Invoking guix download}) and @code{guix
hash} (@pxref{Invoking guix hash}).
@cindex patches
When needed, the @code{origin} form can also have a @code{patches} field
listing patches to be applied, and a @code{snippet} field giving a
Scheme expression to modify the source code.
@item
@cindex GNU Build System
The @code{build-system} field specifies the procedure to build the
package (@pxref{Build Systems}). Here, @var{gnu-build-system}
represents the familiar GNU Build System, where packages may be
configured, built, and installed with the usual @code{./configure &&
make && make check && make install} command sequence.
@item
The @code{arguments} field specifies options for the build system
(@pxref{Build Systems}). Here it is interpreted by
@var{gnu-build-system} as a request run @file{configure} with the
@code{--enable-silent-rules} flag.
@item
The @code{inputs} field specifies inputs to the build process---i.e.,
build-time or run-time dependencies of the package. Here, we define an
input called @code{"gawk"} whose value is that of the @var{gawk}
variable; @var{gawk} is itself bound to a @code{<package>} object.
Note that GCC, Coreutils, Bash, and other essential tools do not need to
be specified as inputs here. Instead, @var{gnu-build-system} takes care
of ensuring that they are present (@pxref{Build Systems}).
However, any other dependencies need to be specified in the
@code{inputs} field. Any dependency not specified here will simply be
unavailable to the build process, possibly leading to a build failure.
@end itemize
@xref{package Reference}, for a full description of possible fields.
Once a package definition is in place, the
package may actually be built using the @code{guix build} command-line
tool (@pxref{Invoking guix build}). You can easily jump back to the
package definition using the @command{guix edit} command
(@pxref{Invoking guix edit}).
@xref{Packaging Guidelines}, for
more information on how to test package definitions, and
@ref{Invoking guix lint}, for information on how to check a definition
for style conformance.
Eventually, updating the package definition to a new upstream version
can be partly automated by the @command{guix refresh} command
(@pxref{Invoking guix refresh}).
Behind the scenes, a derivation corresponding to the @code{<package>}
object is first computed by the @code{package-derivation} procedure.
That derivation is stored in a @code{.drv} file under @file{/gnu/store}.
The build actions it prescribes may then be realized by using the
@code{build-derivations} procedure (@pxref{The Store}).
@deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
Return the @code{<derivation>} object of @var{package} for @var{system}
(@pxref{Derivations}).
@var{package} must be a valid @code{<package>} object, and @var{system}
must be a string denoting the target system type---e.g.,
@code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
must be a connection to the daemon, which operates on the store
(@pxref{The Store}).
@end deffn
@noindent
@cindex cross-compilation
Similarly, it is possible to compute a derivation that cross-builds a
package for some other system:
@deffn {Scheme Procedure} package-cross-derivation @var{store} @
@var{package} @var{target} [@var{system}]
Return the @code{<derivation>} object of @var{package} cross-built from
@var{system} to @var{target}.
@var{target} must be a valid GNU triplet denoting the target hardware
and operating system, such as @code{"mips64el-linux-gnu"}
(@pxref{Configuration Names, GNU configuration triplets,, configure, GNU
Configure and Build System}).
@end deffn
@menu
* package Reference :: The package data type.
* origin Reference:: The origin data type.
@end menu
@node package Reference
@subsection @code{package} Reference
This section summarizes all the options available in @code{package}
declarations (@pxref{Defining Packages}).
@deftp {Data Type} package
This is the data type representing a package recipe.
@table @asis
@item @code{name}
The name of the package, as a string.
@item @code{version}
The version of the package, as a string.
@item @code{source}
An origin object telling how the source code for the package should be
acquired (@pxref{origin Reference}).
@item @code{build-system}
The build system that should be used to build the package (@pxref{Build
Systems}).
@item @code{arguments} (default: @code{'()})
The arguments that should be passed to the build system. This is a
list, typically containing sequential keyword-value pairs.
@item @code{inputs} (default: @code{'()})
@itemx @code{native-inputs} (default: @code{'()})
@itemx @code{propagated-inputs} (default: @code{'()})
@cindex inputs, of packages
These fields list dependencies of the package. Each one is a list of
tuples, where each tuple has a label for the input (a string) as its
first element, a package, origin, or derivation as its second element,
and optionally the name of the output thereof that should be used, which
defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
more on package outputs). For example, the list below specifies 3
inputs:
@example
`(("libffi" ,libffi)
("libunistring" ,libunistring)
("glib:bin" ,glib "bin")) ;the "bin" output of Glib
@end example
@cindex cross compilation, package dependencies
The distinction between @code{native-inputs} and @code{inputs} is
necessary when considering cross-compilation. When cross-compiling,
dependencies listed in @code{inputs} are built for the @emph{target}
architecture; conversely, dependencies listed in @code{native-inputs}
are built for the architecture of the @emph{build} machine.
@code{native-inputs} is typically where you would list tools needed at
build time but not at run time, such as Autoconf, Automake, pkg-config,
Gettext, or Bison. @command{guix lint} can report likely mistakes in
this area (@pxref{Invoking guix lint}).
@anchor{package-propagated-inputs}
Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
specified packages will be force-installed alongside the package they
belong to (@pxref{package-cmd-propagated-inputs, @command{guix
package}}, for information on how @command{guix package} deals with
propagated inputs.)
For example this is necessary when a C/C++ library needs headers of
another library to compile, or when a pkg-config file refers to another
one @i{via} its @code{Requires} field.
Another example where @code{propagated-inputs} is useful is for
languages that lack a facility to record the run-time search path akin
to ELF's @code{RUNPATH}; this includes Guile, Python, Perl, GHC, and
more. To ensure that libraries written in those languages can find
library code they depend on at run time, run-time dependencies must be
listed in @code{propagated-inputs} rather than @code{inputs}.
@item @code{self-native-input?} (default: @code{#f})
This is a Boolean field telling whether the package should use itself as
a native input when cross-compiling.
@item @code{outputs} (default: @code{'("out")})
The list of output names of the package. @xref{Packages with Multiple
Outputs}, for typical uses of additional outputs.
@item @code{native-search-paths} (default: @code{'()})
@itemx @code{search-paths} (default: @code{'()})
A list of @code{search-path-specification} objects describing
search-path environment variables honored by the package.
@item @code{replacement} (default: @code{#f})
This must either @code{#f} or a package object that will be used as a
@dfn{replacement} for this package. @xref{Security Updates, grafts},
for details.
@item @code{synopsis}
A one-line description of the package.
@item @code{description}
A more elaborate description of the package.
@item @code{license}
The license of the package; a value from @code{(guix licenses)}.
@item @code{home-page}
The URL to the home-page of the package, as a string.
@item @code{supported-systems} (default: @var{%supported-systems})
The list of systems supported by the package, as strings of the form
@code{architecture-kernel}, for example @code{"x86_64-linux"}.
@item @code{maintainers} (default: @code{'()})
The list of maintainers of the package, as @code{maintainer} objects.
@item @code{location} (default: source location of the @code{package} form)
The source location of the package. It's useful to override this when
inheriting from another package, in which case this field is not
automatically corrected.
@end table
@end deftp
@node origin Reference
@subsection @code{origin} Reference
This section summarizes all the options available in @code{origin}
declarations (@pxref{Defining Packages}).
@deftp {Data Type} origin
This is the data type representing a source code origin.
@table @asis
@item @code{uri}
An object containing the URI of the source. The object type depends on
the @code{method} (see below). For example, when using the
@var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
values are: a URL represented as a string, or a list thereof.
@item @code{method}
A procedure that will handle the URI.
Examples include:
@table @asis
@item @var{url-fetch} from @code{(guix download)}
download a file the HTTP, HTTPS, or FTP URL specified in the
@code{uri} field;
@item @var{git-fetch} from @code{(guix git-download)}
clone the Git version control repository, and check out the revision
specified in the @code{uri} field as a @code{git-reference} object; a
@code{git-reference} looks like this:
@example
(git-reference
(url "git://git.debian.org/git/pkg-shadow/shadow")
(commit "v4.1.5.1"))
@end example
@end table
@item @code{sha256}
A bytevector containing the SHA-256 hash of the source. Typically the
@code{base32} form is used here to generate the bytevector from a
base-32 string.
@item @code{file-name} (default: @code{#f})
The file name under which the source code should be saved. When this is
@code{#f}, a sensible default value will be used in most cases. In case
the source is fetched from a URL, the file name from the URL will be
used. For version control checkouts, it's recommended to provide the
file name explicitly because the default is not very descriptive.
@item @code{patches} (default: @code{'()})
A list of file names containing patches to be applied to the source.
@item @code{snippet} (default: @code{#f})
A quoted piece of code that will be run in the source directory to make
any modifications, which is sometimes more convenient than a patch.
@item @code{patch-flags} (default: @code{'("-p1")})
A list of command-line flags that should be passed to the @code{patch}
command.
@item @code{patch-inputs} (default: @code{#f})
Input packages or derivations to the patching process. When this is
@code{#f}, the usual set of inputs necessary for patching are provided,
such as GNU@tie{}Patch.
@item @code{modules} (default: @code{'()})
A list of Guile modules that should be loaded during the patching
process and while running the code in the @code{snippet} field.
@item @code{imported-modules} (default: @code{'()})
The list of Guile modules to import in the patch derivation, for use by
the @code{snippet}.
@item @code{patch-guile} (default: @code{#f})
The Guile package that should be used in the patching process. When
this is @code{#f}, a sensible default is used.
@end table
@end deftp
@node Build Systems
@section Build Systems
@cindex build system
Each package definition specifies a @dfn{build system} and arguments for
that build system (@pxref{Defining Packages}). This @code{build-system}
field represents the build procedure of the package, as well implicit
dependencies of that build procedure.
Build systems are @code{<build-system>} objects. The interface to
create and manipulate them is provided by the @code{(guix build-system)}
module, and actual build systems are exported by specific modules.
@cindex bag (low-level package representation)
Under the hood, build systems first compile package objects to
@dfn{bags}. A @dfn{bag} is like a package, but with less
ornamentation---in other words, a bag is a lower-level representation of
a package, which includes all the inputs of that package, including some
that were implicitly added by the build system. This intermediate
representation is then compiled to a derivation (@pxref{Derivations}).
Build systems accept an optional list of @dfn{arguments}. In package
definitions, these are passed @i{via} the @code{arguments} field
(@pxref{Defining Packages}). They are typically keyword arguments
(@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
Guile Reference Manual}). The value of these arguments is usually
evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
by the daemon (@pxref{Derivations}).
The main build system is @var{gnu-build-system}, which implements the
standard build procedure for GNU packages and many other packages. It
is provided by the @code{(guix build-system gnu)} module.
@defvr {Scheme Variable} gnu-build-system
@var{gnu-build-system} represents the GNU Build System, and variants
thereof (@pxref{Configuration, configuration and makefile conventions,,
standards, GNU Coding Standards}).
@cindex build phases
In a nutshell, packages using it configured, built, and installed with
the usual @code{./configure && make && make check && make install}
command sequence. In practice, a few additional steps are often needed.
All these steps are split up in separate @dfn{phases},
notably@footnote{Please see the @code{(guix build gnu-build-system)}
modules for more details about the build phases.}:
@table @code
@item unpack
Unpack the source tarball, and change the current directory to the
extracted source tree. If the source is actually a directory, copy it
to the build tree, and enter that directory.
@item patch-source-shebangs
Patch shebangs encountered in source files so they refer to the right
store file names. For instance, this changes @code{#!/bin/sh} to
@code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
@item configure
Run the @file{configure} script with a number of default options, such
as @code{--prefix=/gnu/store/@dots{}}, as well as the options specified
by the @code{#:configure-flags} argument.
@item build
Run @code{make} with the list of flags specified with
@code{#:make-flags}. If the @code{#:parallel-build?} argument is true
(the default), build with @code{make -j}.
@item check
Run @code{make check}, or some other target specified with
@code{#:test-target}, unless @code{#:tests? #f} is passed. If the
@code{#:parallel-tests?} argument is true (the default), run @code{make
check -j}.
@item install
Run @code{make install} with the flags listed in @code{#:make-flags}.
@item patch-shebangs
Patch shebangs on the installed executable files.
@item strip
Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
is false), copying them to the @code{debug} output when available
(@pxref{Installing Debugging Files}).
@end table
@vindex %standard-phases
The build-side module @code{(guix build gnu-build-system)} defines
@var{%standard-phases} as the default list of build phases.
@var{%standard-phases} is a list of symbol/procedure pairs, where the
procedure implements the actual phase.
The list of phases used for a particular package can be changed with the
@code{#:phases} parameter. For instance, passing:
@example
#:phases (alist-delete 'configure %standard-phases)
@end example
means that all the phases described above will be used, except the
@code{configure} phase.
In addition, this build system ensures that the ``standard'' environment
for GNU packages is available. This includes tools such as GCC, libc,
Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
build-system gnu)} module for a complete list.) We call these the
@dfn{implicit inputs} of a package, because package definitions don't
have to mention them.
@end defvr
Other @code{<build-system>} objects are defined to support other
conventions and tools used by free software packages. They inherit most
of @var{gnu-build-system}, and differ mainly in the set of inputs
implicitly added to the build process, and in the list of phases
executed. Some of these build systems are listed below.
@defvr {Scheme Variable} cmake-build-system
This variable is exported by @code{(guix build-system cmake)}. It
implements the build procedure for packages using the
@url{http://www.cmake.org, CMake build tool}.
It automatically adds the @code{cmake} package to the set of inputs.
Which package is used can be specified with the @code{#:cmake}
parameter.
The @code{#:configure-flags} parameter is taken as a list of flags
passed to the @command{cmake} command. The @code{#:build-type}
parameter specifies in abstract terms the flags passed to the compiler;
it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
debugging information''), which roughly means that code is compiled with
@code{-O2 -g}, as is the case for Autoconf-based packages by default.
@end defvr
@defvr {Scheme Variable} glib-or-gtk-build-system
This variable is exported by @code{(guix build-system glib-or-gtk)}. It
is intended for use with packages making use of GLib or GTK+.
This build system adds the following two phases to the ones defined by
@var{gnu-build-system}:
@table @code
@item glib-or-gtk-wrap
The phase @code{glib-or-gtk-wrap} ensures that programs found under
@file{bin/} are able to find GLib's ``schemas'' and
@uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
modules}. This is achieved by wrapping the programs in launch scripts
that appropriately set the @code{XDG_DATA_DIRS} and @code{GTK_PATH}
environment variables.
It is possible to exclude specific package outputs from that wrapping
process by listing their names in the
@code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
when an output is known not to contain any GLib or GTK+ binaries, and
where wrapping would gratuitously add a dependency of that output on
GLib and GTK+.
@item glib-or-gtk-compile-schemas
The phase @code{glib-or-gtk-compile-schemas} makes sure that all GLib's
@uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
GSettings schemas} are compiled. Compilation is performed by the
@command{glib-compile-schemas} program. It is provided by the package
@code{glib:bin} which is automatically imported by the build system.
The @code{glib} package providing @command{glib-compile-schemas} can be
specified with the @code{#:glib} parameter.
@end table
Both phases are executed after the @code{install} phase.
@end defvr
@defvr {Scheme Variable} python-build-system
This variable is exported by @code{(guix build-system python)}. It
implements the more or less standard build procedure used by Python
packages, which consists in running @code{python setup.py build} and
then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
For packages that install stand-alone Python programs under @code{bin/},
it takes care of wrapping these programs so their @code{PYTHONPATH}
environment variable points to all the Python libraries they depend on.
Which Python package is used can be specified with the @code{#:python}
parameter.
@end defvr
@defvr {Scheme Variable} perl-build-system
This variable is exported by @code{(guix build-system perl)}. It
implements the standard build procedure for Perl packages, which either
consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
followed by @code{Build} and @code{Build install}; or in running
@code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
@code{make} and @code{make install}; depending on which of
@code{Build.PL} or @code{Makefile.PL} is present in the package
distribution. Preference is given to the former if both @code{Build.PL}
and @code{Makefile.PL} exist in the package distribution. This
preference can be reversed by specifying @code{#t} for the
@code{#:make-maker?} parameter.
The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
passes flags specified by the @code{#:make-maker-flags} or
@code{#:module-build-flags} parameter, respectively.
Which Perl package is used can be specified with @code{#:perl}.
@end defvr
@defvr {Scheme Variable} r-build-system
This variable is exported by @code{(guix build-system r)}. It
implements the build procedure used by @uref{http://r-project.org, R}
packages, which essentially is little more than running @code{R CMD
INSTALL --library=/gnu/store/@dots{}} in an environment where
@code{R_LIBS_SITE} contains the paths to all R package inputs. Tests
are run after installation using the R function
@code{tools::testInstalledPackage}.
@end defvr
@defvr {Scheme Variable} ruby-build-system
This variable is exported by @code{(guix build-system ruby)}. It
implements the RubyGems build procedure used by Ruby packages, which
involves running @code{gem build} followed by @code{gem install}.
The @code{source} field of a package that uses this build system
typically references a gem archive, since this is the format that Ruby
developers use when releasing their software. The build system unpacks
the gem archive, potentially patches the source, runs the test suite,
repackages the gem, and installs it. Additionally, directories and
tarballs may be referenced to allow building unreleased gems from Git or
a traditional source release tarball.
Which Ruby package is used can be specified with the @code{#:ruby}
parameter. A list of additional flags to be passed to the @command{gem}
command can be specified with the @code{#:gem-flags} parameter.
@end defvr
@defvr {Scheme Variable} waf-build-system
This variable is exported by @code{(guix build-system waf)}. It
implements a build procedure around the @code{waf} script. The common
phases---@code{configure}, @code{build}, and @code{install}---are
implemented by passing their names as arguments to the @code{waf}
script.
The @code{waf} script is executed by the Python interpreter. Which
Python package is used to run the script can be specified with the
@code{#:python} parameter.
@end defvr
@defvr {Scheme Variable} haskell-build-system
This variable is exported by @code{(guix build-system haskell)}. It
implements the Cabal build procedure used by Haskell packages, which
involves running @code{runhaskell Setup.hs configure
--prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
Instead of installing the package by running @code{runhaskell Setup.hs
install}, to avoid trying to register libraries in the read-only
compiler store directory, the build system uses @code{runhaskell
Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
addition, the build system generates the package documentation by
running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
is passed. Optional Haddock parameters can be passed with the help of
the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
not found, the build system looks for @code{Setup.lhs} instead.
Which Haskell compiler is used can be specified with the @code{#:haskell}
parameter which defaults to @code{ghc}.
@end defvr
@defvr {Scheme Variable} emacs-build-system
This variable is exported by @code{(guix build-system emacs)}. It
implements an installation procedure similar to the one of Emacs' own
packaging system (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
It first creates the @code{@var{package}-autoloads.el} file, then it
byte compiles all Emacs Lisp files. Differently from the Emacs
packaging system, the Info documentation files are moved to the standard
documentation directory and the @file{dir} file is deleted. Each
package is installed in its own directory under
@file{share/emacs/site-lisp/guix.d}.
@end defvr
Lastly, for packages that do not need anything as sophisticated, a
``trivial'' build system is provided. It is trivial in the sense that
it provides basically no support: it does not pull any implicit inputs,
and does not have a notion of build phases.
@defvr {Scheme Variable} trivial-build-system
This variable is exported by @code{(guix build-system trivial)}.
This build system requires a @code{#:builder} argument. This argument
must be a Scheme expression that builds the package's output(s)---as
with @code{build-expression->derivation} (@pxref{Derivations,
@code{build-expression->derivation}}).
@end defvr
@node The Store
@section The Store
@cindex store
@cindex store paths
Conceptually, the @dfn{store} is where derivations that have been
successfully built are stored---by default, under @file{/gnu/store}.
Sub-directories in the store are referred to as @dfn{store paths}. The
store has an associated database that contains information such as the
store paths referred to by each store path, and the list of @emph{valid}
store paths---paths that result from a successful build.
The store is always accessed by the daemon on behalf of its clients
(@pxref{Invoking guix-daemon}). To manipulate the store, clients
connect to the daemon over a Unix-domain socket, send it requests, and
read the result---these are remote procedure calls, or RPCs.
The @code{(guix store)} module provides procedures to connect to the
daemon, and to perform RPCs. These are described below.
@deffn {Scheme Procedure} open-connection [@var{file}] [#:reserve-space? #t]
Connect to the daemon over the Unix-domain socket at @var{file}. When
@var{reserve-space?} is true, instruct it to reserve a little bit of
extra space on the file system so that the garbage collector can still
operate, should the disk become full. Return a server object.
@var{file} defaults to @var{%default-socket-path}, which is the normal
location given the options that were passed to @command{configure}.
@end deffn
@deffn {Scheme Procedure} close-connection @var{server}
Close the connection to @var{server}.
@end deffn
@defvr {Scheme Variable} current-build-output-port
This variable is bound to a SRFI-39 parameter, which refers to the port
where build and error logs sent by the daemon should be written.
@end defvr
Procedures that make RPCs all take a server object as their first
argument.
@deffn {Scheme Procedure} valid-path? @var{server} @var{path}
Return @code{#t} when @var{path} is a valid store path.
@end deffn
@deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
Add @var{text} under file @var{name} in the store, and return its store
path. @var{references} is the list of store paths referred to by the
resulting store path.
@end deffn
@deffn {Scheme Procedure} build-derivations @var{server} @var{derivations}
Build @var{derivations} (a list of @code{<derivation>} objects or
derivation paths), and return when the worker is done building them.
Return @code{#t} on success.
@end deffn
Note that the @code{(guix monads)} module provides a monad as well as
monadic versions of the above procedures, with the goal of making it
more convenient to work with code that accesses the store (@pxref{The
Store Monad}).
@c FIXME
@i{This section is currently incomplete.}
@node Derivations
@section Derivations
@cindex derivations
Low-level build actions and the environment in which they are performed
are represented by @dfn{derivations}. A derivation contain the
following pieces of information:
@itemize
@item
The outputs of the derivation---derivations produce at least one file or
directory in the store, but may produce more.
@item
The inputs of the derivations, which may be other derivations or plain
files in the store (patches, build scripts, etc.)
@item
The system type targeted by the derivation---e.g., @code{x86_64-linux}.
@item
The file name of a build script in the store, along with the arguments
to be passed.
@item
A list of environment variables to be defined.
@end itemize
@cindex derivation path
Derivations allow clients of the daemon to communicate build actions to
the store. They exist in two forms: as an in-memory representation,
both on the client- and daemon-side, and as files in the store whose
name end in @code{.drv}---these files are referred to as @dfn{derivation
paths}. Derivations paths can be passed to the @code{build-derivations}
procedure to perform the build actions they prescribe (@pxref{The
Store}).
The @code{(guix derivations)} module provides a representation of
derivations as Scheme objects, along with procedures to create and
otherwise manipulate derivations. The lowest-level primitive to create
a derivation is the @code{derivation} procedure:
@deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
@var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
[#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
[#:system (%current-system)] [#:references-graphs #f] @
[#:allowed-references #f] [#:leaked-env-vars #f] [#:local-build? #f] @
[#:substitutable? #t]
Build a derivation with the given arguments, and return the resulting
@code{<derivation>} object.
When @var{hash} and @var{hash-algo} are given, a
@dfn{fixed-output derivation} is created---i.e., one whose result is
known in advance, such as a file download. If, in addition,
@var{recursive?} is true, then that fixed output may be an executable
file or a directory and @var{hash} must be the hash of an archive
containing this output.
When @var{references-graphs} is true, it must be a list of file
name/store path pairs. In that case, the reference graph of each store
path is exported in the build environment in the corresponding file, in
a simple text format.
When @var{allowed-references} is true, it must be a list of store items
or outputs that the derivation's output may refer to.
When @var{leaked-env-vars} is true, it must be a list of strings
denoting environment variables that are allowed to ``leak'' from the
daemon's environment to the build environment. This is only applicable
to fixed-output derivations---i.e., when @var{hash} is true. The main
use is to allow variables such as @code{http_proxy} to be passed to
derivations that download files.
When @var{local-build?} is true, declare that the derivation is not a
good candidate for offloading and should rather be built locally
(@pxref{Daemon Offload Setup}). This is the case for small derivations
where the costs of data transfers would outweigh the benefits.
When @var{substitutable?} is false, declare that substitutes of the
derivation's output should not be used (@pxref{Substitutes}). This is
useful, for instance, when building packages that capture details of the
host CPU instruction set.
@end deffn
@noindent
Here's an example with a shell script as its builder, assuming
@var{store} is an open connection to the daemon, and @var{bash} points
to a Bash executable in the store:
@lisp
(use-modules (guix utils)
(guix store)
(guix derivations))
(let ((builder ; add the Bash script to the store
(add-text-to-store store "my-builder.sh"
"echo hello world > $out\n" '())))
(derivation store "foo"
bash `("-e" ,builder)
#:inputs `((,bash) (,builder))
#:env-vars '(("HOME" . "/homeless"))))
@result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
@end lisp
As can be guessed, this primitive is cumbersome to use directly. A
better approach is to write build scripts in Scheme, of course! The
best course of action for that is to write the build code as a
``G-expression'', and to pass it to @code{gexp->derivation}. For more
information, @pxref{G-Expressions}.
Once upon a time, @code{gexp->derivation} did not exist and constructing
derivations with build code written in Scheme was achieved with
@code{build-expression->derivation}, documented below. This procedure
is now deprecated in favor of the much nicer @code{gexp->derivation}.
@deffn {Scheme Procedure} build-expression->derivation @var{store} @
@var{name} @var{exp} @
[#:system (%current-system)] [#:inputs '()] @
[#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
[#:recursive? #f] [#:env-vars '()] [#:modules '()] @
[#:references-graphs #f] [#:allowed-references #f] @
[#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
Return a derivation that executes Scheme expression @var{exp} as a
builder for derivation @var{name}. @var{inputs} must be a list of
@code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
@code{"out"} is assumed. @var{modules} is a list of names of Guile
modules from the current search path to be copied in the store,
compiled, and made available in the load path during the execution of
@var{exp}---e.g., @code{((guix build utils) (guix build
gnu-build-system))}.
@var{exp} is evaluated in an environment where @code{%outputs} is bound
to a list of output/path pairs, and where @code{%build-inputs} is bound
to a list of string/output-path pairs made from @var{inputs}.
Optionally, @var{env-vars} is a list of string pairs specifying the name
and value of environment variables visible to the builder. The builder
terminates by passing the result of @var{exp} to @code{exit}; thus, when
@var{exp} returns @code{#f}, the build is considered to have failed.
@var{exp} is built using @var{guile-for-build} (a derivation). When
@var{guile-for-build} is omitted or is @code{#f}, the value of the
@code{%guile-for-build} fluid is used instead.
See the @code{derivation} procedure for the meaning of
@var{references-graphs}, @var{allowed-references}, @var{local-build?},
and @var{substitutable?}.
@end deffn
@noindent
Here's an example of a single-output derivation that creates a directory
containing one file:
@lisp
(let ((builder '(let ((out (assoc-ref %outputs "out")))
(mkdir out) ; create /gnu/store/@dots{}-goo
(call-with-output-file (string-append out "/test")
(lambda (p)
(display '(hello guix) p))))))
(build-expression->derivation store "goo" builder))
@result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
@end lisp
@node The Store Monad
@section The Store Monad
@cindex monad
The procedures that operate on the store described in the previous
sections all take an open connection to the build daemon as their first
argument. Although the underlying model is functional, they either have
side effects or depend on the current state of the store.
The former is inconvenient: the connection to the build daemon has to be
carried around in all those functions, making it impossible to compose
functions that do not take that parameter with functions that do. The
latter can be problematic: since store operations have side effects
and/or depend on external state, they have to be properly sequenced.
@cindex monadic values
@cindex monadic functions
This is where the @code{(guix monads)} module comes in. This module
provides a framework for working with @dfn{monads}, and a particularly
useful monad for our uses, the @dfn{store monad}. Monads are a
construct that allows two things: associating ``context'' with values
(in our case, the context is the store), and building sequences of
computations (here computations include accesses to the store.) Values
in a monad---values that carry this additional context---are called
@dfn{monadic values}; procedures that return such values are called
@dfn{monadic procedures}.
Consider this ``normal'' procedure:
@example
(define (sh-symlink store)
;; Return a derivation that symlinks the 'bash' executable.
(let* ((drv (package-derivation store bash))
(out (derivation->output-path drv))
(sh (string-append out "/bin/bash")))
(build-expression->derivation store "sh"
`(symlink ,sh %output))))
@end example
Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
as a monadic function:
@example
(define (sh-symlink)
;; Same, but return a monadic value.
(mlet %store-monad ((drv (package->derivation bash)))
(gexp->derivation "sh"
#~(symlink (string-append #$drv "/bin/bash")
#$output))))
@end example
There several things to note in the second version: the @code{store}
parameter is now implicit and is ``threaded'' in the calls to the
@code{package->derivation} and @code{gexp->derivation} monadic
procedures, and the monadic value returned by @code{package->derivation}
is @dfn{bound} using @code{mlet} instead of plain @code{let}.
As it turns out, the call to @code{package->derivation} can even be
omitted since it will take place implicitly, as we will see later
(@pxref{G-Expressions}):
@example
(define (sh-symlink)
(gexp->derivation "sh"
#~(symlink (string-append #$bash "/bin/bash")
#$output)))
@end example
@c See
@c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
@c for the funny quote.
Calling the monadic @code{sh-symlink} has no effect. As someone once
said, ``you exit a monad like you exit a building on fire: by running''.
So, to exit the monad and get the desired effect, one must use
@code{run-with-store}:
@example
(run-with-store (open-connection) (sh-symlink))
@result{} /gnu/store/...-sh-symlink
@end example
Note that the @code{(guix monad-repl)} module extends Guile's REPL with
new ``meta-commands'' to make it easier to deal with monadic procedures:
@code{run-in-store}, and @code{enter-store-monad}. The former, is used
to ``run'' a single monadic value through the store:
@example
scheme@@(guile-user)> ,run-in-store (package->derivation hello)
$1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
@end example
The latter enters a recursive REPL, where all the return values are
automatically run through the store:
@example
scheme@@(guile-user)> ,enter-store-monad
store-monad@@(guile-user) [1]> (package->derivation hello)
$2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
$3 = "/gnu/store/@dots{}-foo"
store-monad@@(guile-user) [1]> ,q
scheme@@(guile-user)>
@end example
@noindent
Note that non-monadic values cannot be returned in the
@code{store-monad} REPL.
The main syntactic forms to deal with monads in general are provided by
the @code{(guix monads)} module and are described below.
@deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
in @var{monad}.
@end deffn
@deffn {Scheme Syntax} return @var{val}
Return a monadic value that encapsulates @var{val}.
@end deffn
@deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
@dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
procedures @var{mproc}@dots{}@footnote{This operation is commonly
referred to as ``bind'', but that name denotes an unrelated procedure in
Guile. Thus we use this somewhat cryptic symbol inherited from the
Haskell language.}. There can be one @var{mproc} or several of them, as
in this example:
@example
(run-with-state
(with-monad %state-monad
(>>= (return 1)
(lambda (x) (return (+ 1 x)))
(lambda (x) (return (* 2 x)))))
'some-state)
@result{} 4
@result{} some-state
@end example
@end deffn
@deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
@var{body} ...
@deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
@var{body} ...
Bind the variables @var{var} to the monadic values @var{mval} in
@var{body}. The form (@var{var} -> @var{val}) binds @var{var} to the
``normal'' value @var{val}, as per @code{let}.
@code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
(@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
@end deffn
@deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
Bind @var{mexp} and the following monadic expressions in sequence,
returning the result of the last expression.
This is akin to @code{mlet}, except that the return values of the
monadic expressions are ignored. In that sense, it is analogous to
@code{begin}, but applied to monadic expressions.
@end deffn
@cindex state monad
The @code{(guix monads)} module provides the @dfn{state monad}, which
allows an additional value---the state---to be @emph{threaded} through
monadic procedure calls.
@defvr {Scheme Variable} %state-monad
The state monad. Procedures in the state monad can access and change
the state that is threaded.
Consider the example below. The @code{square} procedure returns a value
in the state monad. It returns the square of its argument, but also
increments the current state value:
@example
(define (square x)
(mlet %state-monad ((count (current-state)))
(mbegin %state-monad
(set-current-state (+ 1 count))
(return (* x x)))))
(run-with-state (sequence %state-monad (map square (iota 3))) 0)
@result{} (0 1 4)
@result{} 3
@end example
When ``run'' through @var{%state-monad}, we obtain that additional state
value, which is the number of @code{square} calls.
@end defvr
@deffn {Monadic Procedure} current-state
Return the current state as a monadic value.
@end deffn
@deffn {Monadic Procedure} set-current-state @var{value}
Set the current state to @var{value} and return the previous state as a
monadic value.
@end deffn
@deffn {Monadic Procedure} state-push @var{value}
Push @var{value} to the current state, which is assumed to be a list,
and return the previous state as a monadic value.
@end deffn
@deffn {Monadic Procedure} state-pop
Pop a value from the current state and return it as a monadic value.
The state is assumed to be a list.
@end deffn
@deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
Run monadic value @var{mval} starting with @var{state} as the initial
state. Return two values: the resulting value, and the resulting state.
@end deffn
The main interface to the store monad, provided by the @code{(guix
store)} module, is as follows.
@defvr {Scheme Variable} %store-monad
The store monad---an alias for @var{%state-monad}.
Values in the store monad encapsulate accesses to the store. When its
effect is needed, a value of the store monad must be ``evaluated'' by
passing it to the @code{run-with-store} procedure (see below.)
@end defvr
@deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
Run @var{mval}, a monadic value in the store monad, in @var{store}, an
open store connection.
@end deffn
@deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
Return as a monadic value the absolute file name in the store of the file
containing @var{text}, a string. @var{references} is a list of store items that the
resulting text file refers to; it defaults to the empty list.
@end deffn
@deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
[#:recursive? #t]
Return the name of @var{file} once interned in the store. Use
@var{name} as its store name, or the basename of @var{file} if
@var{name} is omitted.
When @var{recursive?} is true, the contents of @var{file} are added
recursively; if @var{file} designates a flat file and @var{recursive?}
is true, its contents are added, and its permission bits are kept.
The example below adds a file to the store, under two different names:
@example
(run-with-store (open-connection)
(mlet %store-monad ((a (interned-file "README"))
(b (interned-file "README" "LEGU-MIN")))
(return (list a b))))
@result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
@end example
@end deffn
The @code{(guix packages)} module exports the following package-related
monadic procedures:
@deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
[#:system (%current-system)] [#:target #f] @
[#:output "out"] Return as a monadic
value in the absolute file name of @var{file} within the @var{output}
directory of @var{package}. When @var{file} is omitted, return the name
of the @var{output} directory of @var{package}. When @var{target} is
true, use it as a cross-compilation target triplet.
@end deffn
@deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
@deffnx {Monadic Procedure} package->cross-derivation @var{package} @
@var{target} [@var{system}]
Monadic version of @code{package-derivation} and
@code{package-cross-derivation} (@pxref{Defining Packages}).
@end deffn
@node G-Expressions
@section G-Expressions
@cindex G-expression
@cindex build code quoting
So we have ``derivations'', which represent a sequence of build actions
to be performed to produce an item in the store (@pxref{Derivations}).
Those build actions are performed when asking the daemon to actually
build the derivations; they are run by the daemon in a container
(@pxref{Invoking guix-daemon}).
@cindex strata of code
It should come as no surprise that we like to write those build actions
in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
code@footnote{The term @dfn{stratum} in this context was coined by
Manuel Serrano et al.@: in the context of their work on Hop. Oleg
Kiselyov, who has written insightful
@url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
on this topic}, refers to this kind of code generation as
@dfn{staging}.}: the ``host code''---code that defines packages, talks
to the daemon, etc.---and the ``build code''---code that actually
performs build actions, such as making directories, invoking
@command{make}, etc.
To describe a derivation and its build actions, one typically needs to
embed build code inside host code. It boils down to manipulating build
code as data, and Scheme's homoiconicity---code has a direct
representation as data---comes in handy for that. But we need more than
Scheme's normal @code{quasiquote} mechanism to construct build
expressions.
The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
S-expressions adapted to build expressions. G-expressions, or
@dfn{gexps}, consist essentially in three syntactic forms: @code{gexp},
@code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
@code{#$}, and @code{#$@@}), which are comparable respectively to
@code{quasiquote}, @code{unquote}, and @code{unquote-splicing}
(@pxref{Expression Syntax, @code{quasiquote},, guile, GNU Guile
Reference Manual}). However, there are major differences:
@itemize
@item
Gexps are meant to be written to a file and run or manipulated by other
processes.
@item
When a high-level object such as a package or derivation is unquoted
inside a gexp, the result is as if its output file name had been
introduced.
@item
Gexps carry information about the packages or derivations they refer to,
and these dependencies are automatically added as inputs to the build
processes that use them.
@end itemize
@cindex lowering, of high-level objects in gexps
This mechanism is not limited to package and derivation
objects: @dfn{compilers} able to ``lower'' other high-level objects to
derivations or files in the store can be defined,
such that these objects can also be inserted
into gexps. For example, a useful type of high-level object that can be
inserted in a gexp is ``file-like objects'', which make it easy to
add files to the store and refer to them in
derivations and such (see @code{local-file} and @code{plain-file}
below.)
To illustrate the idea, here is an example of a gexp:
@example
(define build-exp
#~(begin
(mkdir #$output)
(chdir #$output)
(symlink (string-append #$coreutils "/bin/ls")
"list-files")))
@end example
This gexp can be passed to @code{gexp->derivation}; we obtain a
derivation that builds a directory containing exactly one symlink to
@file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
@example
(gexp->derivation "the-thing" build-exp)
@end example
As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
substituted to the reference to the @var{coreutils} package in the
actual build code, and @var{coreutils} is automatically made an input to
the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
output)}) is replaced by a string containing the derivation's output
directory name.
@cindex cross compilation
In a cross-compilation context, it is useful to distinguish between
references to the @emph{native} build of a package---that can run on the
host---versus references to cross builds of a package. To that end, the
@code{#+} plays the same role as @code{#$}, but is a reference to a
native package build:
@example
(gexp->derivation "vi"
#~(begin
(mkdir #$output)
(system* (string-append #+coreutils "/bin/ln")
"-s"
(string-append #$emacs "/bin/emacs")
(string-append #$output "/bin/vi")))
#:target "mips64el-linux")
@end example
@noindent
In the example above, the native build of @var{coreutils} is used, so
that @command{ln} can actually run on the host; but then the
cross-compiled build of @var{emacs} is referenced.
The syntactic form to construct gexps is summarized below.
@deffn {Scheme Syntax} #~@var{exp}
@deffnx {Scheme Syntax} (gexp @var{exp})
Return a G-expression containing @var{exp}. @var{exp} may contain one
or more of the following forms:
@table @code
@item #$@var{obj}
@itemx (ungexp @var{obj})
Introduce a reference to @var{obj}. @var{obj} may have one of the
supported types, for example a package or a
derivation, in which case the @code{ungexp} form is replaced by its
output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
If @var{obj} is a list, it is traversed and references to supported
objects are substituted similarly.
If @var{obj} is another gexp, its contents are inserted and its
dependencies are added to those of the containing gexp.
If @var{obj} is another kind of object, it is inserted as is.
@item #$@var{obj}:@var{output}
@itemx (ungexp @var{obj} @var{output})
This is like the form above, but referring explicitly to the
@var{output} of @var{obj}---this is useful when @var{obj} produces
multiple outputs (@pxref{Packages with Multiple Outputs}).
@item #+@var{obj}
@itemx #+@var{obj}:output
@itemx (ungexp-native @var{obj})
@itemx (ungexp-native @var{obj} @var{output})
Same as @code{ungexp}, but produces a reference to the @emph{native}
build of @var{obj} when used in a cross compilation context.
@item #$output[:@var{output}]
@itemx (ungexp output [@var{output}])
Insert a reference to derivation output @var{output}, or to the main
output when @var{output} is omitted.
This only makes sense for gexps passed to @code{gexp->derivation}.
@item #$@@@var{lst}
@itemx (ungexp-splicing @var{lst})
Like the above, but splices the contents of @var{lst} inside the
containing list.
@item #+@@@var{lst}
@itemx (ungexp-native-splicing @var{lst})
Like the above, but refers to native builds of the objects listed in
@var{lst}.
@end table
G-expressions created by @code{gexp} or @code{#~} are run-time objects
of the @code{gexp?} type (see below.)
@end deffn
@deffn {Scheme Procedure} gexp? @var{obj}
Return @code{#t} if @var{obj} is a G-expression.
@end deffn
G-expressions are meant to be written to disk, either as code building
some derivation, or as plain files in the store. The monadic procedures
below allow you to do that (@pxref{The Store Monad}, for more
information about monads.)
@deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
[#:system (%current-system)] [#:target #f] [#:graft? #t] @
[#:hash #f] [#:hash-algo #f] @
[#:recursive? #f] [#:env-vars '()] [#:modules '()] @
[#:module-path @var{%load-path}] @
[#:references-graphs #f] [#:allowed-references #f] @
[#:leaked-env-vars #f] @
[#:script-name (string-append @var{name} "-builder")] @
[#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
Return a derivation @var{name} that runs @var{exp} (a gexp) with
@var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
stored in a file called @var{script-name}. When @var{target} is true,
it is used as the cross-compilation target triplet for packages referred
to by @var{exp}.
Make @var{modules} available in the evaluation context of @var{exp};
@var{modules} is a list of names of Guile modules searched in
@var{module-path} to be copied in the store, compiled, and made available in
the load path during the execution of @var{exp}---e.g., @code{((guix
build utils) (guix build gnu-build-system))}.
@var{graft?} determines whether packages referred to by @var{exp} should be grafted when
applicable.
When @var{references-graphs} is true, it must be a list of tuples of one of the
following forms:
@example
(@var{file-name} @var{package})
(@var{file-name} @var{package} @var{output})
(@var{file-name} @var{derivation})
(@var{file-name} @var{derivation} @var{output})
(@var{file-name} @var{store-item})
@end example
The right-hand-side of each element of @var{references-graphs} is automatically made
an input of the build process of @var{exp}. In the build environment, each
@var{file-name} contains the reference graph of the corresponding item, in a simple
text format.
@var{allowed-references} must be either @code{#f} or a list of output names and packages.
In the latter case, the list denotes store items that the result is allowed to
refer to. Any reference to another store item will lead to a build error.
The other arguments are as for @code{derivation} (@pxref{Derivations}).
@end deffn
@cindex file-like objects
The @code{local-file}, @code{plain-file}, @code{computed-file},
@code{program-file}, and @code{scheme-file} procedures below return
@dfn{file-like objects}. That is, when unquoted in a G-expression,
these objects lead to a file in the store. Consider this G-expression:
@example
#~(system* (string-append #$glibc "/sbin/nscd") "-f"
#$(local-file "/tmp/my-nscd.conf"))
@end example
The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
to the store. Once expanded, for instance @i{via}
@code{gexp->derivation}, the G-expression refers to that copy under
@file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
does not have any effect on what the G-expression does.
@code{plain-file} can be used similarly; it differs in that the file
content is directly passed as a string.
@deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
[#:recursive? #t]
Return an object representing local file @var{file} to add to the store; this
object can be used in a gexp. If @var{file} is a relative file name, it is looked
up relative to the source file where this form appears. @var{file} will be added to
the store under @var{name}--by default the base name of @var{file}.
When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
designates a flat file and @var{recursive?} is true, its contents are added, and its
permission bits are kept.
This is the declarative counterpart of the @code{interned-file} monadic
procedure (@pxref{The Store Monad, @code{interned-file}}).
@end deffn
@deffn {Scheme Procedure} plain-file @var{name} @var{content}
Return an object representing a text file called @var{name} with the given
@var{content} (a string) to be added to the store.
This is the declarative counterpart of @code{text-file}.
@end deffn
@deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
[#:modules '()] [#:options '(#:local-build? #t)]
Return an object representing the store item @var{name}, a file or
directory computed by @var{gexp}. @var{modules} specifies the set of
modules visible in the execution context of @var{gexp}. @var{options}
is a list of additional arguments to pass to @code{gexp->derivation}.
This is the declarative counterpart of @code{gexp->derivation}.
@end deffn
@deffn {Monadic Procedure} gexp->script @var{name} @var{exp}
Return an executable script @var{name} that runs @var{exp} using
@var{guile} with @var{modules} in its search path.
The example below builds a script that simply invokes the @command{ls}
command:
@example
(use-modules (guix gexp) (gnu packages base))
(gexp->script "list-files"
#~(execl (string-append #$coreutils "/bin/ls")
"ls"))
@end example
When ``running'' it through the store (@pxref{The Store Monad,
@code{run-with-store}}), we obtain a derivation that produces an
executable file @file{/gnu/store/@dots{}-list-files} along these lines:
@example
#!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
!#
(execl (string-append "/gnu/store/@dots{}-coreutils-8.22"/bin/ls")
"ls")
@end example
@end deffn
@deffn {Scheme Procedure} program-file @var{name} @var{exp} @
[#:modules '()] [#:guile #f]
Return an object representing the executable store item @var{name} that
runs @var{gexp}. @var{guile} is the Guile package used to execute that
script, and @var{modules} is the list of modules visible to that script.
This is the declarative counterpart of @code{gexp->script}.
@end deffn
@deffn {Monadic Procedure} gexp->file @var{name} @var{exp}
Return a derivation that builds a file @var{name} containing @var{exp}.
The resulting file holds references to all the dependencies of @var{exp}
or a subset thereof.
@end deffn
@deffn {Scheme Procedure} scheme-file @var{name} @var{exp}
Return an object representing the Scheme file @var{name} that contains
@var{exp}.
This is the declarative counterpart of @code{gexp->file}.
@end deffn
@deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
Return as a monadic value a derivation that builds a text file
containing all of @var{text}. @var{text} may list, in addition to
strings, objects of any type that can be used in a gexp: packages,
derivations, local file objects, etc. The resulting store file holds
references to all these.
This variant should be preferred over @code{text-file} anytime the file
to create will reference items from the store. This is typically the
case when building a configuration file that embeds store file names,
like this:
@example
(define (profile.sh)
;; Return the name of a shell script in the store that
;; initializes the 'PATH' environment variable.
(text-file* "profile.sh"
"export PATH=" coreutils "/bin:"
grep "/bin:" sed "/bin\n"))
@end example
In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
will references @var{coreutils}, @var{grep}, and @var{sed}, thereby
preventing them from being garbage-collected during its lifetime.
@end deffn
@deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
Return an object representing store file @var{name} containing
@var{text}. @var{text} is a sequence of strings and file-like objects,
as in:
@example
(mixed-text-file "profile"
"export PATH=" coreutils "/bin:" grep "/bin")
@end example
This is the declarative counterpart of @code{text-file*}.
@end deffn
Of course, in addition to gexps embedded in ``host'' code, there are
also modules containing build tools. To make it clear that they are
meant to be used in the build stratum, these modules are kept in the
@code{(guix build @dots{})} name space.
@cindex lowering, of high-level objects in gexps
Internally, high-level objects are @dfn{lowered}, using their compiler,
to either derivations or store items. For instance, lowering a package
yields a derivation, and lowering a @code{plain-file} yields a store
item. This is achieved using the @code{lower-object} monadic procedure.
@deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
[#:target #f]
Return as a value in @var{%store-monad} the derivation or store item
corresponding to @var{obj} for @var{system}, cross-compiling for
@var{target} if @var{target} is true. @var{obj} must be an object that
has an associated gexp compiler, such as a @code{<package>}.
@end deffn
@c *********************************************************************
@node Utilities
@chapter Utilities
This section describes tools primarily targeted at developers and users
who write new package definitions. They complement the Scheme
programming interface of Guix in a convenient way.
@menu
* Invoking guix build:: Building packages from the command line.
* Invoking guix edit:: Editing package definitions.
* Invoking guix download:: Downloading a file and printing its hash.
* Invoking guix hash:: Computing the cryptographic hash of a file.
* Invoking guix import:: Importing package definitions.
* Invoking guix refresh:: Updating package definitions.
* Invoking guix lint:: Finding errors in package definitions.
* Invoking guix size:: Profiling disk usage.
* Invoking guix graph:: Visualizing the graph of packages.
* Invoking guix environment:: Setting up development environments.
* Invoking guix publish:: Sharing substitutes.
* Invoking guix challenge:: Challenging substitute servers.
* Invoking guix container:: Process isolation.
@end menu
@node Invoking guix build
@section Invoking @command{guix build}
The @command{guix build} command builds packages or derivations and
their dependencies, and prints the resulting store paths. Note that it
does not modify the user's profile---this is the job of the
@command{guix package} command (@pxref{Invoking guix package}). Thus,
it is mainly useful for distribution developers.
The general syntax is:
@example
guix build @var{options} @var{package-or-derivation}@dots{}
@end example
@var{package-or-derivation} may be either the name of a package found in
the software distribution such as @code{coreutils} or
@code{coreutils-8.20}, or a derivation such as
@file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
package with the corresponding name (and optionally version) is searched
for among the GNU distribution modules (@pxref{Package Modules}).
Alternatively, the @code{--expression} option may be used to specify a
Scheme expression that evaluates to a package; this is useful when
disambiguation among several same-named packages or package variants is
needed.
The @var{options} may be zero or more of the following:
@table @code
@item --file=@var{file}
@itemx -f @var{file}
Build the package or derivation that the code within @var{file}
evaluates to.
As an example, @var{file} might contain a package definition like this
(@pxref{Defining Packages}):
@example
@verbatiminclude package-hello.scm
@end example
@item --expression=@var{expr}
@itemx -e @var{expr}
Build the package or derivation @var{expr} evaluates to.
For example, @var{expr} may be @code{(@@ (gnu packages guile)
guile-1.8)}, which unambiguously designates this specific variant of
version 1.8 of Guile.
Alternately, @var{expr} may be a G-expression, in which case it is used
as a build program passed to @code{gexp->derivation}
(@pxref{G-Expressions}).
Lastly, @var{expr} may refer to a zero-argument monadic procedure
(@pxref{The Store Monad}). The procedure must return a derivation as a
monadic value, which is then passed through @code{run-with-store}.
@item --source
@itemx -S
Build the packages' source derivations, rather than the packages
themselves.
For instance, @code{guix build -S gcc} returns something like
@file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is GCC's source tarball.
The returned source tarball is the result of applying any patches and
code snippets specified in the package's @code{origin} (@pxref{Defining
Packages}).
@item --sources
Fetch and return the source of @var{package-or-derivation} and all their
dependencies, recursively. This is a handy way to obtain a local copy
of all the source code needed to build @var{packages}, allowing you to
eventually build them even without network access. It is an extension
of the @code{--source} option and can accept one of the following
optional argument values:
@table @code
@item package
This value causes the @code{--sources} option to behave in the same way
as the @code{--source} option.
@item all
Build all packages' source derivations, including any source that might
be listed as @code{inputs}. This is the default value.
@example
$ guix build --sources tzdata
The following derivations will be built:
/gnu/store/@dots{}-tzdata2015b.tar.gz.drv
/gnu/store/@dots{}-tzcode2015b.tar.gz.drv
@end example
@item transitive
Build all packages' source derivations, as well as all source
derivations for packages' transitive inputs. This can be used e.g. to
prefetch package source for later offline building.
@example
$ guix build --sources=transitive tzdata
The following derivations will be built:
/gnu/store/@dots{}-tzcode2015b.tar.gz.drv
/gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
/gnu/store/@dots{}-grep-2.21.tar.xz.drv
/gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
/gnu/store/@dots{}-make-4.1.tar.xz.drv
/gnu/store/@dots{}-bash-4.3.tar.xz.drv
@dots{}
@end example
@end table
@item --system=@var{system}
@itemx -s @var{system}
Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
the host's system type.
An example use of this is on Linux-based systems, which can emulate
different personalities. For instance, passing
@code{--system=i686-linux} on an @code{x86_64-linux} system allows users
to build packages in a complete 32-bit environment.
@item --target=@var{triplet}
@cindex cross-compilation
Cross-build for @var{triplet}, which must be a valid GNU triplet, such
as @code{"mips64el-linux-gnu"} (@pxref{Configuration Names, GNU
configuration triplets,, configure, GNU Configure and Build System}).
@item --with-source=@var{source}
Use @var{source} as the source of the corresponding package.
@var{source} must be a file name or a URL, as for @command{guix
download} (@pxref{Invoking guix download}).
The ``corresponding package'' is taken to be one specified on the
command line whose name matches the base of @var{source}---e.g., if
@var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
package is @code{guile}. Likewise, the version string is inferred from
@var{source}; in the previous example, it's @code{2.0.10}.
This option allows users to try out versions of packages other than the
one provided by the distribution. The example below downloads
@file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
the @code{ed} package:
@example
guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
@end example
As a developer, @code{--with-source} makes it easy to test release
candidates:
@example
guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
@end example
@dots{} or to build from a checkout in a pristine environment:
@example
$ git clone git://git.sv.gnu.org/guix.git
$ guix build guix --with-source=./guix
@end example
@anchor{build-check}
@item --check
@cindex determinism, checking
@cindex reproducibility, checking
Rebuild @var{package-or-derivation}, which are already available in the
store, and raise an error if the build results are not bit-for-bit
identical.
This mechanism allows you to check whether previously-installed
substitutes are genuine (@pxref{Substitutes}), or whether a package's
build result is deterministic. @xref{Invoking guix challenge}, for more
background information and tools.
@item --no-grafts
Do not ``graft'' packages. In practice, this means that package updates
available as grafts are not applied. @xref{Security Updates}, for more
information on grafts.
@item --derivations
@itemx -d
Return the derivation paths, not the output paths, of the given
packages.
@item --root=@var{file}
@itemx -r @var{file}
Make @var{file} a symlink to the result, and register it as a garbage
collector root.
@item --log-file
Return the build log file names or URLs for the given
@var{package-or-derivation}s, or raise an error if build logs are
missing.
This works regardless of how packages or derivations are specified. For
instance, the following invocations are equivalent:
@example
guix build --log-file `guix build -d guile`
guix build --log-file `guix build guile`
guix build --log-file guile
guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
@end example
If a log is unavailable locally, and unless @code{--no-substitutes} is
passed, the command looks for a corresponding log on one of the
substitute servers (as specified with @code{--substitute-urls}.)
So for instance, let's say you want to see the build log of GDB on MIPS
but you're actually on an @code{x86_64} machine:
@example
$ guix build --log-file gdb -s mips64el-linux
http://hydra.gnu.org/log/@dots{}-gdb-7.10
@end example
You can freely access a huge library of build logs!
@end table
@cindex common build options
In addition, a number of options that control the build process are
common to @command{guix build} and other commands that can spawn builds,
such as @command{guix package} or @command{guix archive}. These are the
following:
@table @code
@item --load-path=@var{directory}
@itemx -L @var{directory}
Add @var{directory} to the front of the package module search path
(@pxref{Package Modules}).
This allows users to define their own packages and make them visible to
the command-line tools.
@item --keep-failed
@itemx -K
Keep the build tree of failed builds. Thus, if a build fail, its build
tree is kept under @file{/tmp}, in a directory whose name is shown at
the end of the build log. This is useful when debugging build issues.
@item --keep-going
@itemx -k
Keep going when some of the derivations fail to build; return only once
all the builds have either completed or failed.
The default behavior is to stop as soon as one of the specified
derivations has failed.
@item --dry-run
@itemx -n
Do not build the derivations.
@item --fallback
When substituting a pre-built binary fails, fall back to building
packages locally.
@item --substitute-urls=@var{urls}
@anchor{client-substitute-urls}
Consider @var{urls} the whitespace-separated list of substitute source
URLs, overriding the default list of URLs of @command{guix-daemon}
(@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
This means that substitutes may be downloaded from @var{urls}, provided
they are signed by a key authorized by the system administrator
(@pxref{Substitutes}).
@item --no-substitutes
Do not use substitutes for build products. That is, always build things
locally instead of allowing downloads of pre-built binaries
(@pxref{Substitutes}).
@item --rounds=@var{n}
Build each derivation @var{n} times in a row, and raise an error if
consecutive build results are not bit-for-bit identical.
This is a useful way to detect non-deterministic builds processes.
Non-deterministic build processes are a problem because they make it
practically impossible for users to @emph{verify} whether third-party
binaries are genuine. @xref{Invoking guix challenge}, for more.
Note that, currently, the differing build results are not kept around,
so you will have to manually investigate in case of an error---e.g., by
stashing one of the build results with @code{guix archive --export},
then rebuilding, and finally comparing the two results.
@item --no-build-hook
Do not attempt to offload builds @i{via} the daemon's ``build hook''
(@pxref{Daemon Offload Setup}). That is, always build things locally
instead of offloading builds to remote machines.
@item --max-silent-time=@var{seconds}
When the build or substitution process remains silent for more than
@var{seconds}, terminate it and report a build failure.
@item --timeout=@var{seconds}
Likewise, when the build or substitution process lasts for more than
@var{seconds}, terminate it and report a build failure.
By default there is no timeout. This behavior can be restored with
@code{--timeout=0}.
@item --verbosity=@var{level}
Use the given verbosity level. @var{level} must be an integer between 0
and 5; higher means more verbose output. Setting a level of 4 or more
may be helpful when debugging setup issues with the build daemon.
@item --cores=@var{n}
@itemx -c @var{n}
Allow the use of up to @var{n} CPU cores for the build. The special
value @code{0} means to use as many CPU cores as available.
@item --max-jobs=@var{n}
@itemx -M @var{n}
Allow at most @var{n} build jobs in parallel. @xref{Invoking
guix-daemon, @code{--max-jobs}}, for details about this option and the
equivalent @command{guix-daemon} option.
@end table
Behind the scenes, @command{guix build} is essentially an interface to
the @code{package-derivation} procedure of the @code{(guix packages)}
module, and to the @code{build-derivations} procedure of the @code{(guix
derivations)} module.
In addition to options explicitly passed on the command line,
@command{guix build} and other @command{guix} commands that support
building honor the @code{GUIX_BUILD_OPTIONS} environment variable.
@defvr {Environment Variable} GUIX_BUILD_OPTIONS
Users can define this variable to a list of command line options that
will automatically be used by @command{guix build} and other
@command{guix} commands that can perform builds, as in the example
below:
@example
$ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
@end example
These options are parsed independently, and the result is appended to
the parsed command-line options.
@end defvr
@node Invoking guix edit
@section Invoking @command{guix edit}
@cindex package definition, editing
So many packages, so many source files! The @command{guix edit} command
facilitates the life of packagers by pointing their editor at the source
file containing the definition of the specified packages. For instance:
@example
guix edit gcc-4.8 vim
@end example
@noindent
launches the program specified in the @code{VISUAL} or in the
@code{EDITOR} environment variable to edit the recipe of GCC@tie{}4.8.4
and that of Vim.
If you are using Emacs, note that the Emacs user interface provides
similar functionality in the ``package info'' and ``package list''
buffers created by @kbd{M-x guix-search-by-name} and similar commands
(@pxref{Emacs Commands}).
@node Invoking guix download
@section Invoking @command{guix download}
When writing a package definition, developers typically need to download
the package's source tarball, compute its SHA256 hash, and write that
hash in the package definition (@pxref{Defining Packages}). The
@command{guix download} tool helps with this task: it downloads a file
from the given URI, adds it to the store, and prints both its file name
in the store and its SHA256 hash.
The fact that the downloaded file is added to the store saves bandwidth:
when the developer eventually tries to build the newly defined package
with @command{guix build}, the source tarball will not have to be
downloaded again because it is already in the store. It is also a
convenient way to temporarily stash files, which may be deleted
eventually (@pxref{Invoking guix gc}).
The @command{guix download} command supports the same URIs as used in
package definitions. In particular, it supports @code{mirror://} URIs.
@code{https} URIs (HTTP over TLS) are supported @emph{provided} the
Guile bindings for GnuTLS are available in the user's environment; when
they are not available, an error is raised. @xref{Guile Preparations,
how to install the GnuTLS bindings for Guile,, gnutls-guile,
GnuTLS-Guile}, for more information.
The following option is available:
@table @code
@item --format=@var{fmt}
@itemx -f @var{fmt}
Write the hash in the format specified by @var{fmt}. For more
information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
@end table
@node Invoking guix hash
@section Invoking @command{guix hash}
The @command{guix hash} command computes the SHA256 hash of a file.
It is primarily a convenience tool for anyone contributing to the
distribution: it computes the cryptographic hash of a file, which can be
used in the definition of a package (@pxref{Defining Packages}).
The general syntax is:
@example
guix hash @var{option} @var{file}
@end example
@command{guix hash} has the following option:
@table @code
@item --format=@var{fmt}
@itemx -f @var{fmt}
Write the hash in the format specified by @var{fmt}.
Supported formats: @code{nix-base32}, @code{base32}, @code{base16}
(@code{hex} and @code{hexadecimal} can be used as well).
If the @option{--format} option is not specified, @command{guix hash}
will output the hash in @code{nix-base32}. This representation is used
in the definitions of packages.
@item --recursive
@itemx -r
Compute the hash on @var{file} recursively.
In this case, the hash is computed on an archive containing @var{file},
including its children if it is a directory. Some of @var{file}'s
meta-data is part of the archive; for instance, when @var{file} is a
regular file, the hash is different depending on whether @var{file} is
executable or not. Meta-data such as time stamps has no impact on the
hash (@pxref{Invoking guix archive}).
@c FIXME: Replace xref above with xref to an ``Archive'' section when
@c it exists.
@end table
@node Invoking guix import
@section Invoking @command{guix import}
@cindex importing packages
@cindex package import
@cindex package conversion
The @command{guix import} command is useful for people willing to add a
package to the distribution but who'd rather do as little work as
possible to get there---a legitimate demand. The command knows of a few
repositories from which it can ``import'' package meta-data. The result
is a package definition, or a template thereof, in the format we know
(@pxref{Defining Packages}).
The general syntax is:
@example
guix import @var{importer} @var{options}@dots{}
@end example
@var{importer} specifies the source from which to import package
meta-data, and @var{options} specifies a package identifier and other
options specific to @var{importer}. Currently, the available
``importers'' are:
@table @code
@item gnu
Import meta-data for the given GNU package. This provides a template
for the latest version of that GNU package, including the hash of its
source tarball, and its canonical synopsis and description.
Additional information such as the package's dependencies and its
license needs to be figured out manually.
For example, the following command returns a package definition for
GNU@tie{}Hello:
@example
guix import gnu hello
@end example
Specific command-line options are:
@table @code
@item --key-download=@var{policy}
As for @code{guix refresh}, specify the policy to handle missing OpenPGP
keys when verifying the package's signature. @xref{Invoking guix
refresh, @code{--key-download}}.
@end table
@item pypi
@cindex pypi
Import meta-data from the @uref{https://pypi.python.org/, Python Package
Index}@footnote{This functionality requires Guile-JSON to be installed.
@xref{Requirements}.}. Information is taken from the JSON-formatted
description available at @code{pypi.python.org} and usually includes all
the relevant information, including package dependencies.
The command below imports meta-data for the @code{itsdangerous} Python
package:
@example
guix import pypi itsdangerous
@end example
@item gem
@cindex gem
Import meta-data from @uref{https://rubygems.org/,
RubyGems}@footnote{This functionality requires Guile-JSON to be
installed. @xref{Requirements}.}. Information is taken from the
JSON-formatted description available at @code{rubygems.org} and includes
most relevant information, including runtime dependencies. There are
some caveats, however. The meta-data doesn't distinguish between
synopses and descriptions, so the same string is used for both fields.
Additionally, the details of non-Ruby dependencies required to build
native extensions is unavailable and left as an exercise to the
packager.
The command below imports meta-data for the @code{rails} Ruby package:
@example
guix import gem rails
@end example
@item cpan
@cindex CPAN
Import meta-data from @uref{https://www.metacpan.org/, MetaCPAN}.
Information is taken from the JSON-formatted meta-data provided through
@uref{https://api.metacpan.org/, MetaCPAN's API} and includes most
relevant information, such as module dependencies. License information
should be checked closely. If Perl is available in the store, then the
@code{corelist} utility will be used to filter core modules out of the
list of dependencies.
The command command below imports meta-data for the @code{Acme::Boolean}
Perl module:
@example
guix import cpan Acme::Boolean
@end example
@item cran
@cindex CRAN
@cindex Bioconductor
Import meta-data from @uref{http://cran.r-project.org/, CRAN}, the
central repository for the @uref{http://r-project.org, GNU@tie{}R
statistical and graphical environment}.
Information is extracted from the package's @code{DESCRIPTION} file.
The command command below imports meta-data for the @code{Cairo}
R package:
@example
guix import cran Cairo
@end example
When @code{--archive=bioconductor} is added, meta-data is imported from
@uref{http://www.bioconductor.org/, Bioconductor}, a repository of R
packages for for the analysis and comprehension of high-throughput
genomic data in bioinformatics.
Information is extracted from a package's @code{DESCRIPTION} file
published on the web interface of the Bioconductor SVN repository.
The command command below imports meta-data for the @code{GenomicRanges}
R package:
@example
guix import cran --archive=bioconductor GenomicRanges
@end example
@item nix
Import meta-data from a local copy of the source of the
@uref{http://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
relies on the @command{nix-instantiate} command of
@uref{http://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
typically written in a mixture of Nix-language and Bash code. This
command only imports the high-level package structure that is written in
the Nix language. It normally includes all the basic fields of a
package definition.
When importing a GNU package, the synopsis and descriptions are replaced
by their canonical upstream variant.
Usually, you will first need to do:
@example
export NIX_REMOTE=daemon
@end example
@noindent
so that @command{nix-instantiate} does not try to open the Nix database.
As an example, the command below imports the package definition of
LibreOffice (more precisely, it imports the definition of the package
bound to the @code{libreoffice} top-level attribute):
@example
guix import nix ~/path/to/nixpkgs libreoffice
@end example
@item hackage
@cindex hackage
Import meta-data from Haskell community's central package archive
@uref{https://hackage.haskell.org/, Hackage}. Information is taken from
Cabal files and includes all the relevant information, including package
dependencies.
Specific command-line options are:
@table @code
@item --stdin
@itemx -s
Read a Cabal file from the standard input.
@item --no-test-dependencies
@itemx -t
Do not include dependencies required by the test suites only.
@item --cabal-environment=@var{alist}
@itemx -e @var{alist}
@var{alist} is a Scheme alist defining the environment in which the
Cabal conditionals are evaluated. The accepted keys are: @code{os},
@code{arch}, @code{impl} and a string representing the name of a flag.
The value associated with a flag has to be either the symbol
@code{true} or @code{false}. The value associated with other keys
has to conform to the Cabal file format definition. The default value
associated with the keys @code{os}, @code{arch} and @code{impl} is
@samp{linux}, @samp{x86_64} and @samp{ghc} respectively.
@end table
The command below imports meta-data for the latest version of the
@code{HTTP} Haskell package without including test dependencies and
specifying the value of the flag @samp{network-uri} as @code{false}:
@example
guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
@end example
A specific package version may optionally be specified by following the
package name by a hyphen and a version number as in the following example:
@example
guix import hackage mtl-2.1.3.1
@end example
@item elpa
@cindex elpa
Import meta-data from an Emacs Lisp Package Archive (ELPA) package
repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
Specific command-line options are:
@table @code
@item --archive=@var{repo}
@itemx -a @var{repo}
@var{repo} identifies the archive repository from which to retrieve the
information. Currently the supported repositories and their identifiers
are:
@itemize -
@item
@uref{http://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
identifier. This is the default.
@item
@uref{http://stable.melpa.org/packages, MELPA-Stable}, selected by the
@code{melpa-stable} identifier.
@item
@uref{http://melpa.org/packages, MELPA}, selected by the @code{melpa}
identifier.
@end itemize
@end table
@end table
The structure of the @command{guix import} code is modular. It would be
useful to have more importers for other package formats, and your help
is welcome here (@pxref{Contributing}).
@node Invoking guix refresh
@section Invoking @command{guix refresh}
The primary audience of the @command{guix refresh} command is developers
of the GNU software distribution. By default, it reports any packages
provided by the distribution that are outdated compared to the latest
upstream version, like this:
@example
$ guix refresh
gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
@end example
It does so by browsing each package's FTP directory and determining the
highest version number of the source tarballs therein. The command
knows how to update specific types of packages: GNU packages, ELPA
packages, etc.---see the documentation for @option{--type} below. The
are many packages, though, for which it lacks a method to determine
whether a new upstream release is available. However, the mechanism is
extensible, so feel free to get in touch with us to add a new method!
When passed @code{--update}, it modifies distribution source files to
update the version numbers and source tarball hashes of those packages'
recipes (@pxref{Defining Packages}). This is achieved by downloading
each package's latest source tarball and its associated OpenPGP
signature, authenticating the downloaded tarball against its signature
using @command{gpg}, and finally computing its hash. When the public
key used to sign the tarball is missing from the user's keyring, an
attempt is made to automatically retrieve it from a public key server;
when it's successful, the key is added to the user's keyring; otherwise,
@command{guix refresh} reports an error.
The following options are supported:
@table @code
@item --expression=@var{expr}
@itemx -e @var{expr}
Consider the package @var{expr} evaluates to.
This is useful to precisely refer to a package, as in this example:
@example
guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
@end example
This command lists the dependents of the ``final'' libc (essentially all
the packages.)
@item --update
@itemx -u
Update distribution source files (package recipes) in place. This is
usually run from a checkout of the Guix source tree (@pxref{Running
Guix Before It Is Installed}):
@example
$ ./pre-inst-env guix refresh -s non-core
@end example
@xref{Defining Packages}, for more information on package definitions.
@item --select=[@var{subset}]
@itemx -s @var{subset}
Select all the packages in @var{subset}, one of @code{core} or
@code{non-core}.
The @code{core} subset refers to all the packages at the core of the
distribution---i.e., packages that are used to build ``everything
else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
changing one of these packages in the distribution entails a rebuild of
all the others. Thus, such updates are an inconvenience to users in
terms of build time or bandwidth used to achieve the upgrade.
The @code{non-core} subset refers to the remaining packages. It is
typically useful in cases where an update of the core packages would be
inconvenient.
@item --type=@var{updater}
@itemx -t @var{updater}
Select only packages handled by @var{updater} (may be a comma-separated
list of updaters). Currently, @var{updater} may be one of:
@table @code
@item gnu
the updater for GNU packages;
@item gnome
the updater for GNOME packages;
@item elpa
the updater for @uref{http://elpa.gnu.org/, ELPA} packages;
@item cran
the updater for @uref{http://cran.r-project.org/, CRAN} packages;
@item bioconductor
the updater for @uref{http://www.bioconductor.org/, Bioconductor} R packages;
@item pypi
the updater for @uref{https://pypi.python.org, PyPI} packages.
@end table
For instance, the following commands only checks for updates of Emacs
packages hosted at @code{elpa.gnu.org} and updates of CRAN packages:
@example
$ guix refresh --type=elpa,cran
gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
@end example
@end table
In addition, @command{guix refresh} can be passed one or more package
names, as in this example:
@example
$ ./pre-inst-env guix refresh -u emacs idutils gcc-4.8.4
@end example
@noindent
The command above specifically updates the @code{emacs} and
@code{idutils} packages. The @code{--select} option would have no
effect in this case.
When considering whether to upgrade a package, it is sometimes
convenient to know which packages would be affected by the upgrade and
should be checked for compatibility. For this the following option may
be used when passing @command{guix refresh} one or more package names:
@table @code
@item --list-updaters
@itemx -L
List available updaters and exit (see @option{--type} above.)
@item --list-dependent
@itemx -l
List top-level dependent packages that would need to be rebuilt as a
result of upgrading one or more packages.
@end table
Be aware that the @code{--list-dependent} option only
@emph{approximates} the rebuilds that would be required as a result of
an upgrade. More rebuilds might be required under some circumstances.
@example
$ guix refresh --list-dependent flex
Building the following 120 packages would ensure 213 dependent packages are rebuilt:
hop-2.4.0 geiser-0.4 notmuch-0.18 mu-0.9.9.5 cflow-1.4 idutils-4.6 @dots{}
@end example
The command above lists a set of packages that could be built to check
for compatibility with an upgraded @code{flex} package.
The following options can be used to customize GnuPG operation:
@table @code
@item --gpg=@var{command}
Use @var{command} as the GnuPG 2.x command. @var{command} is searched
for in @code{$PATH}.
@item --key-download=@var{policy}
Handle missing OpenPGP keys according to @var{policy}, which may be one
of:
@table @code
@item always
Always download missing OpenPGP keys from the key server, and add them
to the user's GnuPG keyring.
@item never
Never try to download missing OpenPGP keys. Instead just bail out.
@item interactive
When a package signed with an unknown OpenPGP key is encountered, ask
the user whether to download it or not. This is the default behavior.
@end table
@item --key-server=@var{host}
Use @var{host} as the OpenPGP key server when importing a public key.
@end table
@node Invoking guix lint
@section Invoking @command{guix lint}
The @command{guix lint} is meant to help package developers avoid common
errors and use a consistent style. It runs a number of checks on a
given set of packages in order to find common mistakes in their
definitions. Available @dfn{checkers} include (see
@code{--list-checkers} for a complete list):
@table @code
@item synopsis
@itemx description
Validate certain typographical and stylistic rules about package
descriptions and synopses.
@item inputs-should-be-native
Identify inputs that should most likely be native inputs.
@item source
@itemx home-page
@itemx source-file-name
Probe @code{home-page} and @code{source} URLs and report those that are
invalid. Check that the source file name is meaningful, e.g. is not
just a version number or ``git-checkout'', and should not have a
@code{file-name} declared (@pxref{origin Reference}).
@item cve
Report known vulnerabilities found in the Common Vulnerabilities and
Exposures (CVE) database
@uref{https://nvd.nist.gov/download.cfm#CVE_FEED, published by the US
NIST}.
@item formatting
Warn about obvious source code formatting issues: trailing white space,
use of tabulations, etc.
@end table
The general syntax is:
@example
guix lint @var{options} @var{package}@dots{}
@end example
If no package is given on the command line, then all packages are checked.
The @var{options} may be zero or more of the following:
@table @code
@item --checkers
@itemx -c
Only enable the checkers specified in a comma-separated list using the
names returned by @code{--list-checkers}.
@item --list-checkers
@itemx -l
List and describe all the available checkers that will be run on packages
and exit.
@end table
@node Invoking guix size
@section Invoking @command{guix size}
The @command{guix size} command helps package developers profile the
disk usage of packages. It is easy to overlook the impact of an
additional dependency added to a package, or the impact of using a
single output for a package that could easily be split (@pxref{Packages
with Multiple Outputs}). These are the typical issues that
@command{guix size} can highlight.
The command can be passed a package specification such as @code{gcc-4.8}
or @code{guile:debug}, or a file name in the store. Consider this
example:
@example
$ guix size coreutils
store item total self
/gnu/store/@dots{}-coreutils-8.23 70.0 13.9 19.8%
/gnu/store/@dots{}-gmp-6.0.0a 55.3 2.5 3.6%
/gnu/store/@dots{}-acl-2.2.52 53.7 0.5 0.7%
/gnu/store/@dots{}-attr-2.4.46 53.2 0.3 0.5%
/gnu/store/@dots{}-gcc-4.8.4-lib 52.9 15.7 22.4%
/gnu/store/@dots{}-glibc-2.21 37.2 37.2 53.1%
@end example
@cindex closure
The store items listed here constitute the @dfn{transitive closure} of
Coreutils---i.e., Coreutils and all its dependencies, recursively---as
would be returned by:
@example
$ guix gc -R /gnu/store/@dots{}-coreutils-8.23
@end example
Here the output shows 3 columns next to store items. The first column,
labeled ``total'', shows the size in mebibytes (MiB) of the closure of
the store item---that is, its own size plus the size of all its
dependencies. The next column, labeled ``self'', shows the size of the
item itself. The last column shows the ratio of the item's size to the
space occupied by all the items listed here.
In this example, we see that the closure of Coreutils weighs in at
70@tie{}MiB, half of which is taken by libc. (That libc represents a
large fraction of the closure is not a problem @i{per se} because it is
always available on the system anyway.)
When the package passed to @command{guix size} is available in the
store, @command{guix size} queries the daemon to determine its
dependencies, and measures its size in the store, similar to @command{du
-ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
Coreutils}).
When the given package is @emph{not} in the store, @command{guix size}
reports information based on information about the available substitutes
(@pxref{Substitutes}). This allows it to profile disk usage of store
items that are not even on disk, only available remotely.
The available options are:
@table @option
@item --substitute-urls=@var{urls}
Use substitute information from @var{urls}.
@xref{client-substitute-urls, the same option for @code{guix build}}.
@item --map-file=@var{file}
Write to @var{file} a graphical map of disk usage as a PNG file.
For the example above, the map looks like this:
@image{images/coreutils-size-map,5in,, map of Coreutils disk usage
produced by @command{guix size}}
This option requires that
@uref{http://wingolog.org/software/guile-charting/, Guile-Charting} be
installed and visible in Guile's module search path. When that is not
the case, @command{guix size} fails as it tries to load it.
@item --system=@var{system}
@itemx -s @var{system}
Consider packages for @var{system}---e.g., @code{x86_64-linux}.
@end table
@node Invoking guix graph
@section Invoking @command{guix graph}
@cindex DAG
Packages and their dependencies form a @dfn{graph}, specifically a
directed acyclic graph (DAG). It can quickly become difficult to have a
mental model of the package DAG, so the @command{guix graph} command is
here to provide a visual representation of the DAG. @command{guix
graph} emits a DAG representation in the input format of
@uref{http://www.graphviz.org/, Graphviz}, so its output can be passed
directly to Graphviz's @command{dot} command, for instance. The general
syntax is:
@example
guix graph @var{options} @var{package}@dots{}
@end example
For example, the following command generates a PDF file representing the
package DAG for the GNU@tie{}Core Utilities, showing its build-time
dependencies:
@example
guix graph coreutils | dot -Tpdf > dag.pdf
@end example
The output looks like this:
@image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
Nice little graph, no?
But there's more than one graph! The one above is concise: it's the
graph of package objects, omitting implicit inputs such as GCC, libc,
grep, etc. It's often useful to have such a concise graph, but
sometimes you want to see more details. @command{guix graph} supports
several types of graphs, allowing you to choose the level of details:
@table @code
@item package
This is the default type, the one we used above. It shows the DAG of
package objects, excluding implicit dependencies. It is concise, but
filters out many details.
@item bag-emerged
This is the package DAG, @emph{including} implicit inputs.
For instance, the following command:
@example
guix graph --type=bag-emerged coreutils | dot -Tpdf > dag.pdf
@end example
... yields this bigger graph:
@image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
At the bottom of the graph, we see all the implicit inputs of
@var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
Now, note that the dependencies of those implicit inputs---that is, the
@dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
here, for conciseness.
@item bag
Similar to @code{bag-emerged}, but this time including all the bootstrap
dependencies.
@item bag-with-origins
Similar to @code{bag}, but also showing origins and their dependencies.
@item derivations
This is the most detailed representation: It shows the DAG of
derivations (@pxref{Derivations}) and plain store items. Compared to
the above representation, many additional nodes are visible, including
builds scripts, patches, Guile modules, etc.
@end table
All the above types correspond to @emph{build-time dependencies}. The
following graph type represents the @emph{run-time dependencies}:
@table @code
@item references
This is the graph of @dfn{references} of a package output, as returned
by @command{guix gc --references} (@pxref{Invoking guix gc}).
If the given package output is not available in the store, @command{guix
graph} attempts to obtain dependency information from substitutes.
@end table
The available options are the following:
@table @option
@item --type=@var{type}
@itemx -t @var{type}
Produce a graph output of @var{type}, where @var{type} must be one of
the values listed above.
@item --list-types
List the supported graph types.
@item --expression=@var{expr}
@itemx -e @var{expr}
Consider the package @var{expr} evaluates to.
This is useful to precisely refer to a package, as in this example:
@example
guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
@end example
@end table
@node Invoking guix environment
@section Invoking @command{guix environment}
@cindex reproducible build environments
@cindex development environments
The purpose of @command{guix environment} is to assist hackers in
creating reproducible development environments without polluting their
package profile. The @command{guix environment} tool takes one or more
packages, builds all of the necessary inputs, and creates a shell
environment to use them.
The general syntax is:
@example
guix environment @var{options} @var{package}@dots{}
@end example
The following example spawns a new shell set up for the development of
GNU@tie{}Guile:
@example
guix environment guile
@end example
If the specified packages are not built yet, @command{guix environment}
automatically builds them. The new shell's environment is an augmented
version of the environment that @command{guix environment} was run in.
It contains the necessary search paths for building the given package
added to the existing environment variables. To create a ``pure''
environment in which the original environment variables have been unset,
use the @code{--pure} option@footnote{Users sometimes wrongfully augment
environment variables such as @code{PATH} in their @file{~/.bashrc}
file. As a consequence, when @code{guix environment} launches it, Bash
may read @file{~/.bashrc}, thereby introducing ``impurities'' in these
environment variables. It is an error to define such environment
variables in @file{.bashrc}; instead, they should be defined in
@file{.bash_profile}, which is sourced only by log-in shells.
@xref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}, for
details on Bash start-up files.}.
@vindex GUIX_ENVIRONMENT
@command{guix environment} defines the @code{GUIX_ENVIRONMENT}
variable in the shell it spaws. This allows users to, say, define a
specific prompt for development environments in their @file{.bashrc}
(@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
@example
if [ -n "$GUIX_ENVIRONMENT" ]
then
export PS1="\u@@\h \w [dev]\$ "
fi
@end example
Additionally, more than one package may be specified, in which case the
union of the inputs for the given packages are used. For example, the
command below spawns a shell where all of the dependencies of both Guile
and Emacs are available:
@example
guix environment guile emacs
@end example
Sometimes an interactive shell session is not desired. An arbitrary
command may be invoked by placing the @code{--} token to separate the
command from the rest of the arguments:
@example
guix environment guile -- make -j4
@end example
In other situations, it is more convenient to specify the list of
packages needed in the environment. For example, the following command
runs @command{python} from an environment containing Python@tie{}2.7 and
NumPy:
@example
guix environment --ad-hoc python2-numpy python-2.7 -- python
@end example
Furthermore, one might want the dependencies of a package and also some
additional packages that are not build-time or runtime dependencies, but
are useful when developing nonetheless. Because of this, the
@code{--ad-hoc} flag is positional. Packages appearing before
@code{--ad-hoc} are interpreted as packages whose dependencies will be
added to the environment. Packages appearing after are interpreted as
packages that will be added to the environment directly. For example,
the following command creates a Guix development environment that
additionally includes Git and strace:
@example
guix environment guix --ad-hoc git strace
@end example
Sometimes it is desirable to isolate the environment as much as
possible, for maximal purity and reproducibility. In particular, when
using Guix on a host distro that is not GuixSD, it is desirable to
prevent access to @file{/usr/bin} and other system-wide resources from
the development environment. For example, the following command spawns
a Guile REPL in a ``container'' where only the store and the current
working directory are mounted:
@example
guix environment --ad-hoc --container guile -- guile
@end example
@quotation Note
The @code{--container} option requires Linux-libre 3.19 or newer.
@end quotation
The available options are summarized below.
@table @code
@item --expression=@var{expr}
@itemx -e @var{expr}
Create an environment for the package or list of packages that
@var{expr} evaluates to.
For example, running:
@example
guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
@end example
starts a shell with the environment for this specific variant of the
PETSc package.
Running:
@example
guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
@end example
starts a shell with all the GuixSD base packages available.
@item --load=@var{file}
@itemx -l @var{file}
Create an environment for the package or list of packages that the code
within @var{file} evaluates to.
As an example, @var{file} might contain a definition like this
(@pxref{Defining Packages}):
@example
@verbatiminclude environment-gdb.scm
@end example
@item --ad-hoc
Include all specified packages in the resulting environment, as if an
@i{ad hoc} package were defined with them as inputs. This option is
useful for quickly creating an environment without having to write a
package expression to contain the desired inputs.
For instance, the command:
@example
guix environment --ad-hoc guile guile-sdl -- guile
@end example
runs @command{guile} in an environment where Guile and Guile-SDL are
available.
Note that this example implicitly asks for the default output of
@code{guile} and @code{guile-sdl} but it is possible to ask for a
specific output---e.g., @code{glib:bin} asks for the @code{bin} output
of @code{glib} (@pxref{Packages with Multiple Outputs}).
This option may be composed with the default behavior of @command{guix
environment}. Packages appearing before @code{--ad-hoc} are interpreted
as packages whose dependencies will be added to the environment, the
default behavior. Packages appearing after are interpreted as packages
that will be added to the environment directly.
@item --pure
Unset existing environment variables when building the new environment.
This has the effect of creating an environment in which search paths
only contain package inputs.
@item --search-paths
Display the environment variable definitions that make up the
environment.
@item --system=@var{system}
@itemx -s @var{system}
Attempt to build for @var{system}---e.g., @code{i686-linux}.
@item --container
@itemx -C
@cindex container
Run @var{command} within an isolated container. The current working
directory outside the container is mapped inside the
container. Additionally, the spawned process runs as the current user
outside the container, but has root privileges in the context of the
container.
@item --network
@itemx -N
For containers, share the network namespace with the host system.
Containers created without this flag only have access to the loopback
device.
@item --expose=@var{source}[=@var{target}]
For containers, expose the file system @var{source} from the host system
as the read-only file system @var{target} within the container. If
@var{target} is not specified, @var{source} is used as the target mount
point in the container.
The example below spawns a Guile REPL in a container in which the user's
home directory is accessible read-only via the @file{/exchange}
directory:
@example
guix environment --container --expose=$HOME=/exchange guile -- guile
@end example
@item --share=@var{source}[=@var{target}]
For containers, share the file system @var{source} from the host system
as the writable file system @var{target} within the container. If
@var{target} is not specified, @var{source} is used as the target mount
point in the container.
The example below spawns a Guile REPL in a container in which the user's
home directory is accessible for both reading and writing via the
@file{/exchange} directory:
@example
guix environment --container --share=$HOME=/exchange guile -- guile
@end example
@end table
It also supports all of the common build options that @command{guix
build} supports (@pxref{Invoking guix build, common build options}).
@node Invoking guix publish
@section Invoking @command{guix publish}
The purpose of @command{guix publish} is to enable users to easily share
their store with others, which can then use it as a substitute server
(@pxref{Substitutes}).
When @command{guix publish} runs, it spawns an HTTP server which allows
anyone with network access to obtain substitutes from it. This means
that any machine running Guix can also act as if it were a build farm,
since the HTTP interface is compatible with Hydra, the software behind
the @code{hydra.gnu.org} build farm.
For security, each substitute is signed, allowing recipients to check
their authenticity and integrity (@pxref{Substitutes}). Because
@command{guix publish} uses the system's signing key, which is only
readable by the system administrator, it must be started as root; the
@code{--user} option makes it drop root privileges early on.
The signing key pair must be generated before @command{guix publish} is
launched, using @command{guix archive --generate-key} (@pxref{Invoking
guix archive}).
The general syntax is:
@example
guix publish @var{options}@dots{}
@end example
Running @command{guix publish} without any additional arguments will
spawn an HTTP server on port 8080:
@example
guix publish
@end example
Once a publishing server has been authorized (@pxref{Invoking guix
archive}), the daemon may download substitutes from it:
@example
guix-daemon --substitute-urls=http://example.org:8080
@end example
The following options are available:
@table @code
@item --port=@var{port}
@itemx -p @var{port}
Listen for HTTP requests on @var{port}.
@item --listen=@var{host}
Listen on the network interface for @var{host}. The default is to
accept connections from any interface.
@item --user=@var{user}
@itemx -u @var{user}
Change privileges to @var{user} as soon as possible---i.e., once the
server socket is open and the signing key has been read.
@item --repl[=@var{port}]
@itemx -r [@var{port}]
Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
Reference Manual}) on @var{port} (37146 by default). This is used
primarily for debugging a running @command{guix publish} server.
@end table
Enabling @command{guix publish} on a GuixSD system is a one-liner: just
add a call to @code{guix-publish-service} in the @code{services} field
of the @code{operating-system} declaration (@pxref{guix-publish-service,
@code{guix-publish-service}}).
@node Invoking guix challenge
@section Invoking @command{guix challenge}
@cindex reproducible builds
@cindex verifiable builds
Do the binaries provided by this server really correspond to the source
code it claims to build? Is this package's build process deterministic?
These are the questions the @command{guix challenge} command attempts to
answer.
The former is obviously an important question: Before using a substitute
server (@pxref{Substitutes}), you'd rather @emph{verify} that it
provides the right binaries, and thus @emph{challenge} it. The latter
is what enables the former: If package builds are deterministic, then
independent builds of the package should yield the exact same result,
bit for bit; if a server provides a binary different from the one
obtained locally, it may be either corrupt or malicious.
We know that the hash that shows up in @file{/gnu/store} file names is
the hash of all the inputs of the process that built the file or
directory---compilers, libraries, build scripts,
etc. (@pxref{Introduction}). Assuming deterministic build processes,
one store file name should map to exactly one build output.
@command{guix challenge} checks whether there is, indeed, a single
mapping by comparing the build outputs of several independent builds of
any given store item.
The command's output looks like this:
@smallexample
$ guix challenge --substitute-urls="http://hydra.gnu.org http://guix.example.org"
updating list of substitutes from 'http://hydra.gnu.org'... 100.0%
updating list of substitutes from 'http://guix.example.org'... 100.0%
/gnu/store/@dots{}-openssl-1.0.2d contents differ:
local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
http://hydra.gnu.org/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
http://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
/gnu/store/@dots{}-git-2.5.0 contents differ:
local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
http://hydra.gnu.org/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
http://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
/gnu/store/@dots{}-pius-2.1.1 contents differ:
local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
http://hydra.gnu.org/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
http://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
@end smallexample
@noindent
In this example, @command{guix challenge} first scans the store to
determine the set of locally-built derivations---as opposed to store
items that were downloaded from a substitute server---and then queries
all the substitute servers. It then reports those store items for which
the servers obtained a result different from the local build.
@cindex non-determinism, in package builds
As an example, @code{guix.example.org} always gets a different answer.
Conversely, @code{hydra.gnu.org} agrees with local builds, except in the
case of Git. This might indicate that the build process of Git is
non-deterministic, meaning that its output varies as a function of
various things that Guix does not fully control, in spite of building
packages in isolated environments (@pxref{Features}). Most common
sources of non-determinism include the addition of timestamps in build
results, the inclusion of random numbers, and directory listings sorted
by inode number. See @uref{http://reproducible.debian.net/howto/}, for
more information.
To find out what's wrong with this Git binary, we can do something along
these lines (@pxref{Invoking guix archive}):
@example
$ wget -q -O - http://hydra.gnu.org/nar/@dots{}-git-2.5.0 \
| guix archive -x /tmp/git
$ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
@end example
This command shows the difference between the files resulting from the
local build, and the files resulting from the build on
@code{hydra.gnu.org} (@pxref{Overview, Comparing and Merging Files,,
diffutils, Comparing and Merging Files}). The @command{diff} command
works great for text files. When binary files differ, a better option
is @uref{http://diffoscope.org/, Diffoscope}, a tool that helps
visualize differences for all kinds of files.
Once you've done that work, you can tell whether the differences are due
to a non-deterministic build process or to a malicious server. We try
hard to remove sources of non-determinism in packages to make it easier
to verify substitutes, but of course, this is a process, one that
involves not just Guix but a large part of the free software community.
In the meantime, @command{guix challenge} is one tool to help address
the problem.
If you are writing packages for Guix, you are encouraged to check
whether @code{hydra.gnu.org} and other substitute servers obtain the
same build result as you did with:
@example
$ guix challenge @var{package}
@end example
@noindent
... where @var{package} is a package specification such as
@code{guile-2.0} or @code{glibc:debug}.
The general syntax is:
@example
guix challenge @var{options} [@var{packages}@dots{}]
@end example
The one option that matters is:
@table @code
@item --substitute-urls=@var{urls}
Consider @var{urls} the whitespace-separated list of substitute source
URLs to compare to.
@end table
@node Invoking guix container
@section Invoking @command{guix container}
@cindex container
@quotation Note
As of version @value{VERSION}, this tool is experimental. The interface
is subject to radical change in the future.
@end quotation
The purpose of @command{guix container} is to manipulate processes
running within an isolated environment, commonly known as a
``container'', typically created by the @command{guix environment}
(@pxref{Invoking guix environment}) and @command{guix system container}
(@pxref{Invoking guix system}) commands.
The general syntax is:
@example
guix container @var{action} @var{options}@dots{}
@end example
@var{action} specifies the operation to perform with a container, and
@var{options} specifies the context-specific arguments for the action.
The following actions are available:
@table @code
@item exec
Execute a command within the context of a running container.
The syntax is:
@example
guix container exec @var{pid} @var{program} @var{arguments}@dots{}
@end example
@var{pid} specifies the process ID of the running container.
@var{program} specifies an executable file name within the container's
root file system. @var{arguments} are the additional options that will
be passed to @var{program}.
The following command launches an interactive login shell inside a
GuixSD container, started by @command{guix system container}, and whose
process ID is 9001:
@example
guix container exec 9001 /run/current-system/profile/bin/bash --login
@end example
Note that the @var{pid} cannot be the parent process of a container. It
must be the container's PID 1 or one of its child processes.
@end table
@c *********************************************************************
@node GNU Distribution
@chapter GNU Distribution
@cindex Guix System Distribution
@cindex GuixSD
Guix comes with a distribution of the GNU system consisting entirely of
free software@footnote{The term ``free'' here refers to the
@url{http://www.gnu.org/philosophy/free-sw.html,freedom provided to
users of that software}.}. The
distribution can be installed on its own (@pxref{System Installation}),
but it is also possible to install Guix as a package manager on top of
an installed GNU/Linux system (@pxref{Installation}). To distinguish
between the two, we refer to the standalone distribution as the Guix
System Distribution, or GuixSD.
The distribution provides core GNU packages such as GNU libc, GCC, and
Binutils, as well as many GNU and non-GNU applications. The complete
list of available packages can be browsed
@url{http://www.gnu.org/software/guix/packages,on-line} or by
running @command{guix package} (@pxref{Invoking guix package}):
@example
guix package --list-available
@end example
Our goal has been to provide a practical 100% free software distribution of
Linux-based and other variants of GNU, with a focus on the promotion and
tight integration of GNU components, and an emphasis on programs and
tools that help users exert that freedom.
Packages are currently available on the following platforms:
@table @code
@item x86_64-linux
Intel/AMD @code{x86_64} architecture, Linux-Libre kernel;
@item i686-linux
Intel 32-bit architecture (IA32), Linux-Libre kernel;
@item armhf-linux
ARMv7-A architecture with hard float, Thumb-2 and NEON,
using the EABI hard-float ABI, and Linux-Libre kernel.
@item mips64el-linux
little-endian 64-bit MIPS processors, specifically the Loongson series,
n32 application binary interface (ABI), and Linux-Libre kernel.
@end table
GuixSD itself is currently only available on @code{i686} and @code{x86_64}.
@noindent
For information on porting to other architectures or kernels,
@xref{Porting}.
@menu
* System Installation:: Installing the whole operating system.
* System Configuration:: Configuring the operating system.
* Installing Debugging Files:: Feeding the debugger.
* Security Updates:: Deploying security fixes quickly.
* Package Modules:: Packages from the programmer's viewpoint.
* Packaging Guidelines:: Growing the distribution.
* Bootstrapping:: GNU/Linux built from scratch.
* Porting:: Targeting another platform or kernel.
@end menu
Building this distribution is a cooperative effort, and you are invited
to join! @xref{Contributing}, for information about how you can help.
@node System Installation
@section System Installation
@cindex Guix System Distribution
This section explains how to install the Guix System Distribution
on a machine. The Guix package manager can
also be installed on top of a running GNU/Linux system,
@pxref{Installation}.
@ifinfo
@c This paragraph is for people reading this from tty2 of the
@c installation image.
You're reading this documentation with an Info reader. For details on
how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
link that follows: @pxref{Help,,, info, Info: An Introduction}. Hit
@kbd{l} afterwards to come back here.
@end ifinfo
@subsection Limitations
As of version @value{VERSION}, the Guix System Distribution (GuixSD) is
not production-ready. It may contain bugs and lack important
features. Thus, if you are looking for a stable production system that
respects your freedom as a computer user, a good solution at this point
is to consider @url{http://www.gnu.org/distros/free-distros.html, one of
more established GNU/Linux distributions}. We hope you can soon switch
to the GuixSD without fear, of course. In the meantime, you can
also keep using your distribution and try out the package manager on top
of it (@pxref{Installation}).
Before you proceed with the installation, be aware of the following
noteworthy limitations applicable to version @value{VERSION}:
@itemize
@item
The installation process does not include a graphical user interface and
requires familiarity with GNU/Linux (see the following subsections to
get a feel of what that means.)
@item
The system does not yet provide full GNOME and KDE desktops. Xfce and
Enlightenment are available though, if graphical desktop environments
are your thing, as well as a number of X11 window managers.
@item
Support for the Logical Volume Manager (LVM) is missing.
@item
Few system services are currently supported out-of-the-box
(@pxref{Services}).
@item
More than 2,000 packages are available, but you may
occasionally find that a useful package is missing.
@end itemize
You've been warned. But more than a disclaimer, this is an invitation
to report issues (and success stories!), and join us in improving it.
@xref{Contributing}, for more info.
@subsection USB Stick Installation
An installation image for USB sticks can be downloaded from
@indicateurl{ftp://alpha.gnu.org/gnu/guix/guixsd-usb-install-@value{VERSION}.@var{system}.xz},
where @var{system} is one of:
@table @code
@item x86_64-linux
for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
@item i686-linux
for a 32-bit GNU/Linux system on Intel-compatible CPUs.
@end table
This image contains a single partition with the tools necessary for an
installation. It is meant to be copied @emph{as is} to a large-enough
USB stick.
To copy the image to a USB stick, follow these steps:
@enumerate
@item
Decompress the image using the @command{xz} command:
@example
xz -d guixsd-usb-install-@value{VERSION}.@var{system}.xz
@end example
@item
Insert a USB stick of 1@tie{}GiB or more in your machine, and determine
its device name. Assuming that USB stick is known as @file{/dev/sdX},
copy the image with:
@example
dd if=guixsd-usb-install-@value{VERSION}.x86_64 of=/dev/sdX
@end example
Access to @file{/dev/sdX} usually requires root privileges.
@end enumerate
Once this is done, you should be able to reboot the system and boot from
the USB stick. The latter usually requires you to get in the BIOS' boot
menu, where you can choose to boot from the USB stick.
@subsection Preparing for Installation
Once you have successfully booted the image on the USB stick, you should
end up with a root prompt. Several console TTYs are configured and can
be used to run commands as root. TTY2 shows this documentation,
browsable using the Info reader commands (@pxref{Help,,, info, Info: An
Introduction}). The installation system runs the GPM mouse daemon,
which allows you to select text with the left mouse button and to paste
it with the middle button.
To install the system, you would:
@enumerate
@item
Configure the network, by running:
@example
ifconfig eno1 up && dhclient eno1
@end example
to get an automatically assigned IP address from the wired
network interface controller@footnote{
@c http://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
The name @code{eno1} is for the first on-board Ethernet controller. The
interface name for an Ethernet controller that is in the first slot of
the first PCI bus, for instance, would be @code{enp1s0}. Use
@command{ifconfig -a} to list all the available network interfaces.},
or using the @command{ifconfig} command.
The system automatically loads drivers for your network interface
controllers.
Setting up network access is almost always a requirement because the
image does not contain all the software and tools that may be needed.
@item
Unless this has already been done, you must partition, and then format
the target partition.
Preferably, assign partitions a label so that you can easily and
reliably refer to them in @code{file-system} declarations (@pxref{File
Systems}). This is typically done using the @code{-L} option of
@command{mkfs.ext4} and related commands.
Be sure that your partition labels match the value of their respective
@code{device} fields in your @code{file-system} configuration, if your
@code{file-system} configuration sets the value of @code{title} to
@code{'label}, as do the example configurations found on the USB
installation image under @file{/etc/configuration} (@pxref{Using the
Configuration System}).
@c FIXME: Uncomment this once GRUB fully supports encrypted roots.
@c A typical command sequence may be:
@c
@c @example
@c # fdisk /dev/sdX
@c @dots{} Create partitions etc.@dots{}
@c # cryptsetup luksFormat /dev/sdX1
@c # cryptsetup open --type luks /dev/sdX1 my-partition
@c # mkfs.ext4 -L my-root /dev/mapper/my-partition
@c @end example
The installation image includes Parted (@pxref{Overview,,, parted, GNU
Parted User Manual}), @command{fdisk}, Cryptsetup/LUKS for disk
encryption, and e2fsprogs, the suite of tools to manipulate
ext2/ext3/ext4 file systems.
@item
Once that is done, mount the target root partition under @file{/mnt}.
@item
Lastly, run @code{deco start cow-store /mnt}.
This will make @file{/gnu/store} copy-on-write, such that packages added
to it during the installation phase will be written to the target disk
rather than kept in memory.
@end enumerate
@subsection Proceeding with the Installation
With the target partitions ready, you now have to edit a file and
provide the declaration of the operating system to be installed. To
that end, the installation system comes with two text editors: GNU nano
(@pxref{Top,,, nano, GNU nano Manual}), and GNU Zile, an Emacs clone.
It is better to store that file on the target root file system, say, as
@file{/mnt/etc/config.scm}.
@xref{Using the Configuration System}, for examples of operating system
configurations. These examples are available under
@file{/etc/configuration} in the installation image, so you can copy
them and use them as a starting point for your own configuration.
Once you are done preparing the configuration file, the new system must
be initialized (remember that the target root file system is mounted
under @file{/mnt}):
@example
guix system init /mnt/etc/config.scm /mnt
@end example
@noindent
This will copy all the necessary files, and install GRUB on
@file{/dev/sdX}, unless you pass the @option{--no-grub} option. For
more information, @pxref{Invoking guix system}. This command may trigger
downloads or builds of missing packages, which can take some time.
Once that command has completed---and hopefully succeeded!---you can run
@command{reboot} and boot into the new system. The @code{root} password
in the new system is initially empty; other users' passwords need to be
initialized by running the @command{passwd} command as @code{root},
unless your configuration specifies otherwise
(@pxref{user-account-password, user account passwords}).
Join us on @code{#guix} on the Freenode IRC network or on
@file{guix-devel@@gnu.org} to share your experience---good or not so
good.
@subsection Building the Installation Image
The installation image described above was built using the @command{guix
system} command, specifically:
@example
guix system disk-image --image-size=850MiB gnu/system/install.scm
@end example
@xref{Invoking guix system}, for more information. See
@file{gnu/system/install.scm} in the source tree for more information
about the installation image.
@node System Configuration
@section System Configuration
@cindex system configuration
The Guix System Distribution supports a consistent whole-system configuration
mechanism. By that we mean that all aspects of the global system
configuration---such as the available system services, timezone and
locale settings, user accounts---are declared in a single place. Such
a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
One of the advantages of putting all the system configuration under the
control of Guix is that it supports transactional system upgrades, and
makes it possible to roll-back to a previous system instantiation,
should something go wrong with the new one (@pxref{Features}). Another
one is that it makes it easy to replicate the exact same configuration
across different machines, or at different points in time, without
having to resort to additional administration tools layered on top of
the system's own tools.
@c Yes, we're talking of Puppet, Chef, & co. here. ↑
This section describes this mechanism. First we focus on the system
administrator's viewpoint---explaining how the system is configured and
instantiated. Then we show how this mechanism can be extended, for
instance to support new system services.
@menu
* Using the Configuration System:: Customizing your GNU system.
* operating-system Reference:: Detail of operating-system declarations.
* File Systems:: Configuring file system mounts.
* Mapped Devices:: Block device extra processing.
* User Accounts:: Specifying user accounts.
* Locales:: Language and cultural convention settings.
* Services:: Specifying system services.
* Setuid Programs:: Programs running with root privileges.
* X.509 Certificates:: Authenticating HTTPS servers.
* Name Service Switch:: Configuring libc's name service switch.
* Initial RAM Disk:: Linux-Libre bootstrapping.
* GRUB Configuration:: Configuring the boot loader.
* Invoking guix system:: Instantiating a system configuration.
* Running GuixSD in a VM:: How to run GuixSD in a virtual machine.
* Defining Services:: Adding new service definitions.
@end menu
@node Using the Configuration System
@subsection Using the Configuration System
The operating system is configured by providing an
@code{operating-system} declaration in a file that can then be passed to
the @command{guix system} command (@pxref{Invoking guix system}). A
simple setup, with the default system services, the default Linux-Libre
kernel, initial RAM disk, and boot loader looks like this:
@findex operating-system
@lisp
@include os-config-bare-bones.texi
@end lisp
This example should be self-describing. Some of the fields defined
above, such as @code{host-name} and @code{bootloader}, are mandatory.
Others, such as @code{packages} and @code{services}, can be omitted, in
which case they get a default value.
Below we discuss the effect of some of the most important fields
(@pxref{operating-system Reference}, for details about all the available
fields), and how to @dfn{instantiate} the operating system using
@command{guix system}.
@unnumberedsubsubsec Globally-Visible Packages
@vindex %base-packages
The @code{packages} field lists packages that will be globally visible
on the system, for all user accounts---i.e., in every user's @code{PATH}
environment variable---in addition to the per-user profiles
(@pxref{Invoking guix package}). The @var{%base-packages} variable
provides all the tools one would expect for basic user and administrator
tasks---including the GNU Core Utilities, the GNU Networking Utilities,
the GNU Zile lightweight text editor, @command{find}, @command{grep},
etc. The example above adds tcpdump to those, taken from the @code{(gnu
packages admin)} module (@pxref{Package Modules}).
@findex specification->package
Referring to packages by variable name, like @var{tcpdump} above, has
the advantage of being unambiguous; it also allows typos and such to be
diagnosed right away as ``unbound variables''. The downside is that one
needs to know which module defines which package, and to augment the
@code{use-package-modules} line accordingly. To avoid that, one can use
the @code{specification->package} procedure of the @code{(gnu packages)}
module, which returns the best package for a given name or name and
version:
@lisp
(use-modules (gnu packages))
(operating-system
;; ...
(packages (append (map specification->package
'("tcpdump" "htop" "gnupg-2.0"))
%base-packages)))
@end lisp
@unnumberedsubsubsec System Services
@vindex %base-services
The @code{services} field lists @dfn{system services} to be made
available when the system starts (@pxref{Services}).
The @code{operating-system} declaration above specifies that, in
addition to the basic services, we want the @command{lshd} secure shell
daemon listening on port 2222 (@pxref{Networking Services,
@code{lsh-service}}). Under the hood,
@code{lsh-service} arranges so that @code{lshd} is started with the
right command-line options, possibly with supporting configuration files
generated as needed (@pxref{Defining Services}).
@cindex customization, of services
@findex modify-services
Occasionally, instead of using the base services as is, you will want to
customize them. For instance, to change the configuration of
@code{guix-daemon} and Mingetty (the console log-in), you may write the
following instead of @var{%base-services}:
@lisp
(modify-services %base-services
(guix-service-type config =>
(guix-configuration
(inherit config)
(use-substitutes? #f)
(extra-options '("--gc-keep-outputs"))))
(mingetty-service-type config =>
(mingetty-configuration
(inherit config)
(motd (plain-file "motd" "Hi there!")))))
@end lisp
@noindent
The effect here is to change the options passed to @command{guix-daemon}
when it is started, as well as the ``message of the day'' that appears
when logging in at the console. @xref{Service Reference,
@code{modify-services}}, for more on that.
The configuration for a typical ``desktop'' usage, with the X11 display
server, a desktop environment, network management, power management, and
more, would look like this:
@lisp
@include os-config-desktop.texi
@end lisp
@xref{Desktop Services}, for the exact list of services provided by
@var{%desktop-services}. @xref{X.509 Certificates}, for background
information about the @code{nss-certs} package that is used here.
Again, @var{%desktop-services} is just a list of service objects. If
you want to remove services from there, you can do so using the
procedures for list filtering (@pxref{SRFI-1 Filtering and
Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
following expression returns a list that contains all the services in
@var{%desktop-services} minus the Avahi service:
@example
(remove (lambda (service)
(eq? (service-kind service) avahi-service-type))
%desktop-services)
@end example
@unnumberedsubsubsec Instantiating the System
Assuming the @code{operating-system} declaration
is stored in the @file{my-system-config.scm}
file, the @command{guix system reconfigure my-system-config.scm} command
instantiates that configuration, and makes it the default GRUB boot
entry (@pxref{Invoking guix system}).
The normal way to change the system's configuration is by updating this
file and re-running @command{guix system reconfigure}. One should never
have to touch files in @command{/etc} or to run commands that modify the
system state such as @command{useradd} or @command{grub-install}. In
fact, you must avoid that since that would not only void your warranty
but also prevent you from rolling back to previous versions of your
system, should you ever need to.
@cindex roll-back, of the operating system
Speaking of roll-back, each time you run @command{guix system
reconfigure}, a new @dfn{generation} of the system is created---without
modifying or deleting previous generations. Old system generations get
an entry in the GRUB boot menu, allowing you to boot them in case
something went wrong with the latest generation. Reassuring, no? The
@command{guix system list-generations} command lists the system
generations available on disk.
@unnumberedsubsubsec The Programming Interface
At the Scheme level, the bulk of an @code{operating-system} declaration
is instantiated with the following monadic procedure (@pxref{The Store
Monad}):
@deffn {Monadic Procedure} operating-system-derivation os
Return a derivation that builds @var{os}, an @code{operating-system}
object (@pxref{Derivations}).
The output of the derivation is a single directory that refers to all
the packages, configuration files, and other supporting files needed to
instantiate @var{os}.
@end deffn
This procedure is provided by the @code{(gnu system)} module. Along
with @code{(gnu services)} (@pxref{Services}), this module contains the
guts of GuixSD. Make sure to visit it!
@node operating-system Reference
@subsection @code{operating-system} Reference
This section summarizes all the options available in
@code{operating-system} declarations (@pxref{Using the Configuration
System}).
@deftp {Data Type} operating-system
This is the data type representing an operating system configuration.
By that, we mean all the global system configuration, not per-user
configuration (@pxref{Using the Configuration System}).
@table @asis
@item @code{kernel} (default: @var{linux-libre})
The package object of the operating system kernel to use@footnote{Currently
only the Linux-libre kernel is supported. In the future, it will be
possible to use the GNU@tie{}Hurd.}.
@item @code{kernel-arguments} (default: @code{'()})
List of strings or gexps representing additional arguments to pass on
the kernel's command-line---e.g., @code{("console=ttyS0")}.
@item @code{bootloader}
The system bootloader configuration object. @xref{GRUB Configuration}.
@item @code{initrd} (default: @code{base-initrd})
A two-argument monadic procedure that returns an initial RAM disk for
the Linux kernel. @xref{Initial RAM Disk}.
@item @code{firmware} (default: @var{%base-firmware})
@cindex firmware
List of firmware packages loadable by the operating system kernel.
The default includes firmware needed for Atheros-based WiFi devices
(Linux-libre module @code{ath9k}.)
@item @code{host-name}
The host name.
@item @code{hosts-file}
@cindex hosts file
A file-like object (@pxref{G-Expressions, file-like objects}) for use as
@file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
Reference Manual}). The default is a file with entries for
@code{localhost} and @var{host-name}.
@item @code{mapped-devices} (default: @code{'()})
A list of mapped devices. @xref{Mapped Devices}.
@item @code{file-systems}
A list of file systems. @xref{File Systems}.
@item @code{swap-devices} (default: @code{'()})
@cindex swap devices
A list of strings identifying devices to be used for ``swap space''
(@pxref{Memory Concepts,,, libc, The GNU C Library Reference Manual}).
For example, @code{'("/dev/sda3")}.
@item @code{users} (default: @code{%base-user-accounts})
@itemx @code{groups} (default: @var{%base-groups})
List of user accounts and groups. @xref{User Accounts}.
@item @code{skeletons} (default: @code{(default-skeletons)})
A monadic list of pairs of target file name and files. These are the
files that will be used as skeletons as new accounts are created.
For instance, a valid value may look like this:
@example
(mlet %store-monad ((bashrc (text-file "bashrc" "\
export PATH=$HOME/.guix-profile/bin")))
(return `((".bashrc" ,bashrc))))
@end example
@item @code{issue} (default: @var{%default-issue})
A string denoting the contents of the @file{/etc/issue} file, which is
what displayed when users log in on a text console.
@item @code{packages} (default: @var{%base-packages})
The set of packages installed in the global profile, which is accessible
at @file{/run/current-system/profile}.
The default set includes core utilities, but it is good practice to
install non-core utilities in user profiles (@pxref{Invoking guix
package}).
@item @code{timezone}
A timezone identifying string---e.g., @code{"Europe/Paris"}.
@item @code{locale} (default: @code{"en_US.utf8"})
The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
Library Reference Manual}). @xref{Locales}, for more information.
@item @code{locale-definitions} (default: @var{%default-locale-definitions})
The list of locale definitions to be compiled and that may be used at
run time. @xref{Locales}.
@item @code{locale-libcs} (default: @code{(list @var{glibc})})
The list of GNU@tie{}libc packages whose locale data and tools are used
to build the locale definitions. @xref{Locales}, for compatibility
considerations that justify this option.
@item @code{name-service-switch} (default: @var{%default-nss})
Configuration of libc's name service switch (NSS)---a
@code{<name-service-switch>} object. @xref{Name Service Switch}, for
details.
@item @code{services} (default: @var{%base-services})
A list of service objects denoting system services. @xref{Services}.
@item @code{pam-services} (default: @code{(base-pam-services)})
@cindex PAM
@cindex pluggable authentication modules
Linux @dfn{pluggable authentication module} (PAM) services.
@c FIXME: Add xref to PAM services section.
@item @code{setuid-programs} (default: @var{%setuid-programs})
List of string-valued G-expressions denoting setuid programs.
@xref{Setuid Programs}.
@item @code{sudoers-file} (default: @var{%sudoers-specification})
@cindex sudoers file
The contents of the @file{/etc/sudoers} file as a file-like object
(@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
This file specifies which users can use the @command{sudo} command, what
they are allowed to do, and what privileges they may gain. The default
is that only @code{root} and members of the @code{wheel} group may use
@code{sudo}.
@end table
@end deftp
@node File Systems
@subsection File Systems
The list of file systems to be mounted is specified in the
@code{file-systems} field of the operating system's declaration
(@pxref{Using the Configuration System}). Each file system is declared
using the @code{file-system} form, like this:
@example
(file-system
(mount-point "/home")
(device "/dev/sda3")
(type "ext4"))
@end example
As usual, some of the fields are mandatory---those shown in the example
above---while others can be omitted. These are described below.
@deftp {Data Type} file-system
Objects of this type represent file systems to be mounted. They
contain the following members:
@table @asis
@item @code{type}
This is a string specifying the type of the file system---e.g.,
@code{"ext4"}.
@item @code{mount-point}
This designates the place where the file system is to be mounted.
@item @code{device}
This names the ``source'' of the file system. By default it is the name
of a node under @file{/dev}, but its meaning depends on the @code{title}
field described below.
@item @code{title} (default: @code{'device})
This is a symbol that specifies how the @code{device} field is to be
interpreted.
When it is the symbol @code{device}, then the @code{device} field is
interpreted as a file name; when it is @code{label}, then @code{device}
is interpreted as a partition label name; when it is @code{uuid},
@code{device} is interpreted as a partition unique identifier (UUID).
UUIDs may be converted from their string representation (as shown by the
@command{tune2fs -l} command) using the @code{uuid} form, like this:
@example
(file-system
(mount-point "/home")
(type "ext4")
(title 'uuid)
(device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
@end example
The @code{label} and @code{uuid} options offer a way to refer to disk
partitions without having to hard-code their actual device
name@footnote{Note that, while it is tempting to use
@file{/dev/disk/by-uuid} and similar device names to achieve the same
result, this is not recommended: These special device nodes are created
by the udev daemon and may be unavailable at the time the device is
mounted.}.
However, when a file system's source is a mapped device (@pxref{Mapped
Devices}), its @code{device} field @emph{must} refer to the mapped
device name---e.g., @file{/dev/mapper/root-partition}---and consequently
@code{title} must be set to @code{'device}. This is required so that
the system knows that mounting the file system depends on having the
corresponding device mapping established.
@item @code{flags} (default: @code{'()})
This is a list of symbols denoting mount flags. Recognized flags
include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
access to special files), @code{no-suid} (ignore setuid and setgid
bits), and @code{no-exec} (disallow program execution.)
@item @code{options} (default: @code{#f})
This is either @code{#f}, or a string denoting mount options.
@item @code{mount?} (default: @code{#t})
This value indicates whether to automatically mount the file system when
the system is brought up. When set to @code{#f}, the file system gets
an entry in @file{/etc/fstab} (read by the @command{mount} command) but
is not automatically mounted.
@item @code{needed-for-boot?} (default: @code{#f})
This Boolean value indicates whether the file system is needed when
booting. If that is true, then the file system is mounted when the
initial RAM disk (initrd) is loaded. This is always the case, for
instance, for the root file system.
@item @code{check?} (default: @code{#t})
This Boolean indicates whether the file system needs to be checked for
errors before being mounted.
@item @code{create-mount-point?} (default: @code{#f})
When true, the mount point is created if it does not exist yet.
@item @code{dependencies} (default: @code{'()})
This is a list of @code{<file-system>} objects representing file systems
that must be mounted before (and unmounted after) this one.
As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
a dependency of @file{/sys/fs/cgroup/cpu} and
@file{/sys/fs/cgroup/memory}.
@end table
@end deftp
The @code{(gnu system file-systems)} exports the following useful
variables.
@defvr {Scheme Variable} %base-file-systems
These are essential file systems that are required on normal systems,
such as @var{%pseudo-terminal-file-system} and @var{%immutable-store} (see
below.) Operating system declarations should always contain at least
these.
@end defvr
@defvr {Scheme Variable} %pseudo-terminal-file-system
This is the file system to be mounted as @file{/dev/pts}. It supports
@dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
Manual}). Pseudo-terminals are used by terminal emulators such as
@command{xterm}.
@end defvr
@defvr {Scheme Variable} %shared-memory-file-system
This file system is mounted as @file{/dev/shm} and is used to support
memory sharing across processes (@pxref{Memory-mapped I/O,
@code{shm_open},, libc, The GNU C Library Reference Manual}).
@end defvr
@defvr {Scheme Variable} %immutable-store
This file system performs a read-only ``bind mount'' of
@file{/gnu/store}, making it read-only for all the users including
@code{root}. This prevents against accidental modification by software
running as @code{root} or by system administrators.
The daemon itself is still able to write to the store: it remounts it
read-write in its own ``name space.''
@end defvr
@defvr {Scheme Variable} %binary-format-file-system
The @code{binfmt_misc} file system, which allows handling of arbitrary
executable file types to be delegated to user space. This requires the
@code{binfmt.ko} kernel module to be loaded.
@end defvr
@defvr {Scheme Variable} %fuse-control-file-system
The @code{fusectl} file system, which allows unprivileged users to mount
and unmount user-space FUSE file systems. This requires the
@code{fuse.ko} kernel module to be loaded.
@end defvr
@node Mapped Devices
@subsection Mapped Devices
@cindex device mapping
@cindex mapped devices
The Linux kernel has a notion of @dfn{device mapping}: a block device,
such as a hard disk partition, can be @dfn{mapped} into another device,
with additional processing over the data that flows through
it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
concept of a ``mapped device'' and that of a file system: both boil down
to @emph{translating} input/output operations made on a file to
operations on its backing store. Thus, the Hurd implements mapped
devices, like file systems, using the generic @dfn{translator} mechanism
(@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
typical example is encryption device mapping: all writes to the mapped
device are encrypted, and all reads are deciphered, transparently.
Mapped devices are declared using the @code{mapped-device} form:
@example
(mapped-device
(source "/dev/sda3")
(target "home")
(type luks-device-mapping))
@end example
@noindent
@cindex disk encryption
@cindex LUKS
This example specifies a mapping from @file{/dev/sda3} to
@file{/dev/mapper/home} using LUKS---the
@url{http://code.google.com/p/cryptsetup,Linux Unified Key Setup}, a
standard mechanism for disk encryption. The @file{/dev/mapper/home}
device can then be used as the @code{device} of a @code{file-system}
declaration (@pxref{File Systems}). The @code{mapped-device} form is
detailed below.
@deftp {Data Type} mapped-device
Objects of this type represent device mappings that will be made when
the system boots up.
@table @code
@item source
This string specifies the name of the block device to be mapped, such as
@code{"/dev/sda3"}.
@item target
This string specifies the name of the mapping to be established. For
example, specifying @code{"my-partition"} will lead to the creation of
the @code{"/dev/mapper/my-partition"} device.
@item type
This must be a @code{mapped-device-kind} object, which specifies how
@var{source} is mapped to @var{target}.
@end table
@end deftp
@defvr {Scheme Variable} luks-device-mapping
This defines LUKS block device encryption using the @command{cryptsetup}
command, from the same-named package. This relies on the
@code{dm-crypt} Linux kernel module.
@end defvr
@node User Accounts
@subsection User Accounts
User accounts and groups are entirely managed through the
@code{operating-system} declaration. They are specified with the
@code{user-account} and @code{user-group} forms:
@example
(user-account
(name "alice")
(group "users")
(supplementary-groups '("wheel" ;allow use of sudo, etc.
"audio" ;sound card
"video" ;video devices such as webcams
"cdrom")) ;the good ol' CD-ROM
(comment "Bob's sister")
(home-directory "/home/alice"))
@end example
When booting or upon completion of @command{guix system reconfigure},
the system ensures that only the user accounts and groups specified in
the @code{operating-system} declaration exist, and with the specified
properties. Thus, account or group creations or modifications made by
directly invoking commands such as @command{useradd} are lost upon
reconfiguration or reboot. This ensures that the system remains exactly
as declared.
@deftp {Data Type} user-account
Objects of this type represent user accounts. The following members may
be specified:
@table @asis
@item @code{name}
The name of the user account.
@item @code{group}
This is the name (a string) or identifier (a number) of the user group
this account belongs to.
@item @code{supplementary-groups} (default: @code{'()})
Optionally, this can be defined as a list of group names that this
account belongs to.
@item @code{uid} (default: @code{#f})
This is the user ID for this account (a number), or @code{#f}. In the
latter case, a number is automatically chosen by the system when the
account is created.
@item @code{comment} (default: @code{""})
A comment about the account, such as the account's owner full name.
@item @code{home-directory}
This is the name of the home directory for the account.
@item @code{shell} (default: Bash)
This is a G-expression denoting the file name of a program to be used as
the shell (@pxref{G-Expressions}).
@item @code{system?} (default: @code{#f})
This Boolean value indicates whether the account is a ``system''
account. System accounts are sometimes treated specially; for instance,
graphical login managers do not list them.
@anchor{user-account-password}
@item @code{password} (default: @code{#f})
You would normally leave this field to @code{#f}, initialize user
passwords as @code{root} with the @command{passwd} command, and then let
users change it with @command{passwd}. Passwords set with
@command{passwd} are of course preserved across reboot and
reconfiguration.
If you @emph{do} want to have a preset password for an account, then
this field must contain the encrypted password, as a string.
@xref{crypt,,, libc, The GNU C Library Reference Manual}, for more information
on password encryption, and @ref{Encryption,,, guile, GNU Guile Reference
Manual}, for information on Guile's @code{crypt} procedure.
@end table
@end deftp
User group declarations are even simpler:
@example
(user-group (name "students"))
@end example
@deftp {Data Type} user-group
This type is for, well, user groups. There are just a few fields:
@table @asis
@item @code{name}
The group's name.
@item @code{id} (default: @code{#f})
The group identifier (a number). If @code{#f}, a new number is
automatically allocated when the group is created.
@item @code{system?} (default: @code{#f})
This Boolean value indicates whether the group is a ``system'' group.
System groups have low numerical IDs.
@item @code{password} (default: @code{#f})
What, user groups can have a password? Well, apparently yes. Unless
@code{#f}, this field specifies the group's password.
@end table
@end deftp
For convenience, a variable lists all the basic user groups one may
expect:
@defvr {Scheme Variable} %base-groups
This is the list of basic user groups that users and/or packages expect
to be present on the system. This includes groups such as ``root'',
``wheel'', and ``users'', as well as groups used to control access to
specific devices such as ``audio'', ``disk'', and ``cdrom''.
@end defvr
@defvr {Scheme Variable} %base-user-accounts
This is the list of basic system accounts that programs may expect to
find on a GNU/Linux system, such as the ``nobody'' account.
Note that the ``root'' account is not included here. It is a
special-case and is automatically added whether or not it is specified.
@end defvr
@node Locales
@subsection Locales
@cindex locale
A @dfn{locale} defines cultural conventions for a particular language
and region of the world (@pxref{Locales,,, libc, The GNU C Library
Reference Manual}). Each locale has a name that typically has the form
@code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
@code{fr_LU.utf8} designates the locale for the French language, with
cultural conventions from Luxembourg, and using the UTF-8 encoding.
@cindex locale definition
Usually, you will want to specify the default locale for the machine
using the @code{locale} field of the @code{operating-system} declaration
(@pxref{operating-system Reference, @code{locale}}).
That locale must be among the @dfn{locale definitions} that are known to
the system---and these are specified in the @code{locale-definitions}
slot of @code{operating-system}. The default value includes locale
definitions for some widely used locales, but not for all the available
locales, in order to save space.
If the locale specified in the @code{locale} field is not among the
definitions listed in @code{locale-definitions}, @command{guix system}
raises an error. In that case, you should add the locale definition to
the @code{locale-definitions} field. For instance, to add the North
Frisian locale for Germany, the value of that field may be:
@example
(cons (locale-definition
(name "fy_DE.utf8") (source "fy_DE"))
%default-locale-definitions)
@end example
Likewise, to save space, one might want @code{locale-definitions} to
list only the locales that are actually used, as in:
@example
(list (locale-definition
(name "ja_JP.eucjp") (source "ja_JP")
(charset "EUC-JP")))
@end example
@vindex LOCPATH
The compiled locale definitions are available at
@file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
version, which is the default location where the GNU@tie{}libc provided
by Guix looks for locale data. This can be overridden using the
@code{LOCPATH} environment variable (@pxref{locales-and-locpath,
@code{LOCPATH} and locale packages}).
The @code{locale-definition} form is provided by the @code{(gnu system
locale)} module. Details are given below.
@deftp {Data Type} locale-definition
This is the data type of a locale definition.
@table @asis
@item @code{name}
The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
Reference Manual}, for more information on locale names.
@item @code{source}
The name of the source for that locale. This is typically the
@code{@var{language}_@var{territory}} part of the locale name.
@item @code{charset} (default: @code{"UTF-8"})
The ``character set'' or ``code set'' for that locale,
@uref{http://www.iana.org/assignments/character-sets, as defined by
IANA}.
@end table
@end deftp
@defvr {Scheme Variable} %default-locale-definitions
An arbitrary list of commonly used UTF-8 locales, used as the default
value of the @code{locale-definitions} field of @code{operating-system}
declarations.
@cindex locale name
@cindex normalized codeset in locale names
These locale definitions use the @dfn{normalized codeset} for the part
that follows the dot in the name (@pxref{Using gettextized software,
normalized codeset,, libc, The GNU C Library Reference Manual}). So for
instance it has @code{uk_UA.utf8} but @emph{not}, say,
@code{uk_UA.UTF-8}.
@end defvr
@subsubsection Locale Data Compatibility Considerations
@cindex incompatibility, of locale data
@code{operating-system} declarations provide a @code{locale-libcs} field
to specify the GNU@tie{}libc packages that are used to compile locale
declarations (@pxref{operating-system Reference}). ``Why would I
care?'', you may ask. Well, it turns out that the binary format of
locale data is occasionally incompatible from one libc version to
another.
@c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
@c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
For instance, a program linked against libc version 2.21 is unable to
read locale data produced with libc 2.22; worse, that program
@emph{aborts} instead of simply ignoring the incompatible locale
data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
the incompatible locale data, which is already an improvement.}.
Similarly, a program linked against libc 2.22 can read most, but not
all, the locale data from libc 2.21 (specifically, @code{LC_COLLATE}
data is incompatible); thus calls to @code{setlocale} may fail, but
programs will not abort.
The ``problem'' in GuixSD is that users have a lot of freedom: They can
choose whether and when to upgrade software in their profiles, and might
be using a libc version different from the one the system administrator
used to build the system-wide locale data.
Fortunately, unprivileged users can also install their own locale data
and define @var{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
@code{GUIX_LOCPATH} and locale packages}).
Still, it is best if the system-wide locale data at
@file{/run/current-system/locale} is built for all the libc versions
actually in use on the system, so that all the programs can access
it---this is especially crucial on a multi-user system. To do that, the
administrator can specify several libc packages in the
@code{locale-libcs} field of @code{operating-system}:
@example
(use-package-modules base)
(operating-system
;; @dots{}
(locale-libcs (list glibc-2.21 (canonical-package glibc))))
@end example
This example would lead to a system containing locale definitions for
both libc 2.21 and the current version of libc in
@file{/run/current-system/locale}.
@node Services
@subsection Services
@cindex system services
An important part of preparing an @code{operating-system} declaration is
listing @dfn{system services} and their configuration (@pxref{Using the
Configuration System}). System services are typically daemons launched
when the system boots, or other actions needed at that time---e.g.,
configuring network access.
Services are managed by GNU@tie{}dmd (@pxref{Introduction,,, dmd, GNU
dmd Manual}). On a running system, the @command{deco} command allows
you to list the available services, show their status, start and stop
them, or do other specific operations (@pxref{Jump Start,,, dmd, GNU dmd
Manual}). For example:
@example
# deco status dmd
@end example
The above command, run as @code{root}, lists the currently defined
services. The @command{deco doc} command shows a synopsis of the given
service:
@example
# deco doc nscd
Run libc's name service cache daemon (nscd).
@end example
The @command{start}, @command{stop}, and @command{restart} sub-commands
have the effect you would expect. For instance, the commands below stop
the nscd service and restart the Xorg display server:
@example
# deco stop nscd
Service nscd has been stopped.
# deco restart xorg-server
Service xorg-server has been stopped.
Service xorg-server has been started.
@end example
The following sections document the available services, starting with
the core services, that may be used in an @code{operating-system}
declaration.
@menu
* Base Services:: Essential system services.
* Networking Services:: Network setup, SSH daemon, etc.
* X Window:: Graphical display.
* Desktop Services:: D-Bus and desktop services.
* Database Services:: SQL databases.
* Mail Services:: IMAP, POP3, SMTP, and all that.
* Web Services:: Web servers.
* Various Services:: Other services.
@end menu
@node Base Services
@subsubsection Base Services
The @code{(gnu services base)} module provides definitions for the basic
services that one expects from the system. The services exported by
this module are listed below.
@defvr {Scheme Variable} %base-services
This variable contains a list of basic services (@pxref{Service Types
and Services}, for more information on service objects) one would
expect from the system: a login service (mingetty) on each tty, syslogd,
libc's name service cache daemon (nscd), the udev device manager, and
more.
This is the default value of the @code{services} field of
@code{operating-system} declarations. Usually, when customizing a
system, you will want to append services to @var{%base-services}, like
this:
@example
(cons* (avahi-service) (lsh-service) %base-services)
@end example
@end defvr
@deffn {Scheme Procedure} host-name-service @var{name}
Return a service that sets the host name to @var{name}.
@end deffn
@deffn {Scheme Procedure} mingetty-service @var{config}
Return a service to run mingetty according to @var{config}, a
@code{<mingetty-configuration>} object, which specifies the tty to run, among
other things.
@end deffn
@deftp {Data Type} mingetty-configuration
This is the data type representing the configuration of Mingetty, which
implements console log-in.
@table @asis
@item @code{tty}
The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
@item @code{motd}
A file-like object containing the ``message of the day''.
@item @code{auto-login} (default: @code{#f})
When true, this field must be a string denoting the user name under
which the system automatically logs in. When it is @code{#f}, a
user name and password must be entered to log in.
@item @code{login-program} (default: @code{#f})
This must be either @code{#f}, in which case the default log-in program
is used (@command{login} from the Shadow tool suite), or a gexp denoting
the name of the log-in program.
@item @code{login-pause?} (default: @code{#f})
When set to @code{#t} in conjunction with @var{auto-login}, the user
will have to press a key before the log-in shell is launched.
@item @code{mingetty} (default: @var{mingetty})
The Mingetty package to use.
@end table
@end deftp
@cindex name service cache daemon
@cindex nscd
@deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
[#:name-services '()]
Return a service that runs libc's name service cache daemon (nscd) with the
given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
Service Switch}, for an example.
@end deffn
@defvr {Scheme Variable} %nscd-default-configuration
This is the default @code{<nscd-configuration>} value (see below) used
by @code{nscd-service}. This uses the caches defined by
@var{%nscd-default-caches}; see below.
@end defvr
@deftp {Data Type} nscd-configuration
This is the type representing the name service cache daemon (nscd)
configuration.
@table @asis
@item @code{name-services} (default: @code{'()})
List of packages denoting @dfn{name services} that must be visible to
the nscd---e.g., @code{(list @var{nss-mdns})}.
@item @code{glibc} (default: @var{glibc})
Package object denoting the GNU C Library providing the @command{nscd}
command.
@item @code{log-file} (default: @code{"/var/log/nscd.log"})
Name of nscd's log file. This is where debugging output goes when
@code{debug-level} is strictly positive.
@item @code{debug-level} (default: @code{0})
Integer denoting the debugging levels. Higher numbers mean more
debugging output is logged.
@item @code{caches} (default: @var{%nscd-default-caches})
List of @code{<nscd-cache>} objects denoting things to be cached; see
below.
@end table
@end deftp
@deftp {Data Type} nscd-cache
Data type representing a cache database of nscd and its parameters.
@table @asis
@item @code{database}
This is a symbol representing the name of the database to be cached.
Valid values are @code{passwd}, @code{group}, @code{hosts}, and
@code{services}, which designate the corresponding NSS database
(@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
@item @code{positive-time-to-live}
@itemx @code{negative-time-to-live} (default: @code{20})
A number representing the number of seconds during which a positive or
negative lookup result remains in cache.
@item @code{check-files?} (default: @code{#t})
Whether to check for updates of the files corresponding to
@var{database}.
For instance, when @var{database} is @code{hosts}, setting this flag
instructs nscd to check for updates in @file{/etc/hosts} and to take
them into account.
@item @code{persistent?} (default: @code{#t})
Whether the cache should be stored persistently on disk.
@item @code{shared?} (default: @code{#t})
Whether the cache should be shared among users.
@item @code{max-database-size} (default: 32@tie{}MiB)
Maximum size in bytes of the database cache.
@c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
@c settings, so leave them out.
@end table
@end deftp
@defvr {Scheme Variable} %nscd-default-caches
List of @code{<nscd-cache>} objects used by default by
@code{nscd-configuration} (see above.)
It enables persistent and aggressive caching of service and host name
lookups. The latter provides better host name lookup performance,
resilience in the face of unreliable name servers, and also better
privacy---often the result of host name lookups is in local cache, so
external name servers do not even need to be queried.
@end defvr
@deffn {Scheme Procedure} syslog-service [#:config-file #f]
Return a service that runs @code{syslogd}. If configuration file name
@var{config-file} is not specified, use some reasonable default
settings.
@end deffn
@anchor{guix-configuration-type}
@deftp {Data Type} guix-configuration
This data type represents the configuration of the Guix build daemon.
@xref{Invoking guix-daemon}, for more information.
@table @asis
@item @code{guix} (default: @var{guix})
The Guix package to use.
@item @code{build-group} (default: @code{"guixbuild"})
Name of the group for build user accounts.
@item @code{build-accounts} (default: @code{10})
Number of build user accounts to create.
@item @code{authorize-key?} (default: @code{#t})
Whether to authorize the substitute key for @code{hydra.gnu.org}
(@pxref{Substitutes}).
@item @code{use-substitutes?} (default: @code{#t})
Whether to use substitutes.
@item @code{substitute-urls} (default: @var{%default-substitute-urls})
The list of URLs where to look for substitutes by default.
@item @code{extra-options} (default: @code{'()})
List of extra command-line options for @command{guix-daemon}.
@item @code{lsof} (default: @var{lsof})
@itemx @code{lsh} (default: @var{lsh})
The lsof and lsh packages to use.
@end table
@end deftp
@deffn {Scheme Procedure} guix-service @var{config}
Return a service that runs the Guix build daemon according to
@var{config}.
@end deffn
@deffn {Scheme Procedure} udev-service [#:udev udev]
Run @var{udev}, which populates the @file{/dev} directory dynamically.
@end deffn
@deffn {Scheme Procedure} console-keymap-service @var{file}
Return a service to load console keymap from @var{file} using
@command{loadkeys} command.
@end deffn
@deffn {Scheme Procedure} gpm-service-type [#:gpm @var{gpm}] @
[#:options]
Run @var{gpm}, the general-purpose mouse daemon, with the given
command-line @var{options}. GPM allows users to use the mouse in the console,
notably to select, copy, and paste text. The default value of @var{options}
uses the @code{ps2} protocol, which works for both USB and PS/2 mice.
This service is not part of @var{%base-services}.
@end deffn
@anchor{guix-publish-service}
@deffn {Scheme Procedure} guix-publish-service [#:guix @var{guix}] @
[#:port 80] [#:host "localhost"]
Return a service that runs @command{guix publish} listening on @var{host}
and @var{port} (@pxref{Invoking guix publish}).
This assumes that @file{/etc/guix} already contains a signing key pair as
created by @command{guix archive --generate-key} (@pxref{Invoking guix
archive}). If that is not the case, the service will fail to start.
@end deffn
@node Networking Services
@subsubsection Networking Services
The @code{(gnu services networking)} module provides services to configure
the network interface.
@cindex DHCP, networking service
@deffn {Scheme Procedure} dhcp-client-service [#:dhcp @var{isc-dhcp}]
Return a service that runs @var{dhcp}, a Dynamic Host Configuration
Protocol (DHCP) client, on all the non-loopback network interfaces.
@end deffn
@deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
[#:gateway #f] [#:name-services @code{'()}]
Return a service that starts @var{interface} with address @var{ip}. If
@var{gateway} is true, it must be a string specifying the default network
gateway.
@end deffn
@cindex wicd
@cindex network management
@deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
management daemon that aims to simplify wired and wireless networking.
This service adds the @var{wicd} package to the global profile, providing
several commands to interact with the daemon and configure networking:
@command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
and @command{wicd-curses} user interfaces.
@end deffn
@cindex NetworkManager
@deffn {Scheme Procedure} network-manager-service @
[#:network-manager @var{network-manager}]
Return a service that runs NetworkManager, a network connection manager
that attempting to keep active network connectivity when available.
@end deffn
@deffn {Scheme Procedure} ntp-service [#:ntp @var{ntp}] @
[#:name-service @var{%ntp-servers}]
Return a service that runs the daemon from @var{ntp}, the
@uref{http://www.ntp.org, Network Time Protocol package}. The daemon will
keep the system clock synchronized with that of @var{servers}.
@end deffn
@defvr {Scheme Variable} %ntp-servers
List of host names used as the default NTP servers.
@end defvr
@deffn {Scheme Procedure} tor-service [@var{config-file}] [#:tor @var{tor}]
Return a service to run the @uref{https://torproject.org, Tor} anonymous
networking daemon.
The daemon runs as the @code{tor} unprivileged user. It is passed
@var{config-file}, a file-like object, with an additional @code{User tor} line
and lines for hidden services added via @code{tor-hidden-service}. Run
@command{man tor} for information about the configuration file.
@end deffn
@deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
Define a new Tor @dfn{hidden service} called @var{name} and implementing
@var{mapping}. @var{mapping} is a list of port/host tuples, such as:
@example
'((22 \"127.0.0.1:22\")
(80 \"127.0.0.1:8080\"))
@end example
In this example, port 22 of the hidden service is mapped to local port 22, and
port 80 is mapped to local port 8080.
This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
the @file{hostname} file contains the @code{.onion} host name for the hidden
service.
See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
project's documentation} for more information.
@end deffn
@deffn {Scheme Procedure} bitlbee-service [#:bitlbee bitlbee] @
[#:interface "127.0.0.1"] [#:port 6667] @
[#:extra-settings ""]
Return a service that runs @url{http://bitlbee.org,BitlBee}, a daemon that
acts as a gateway between IRC and chat networks.
The daemon will listen to the interface corresponding to the IP address
specified in @var{interface}, on @var{port}. @code{127.0.0.1} means that only
local clients can connect, whereas @code{0.0.0.0} means that connections can
come from any networking interface.
In addition, @var{extra-settings} specifies a string to append to the
configuration file.
@end deffn
Furthermore, @code{(gnu services ssh)} provides the following service.
@deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
[#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
[#:allow-empty-passwords? #f] [#:root-login? #f] @
[#:syslog-output? #t] [#:x11-forwarding? #t] @
[#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
[#:public-key-authentication? #t] [#:initialize? #t]
Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
@var{host-key} must designate a file containing the host key, and readable
only by root.
When @var{daemonic?} is true, @command{lshd} will detach from the
controlling terminal and log its output to syslogd, unless one sets
@var{syslog-output?} to false. Obviously, it also makes lsh-service
depend on existence of syslogd service. When @var{pid-file?} is true,
@command{lshd} writes its PID to the file called @var{pid-file}.
When @var{initialize?} is true, automatically create the seed and host key
upon service activation if they do not exist yet. This may take long and
require interaction.
When @var{initialize?} is false, it is up to the user to initialize the
randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
a key pair with the private key stored in file @var{host-key} (@pxref{lshd
basics,,, lsh, LSH Manual}).
When @var{interfaces} is empty, lshd listens for connections on all the
network interfaces; otherwise, @var{interfaces} must be a list of host names
or addresses.
@var{allow-empty-passwords?} specifies whether to accept log-ins with empty
passwords, and @var{root-login?} specifies whether to accept log-ins as
root.
The other options should be self-descriptive.
@end deffn
@defvr {Scheme Variable} %facebook-host-aliases
This variable contains a string for use in @file{/etc/hosts}
(@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
line contains a entry that maps a known server name of the Facebook
on-line service---e.g., @code{www.facebook.com}---to the local
host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
This variable is typically used in the @code{hosts-file} field of an
@code{operating-system} declaration (@pxref{operating-system Reference,
@file{/etc/hosts}}):
@example
(use-modules (gnu) (guix))
(operating-system
(host-name "mymachine")
;; ...
(hosts-file
;; Create a /etc/hosts file with aliases for "localhost"
;; and "mymachine", as well as for Facebook servers.
(plain-file "hosts"
(string-append (local-host-aliases host-name)
%facebook-host-aliases))))
@end example
This mechanism can prevent programs running locally, such as Web
browsers, from accessing Facebook.
@end defvr
The @code{(gnu services avahi)} provides the following definition.
@deffn {Scheme Procedure} avahi-service [#:avahi @var{avahi}] @
[#:host-name #f] [#:publish? #t] [#:ipv4? #t] @
[#:ipv6? #t] [#:wide-area? #f] @
[#:domains-to-browse '()]
Return a service that runs @command{avahi-daemon}, a system-wide
mDNS/DNS-SD responder that allows for service discovery and
"zero-configuration" host name lookups (see @uref{http://avahi.org/}), and
extends the name service cache daemon (nscd) so that it can resolve
@code{.local} host names using
@uref{http://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. Additionally,
add the @var{avahi} package to the system profile so that commands such as
@command{avahi-browse} are directly usable.
If @var{host-name} is different from @code{#f}, use that as the host name to
publish for this machine; otherwise, use the machine's actual host name.
When @var{publish?} is true, publishing of host names and services is allowed;
in particular, avahi-daemon will publish the machine's host name and IP
address via mDNS on the local network.
When @var{wide-area?} is true, DNS-SD over unicast DNS is enabled.
Boolean values @var{ipv4?} and @var{ipv6?} determine whether to use IPv4/IPv6
sockets.
@end deffn
@node X Window
@subsubsection X Window
Support for the X Window graphical display system---specifically
Xorg---is provided by the @code{(gnu services xorg)} module. Note that
there is no @code{xorg-service} procedure. Instead, the X server is
started by the @dfn{login manager}, currently SLiM.
@deffn {Scheme Procedure} slim-service [#:allow-empty-passwords? #f] @
[#:auto-login? #f] [#:default-user ""] [#:startx] @
[#:theme @var{%default-slim-theme}] @
[#:theme-name @var{%default-slim-theme-name}]
Return a service that spawns the SLiM graphical login manager, which in
turn starts the X display server with @var{startx}, a command as returned by
@code{xorg-start-command}.
@cindex X session
SLiM automatically looks for session types described by the @file{.desktop}
files in @file{/run/current-system/profile/share/xsessions} and allows users
to choose a session from the log-in screen using @kbd{F1}. Packages such as
@var{xfce}, @var{sawfish}, and @var{ratpoison} provide @file{.desktop} files;
adding them to the system-wide set of packages automatically makes them
available at the log-in screen.
In addition, @file{~/.xsession} files are honored. When available,
@file{~/.xsession} must be an executable that starts a window manager
and/or other X clients.
When @var{allow-empty-passwords?} is true, allow logins with an empty
password. When @var{auto-login?} is true, log in automatically as
@var{default-user}.
If @var{theme} is @code{#f}, the use the default log-in theme; otherwise
@var{theme} must be a gexp denoting the name of a directory containing the
theme to use. In that case, @var{theme-name} specifies the name of the
theme.
@end deffn
@defvr {Scheme Variable} %default-theme
@defvrx {Scheme Variable} %default-theme-name
The G-Expression denoting the default SLiM theme and its name.
@end defvr
@deffn {Scheme Procedure} xorg-start-command [#:guile] @
[#:configuration-file #f] [#:xorg-server @var{xorg-server}]
Return a derivation that builds a @var{guile} script to start the X server
from @var{xorg-server}. @var{configuration-file} is the server configuration
file or a derivation that builds it; when omitted, the result of
@code{xorg-configuration-file} is used.
Usually the X server is started by a login manager.
@end deffn
@deffn {Scheme Procedure} xorg-configuration-file @
[#:drivers '()] [#:resolutions '()] [#:extra-config '()]
Return a configuration file for the Xorg server containing search paths for
all the common drivers.
@var{drivers} must be either the empty list, in which case Xorg chooses a
graphics driver automatically, or a list of driver names that will be tried in
this order---e.g., @code{(\"modesetting\" \"vesa\")}.
Likewise, when @var{resolutions} is the empty list, Xorg chooses an
appropriate screen resolution; otherwise, it must be a list of
resolutions---e.g., @code{((1024 768) (640 480))}.
Last, @var{extra-config} is a list of strings or objects appended to the
@code{text-file*} argument list. It is used to pass extra text to be added
verbatim to the configuration file.
@end deffn
@deffn {Scheme Procedure} screen-locker-service @var{package} [@var{name}]
Add @var{package}, a package for a screen-locker or screen-saver whose
command is @var{program}, to the set of setuid programs and add a PAM entry
for it. For example:
@lisp
(screen-locker-service xlockmore "xlock")
@end lisp
makes the good ol' XlockMore usable.
@end deffn
@node Desktop Services
@subsubsection Desktop Services
The @code{(gnu services desktop)} module provides services that are
usually useful in the context of a ``desktop'' setup---that is, on a
machine running a graphical display server, possibly with graphical user
interfaces, etc.
To simplify things, the module defines a variable containing the set of
services that users typically expect on a machine with a graphical
environment and networking:
@defvr {Scheme Variable} %desktop-services
This is a list of services that builds upon @var{%base-services} and
adds or adjust services for a typical ``desktop'' setup.
In particular, it adds a graphical login manager (@pxref{X Window,
@code{slim-service}}), screen lockers,
a network management tool (@pxref{Networking
Services, @code{wicd-service}}), energy and color management services,
the @code{elogind} login and seat manager, the Polkit privilege service,
the GeoClue location service, an NTP client (@pxref{Networking
Services}), the Avahi daemon, and has the name service switch service
configured to be able to use @code{nss-mdns} (@pxref{Name Service
Switch, mDNS}).
@end defvr
The @var{%desktop-services} variable can be used as the @code{services}
field of an @code{operating-system} declaration (@pxref{operating-system
Reference, @code{services}}).
The actual service definitions provided by @code{(gnu services dbus)}
and @code{(gnu services desktop)} are described below.
@deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
Return a service that runs the ``system bus'', using @var{dbus}, with
support for @var{services}.
@uref{http://dbus.freedesktop.org/, D-Bus} is an inter-process communication
facility. Its system bus is used to allow system services to communicate
and be notified of system-wide events.
@var{services} must be a list of packages that provide an
@file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
and policy files. For example, to allow avahi-daemon to use the system bus,
@var{services} must be equal to @code{(list avahi)}.
@end deffn
@deffn {Scheme Procedure} elogind-service [#:config @var{config}]
Return a service that runs the @code{elogind} login and
seat management daemon. @uref{https://github.com/andywingo/elogind,
Elogind} exposes a D-Bus interface that can be used to know which users
are logged in, know what kind of sessions they have open, suspend the
system, inhibit system suspend, reboot the system, and other tasks.
Elogind handles most system-level power events for a computer, for
example suspending the system when a lid is closed, or shutting it down
when the power button is pressed.
The @var{config} keyword argument specifies the configuration for
elogind, and should be the result of a @code{(elogind-configuration
(@var{parameter} @var{value})...)} invocation. Available parameters and
their default values are:
@table @code
@item kill-user-processes?
@code{#f}
@item kill-only-users
@code{()}
@item kill-exclude-users
@code{("root")}
@item inhibit-delay-max-seconds
@code{5}
@item handle-power-key
@code{poweroff}
@item handle-suspend-key
@code{suspend}
@item handle-hibernate-key
@code{hibernate}
@item handle-lid-switch
@code{suspend}
@item handle-lid-switch-docked
@code{ignore}
@item power-key-ignore-inhibited?
@code{#f}
@item suspend-key-ignore-inhibited?
@code{#f}
@item hibernate-key-ignore-inhibited?
@code{#f}
@item lid-switch-ignore-inhibited?
@code{#t}
@item holdoff-timeout-seconds
@code{30}
@item idle-action
@code{ignore}
@item idle-action-seconds
@code{(* 30 60)}
@item runtime-directory-size-percent
@code{10}
@item runtime-directory-size
@code{#f}
@item remove-ipc?
@code{#t}
@item suspend-state
@code{("mem" "standby" "freeze")}
@item suspend-mode
@code{()}
@item hibernate-state
@code{("disk")}
@item hibernate-mode
@code{("platform" "shutdown")}
@item hybrid-sleep-state
@code{("disk")}
@item hybrid-sleep-mode
@code{("suspend" "platform" "shutdown")}
@end table
@end deffn
@deffn {Scheme Procedure} polkit-service @
[#:polkit @var{polkit}]
Return a service that runs the
@uref{http://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
management service}, which allows system administrators to grant access to
privileged operations in a structured way. By querying the Polkit service, a
privileged system component can know when it should grant additional
capabilities to ordinary users. For example, an ordinary user can be granted
the capability to suspend the system if the user is logged in locally.
@end deffn
@deffn {Scheme Procedure} upower-service [#:upower @var{upower}] @
[#:watts-up-pro? #f] @
[#:poll-batteries? #t] @
[#:ignore-lid? #f] @
[#:use-percentage-for-policy? #f] @
[#:percentage-low 10] @
[#:percentage-critical 3] @
[#:percentage-action 2] @
[#:time-low 1200] @
[#:time-critical 300] @
[#:time-action 120] @
[#:critical-power-action 'hybrid-sleep]
Return a service that runs @uref{http://upower.freedesktop.org/,
@command{upowerd}}, a system-wide monitor for power consumption and battery
levels, with the given configuration settings. It implements the
@code{org.freedesktop.UPower} D-Bus interface, and is notably used by
GNOME.
@end deffn
@deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
Return a service for @uref{http://udisks.freedesktop.org/docs/latest/,
UDisks}, a @dfn{disk management} daemon that provides user interfaces with
notifications and ways to mount/unmount disks. Programs that talk to UDisks
include the @command{udisksctl} command, part of UDisks, and GNOME Disks.
@end deffn
@deffn {Scheme Procedure} colord-service [#:colord @var{colord}]
Return a service that runs @command{colord}, a system service with a D-Bus
interface to manage the color profiles of input and output devices such as
screens and scanners. It is notably used by the GNOME Color Manager graphical
tool. See @uref{http://www.freedesktop.org/software/colord/, the colord web
site} for more information.
@end deffn
@deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
Return an configuration allowing an application to access GeoClue
location data. @var{name} is the Desktop ID of the application, without
the @code{.desktop} part. If @var{allowed?} is true, the application
will have access to location information by default. The boolean
@var{system?} value indicates that an application is a system component
or not. Finally @var{users} is a list of UIDs of all users for which
this application is allowed location info access. An empty users list
means that all users are allowed.
@end deffn
@defvr {Scheme Variable} %standard-geoclue-applications
The standard list of well-known GeoClue application configurations,
granting authority to GNOME's date-and-time utility to ask for the
current location in order to set the time zone, and allowing the Firefox
(IceCat) and Epiphany web browsers to request location information.
Firefox and Epiphany both query the user before allowing a web page to
know the user's location.
@end defvr
@deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
[#:whitelist '()] @
[#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
[#:submit-data? #f]
[#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
[#:submission-nick "geoclue"] @
[#:applications %standard-geoclue-applications]
Return a service that runs the GeoClue location service. This service
provides a D-Bus interface to allow applications to request access to a
user's physical location, and optionally to add information to online
location databases. See
@uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
web site} for more information.
@end deffn
@node Database Services
@subsubsection Database Services
The @code{(gnu services databases)} module provides the following service.
@deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
[#:config-file] [#:data-directory ``/var/lib/postgresql/data'']
Return a service that runs @var{postgresql}, the PostgreSQL database
server.
The PostgreSQL daemon loads its runtime configuration from
@var{config-file} and stores the database cluster in
@var{data-directory}.
@end deffn
@node Mail Services
@subsubsection Mail Services
The @code{(gnu services mail)} module provides Guix service definitions
for mail services. Currently the only implemented service is Dovecot,
an IMAP, POP3, and LMTP server.
Guix does not yet have a mail transfer agent (MTA), although for some
lightweight purposes the @code{esmtp} relay-only MTA may suffice. Help
is needed to properly integrate a full MTA, such as Postfix. Patches
welcome!
To add an IMAP/POP3 server to a GuixSD system, add a
@code{dovecot-service} to the operating system definition:
@deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
@end deffn
By default, Dovecot doesn't need much configuration; the default
configuration object created by @code{(dovecot-configuration)} will
suffice if your mail is delivered to @code{~/Maildir}. A self-signed
certificate will be generated for TLS-protected connections, though
Dovecot will also listen on cleartext ports by default. There are a
number of options though which mail administrators might need to change,
and as is the case with other services, Guix allows the system
administrator to specify these parameters via a uniform Scheme interface.
For example, to specify that mail is located at @code{maildir~/.mail},
one would instantiate the Dovecot service like this:
@example
(dovecot-service #:config
(dovecot-configuration
(mail-location "maildir:~/.mail")))
@end example
The available configuration parameters follow. Each parameter
definition is preceded by its type; for example, @samp{string-list foo}
indicates that the @code{foo} parameter should be specified as a list of
strings. There is also a way to specify the configuration as a string,
if you have an old @code{dovecot.conf} file that you want to port over
from some other system; see the end for more details.
@c The following documentation was initially generated by
@c (generate-documentation) in (gnu services mail). Manually maintained
@c documentation is better, so we shouldn't hesitate to edit below as
@c needed. However if the change you want to make to this documentation
@c can be done in an automated way, it's probably easier to change
@c (generate-documentation) than to make it below and have to deal with
@c the churn as dovecot updates.
Available @code{dovecot-configuration} fields are:
@deftypevr {@code{dovecot-configuration} parameter} package dovecot
The dovecot package.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
A list of IPs or hosts where to listen in for connections. @samp{*}
listens in all IPv4 interfaces, @samp{::} listens in all IPv6
interfaces. If you want to specify non-default ports or anything more
complex, customize the address and port fields of the
@samp{inet-listener} of the specific services you are interested in.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
List of protocols we want to serve. Available protocols include
@samp{imap}, @samp{pop3}, and @samp{lmtp}.
Available @code{protocol-configuration} fields are:
@deftypevr {@code{protocol-configuration} parameter} string name
The name of the protocol.
@end deftypevr
@deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
UNIX socket path to master authentication server to find users.
This is used by imap (for shared users) and lda.
Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
@end deftypevr
@deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
Space separated list of plugins to load.
@end deftypevr
@deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
Maximum number of IMAP connections allowed for a user from each IP
address. NOTE: The username is compared case-sensitively.
Defaults to @samp{10}.
@end deftypevr
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
List of services to enable. Available services include @samp{imap},
@samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
@samp{lmtp}.
Available @code{service-configuration} fields are:
@deftypevr {@code{service-configuration} parameter} string kind
The service kind. Valid values include @code{director},
@code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
@code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
@code{tcpwrap}, @code{quota-warning}, or anything else.
@end deftypevr
@deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
Listeners for the service. A listener is either an
@code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
an @code{inet-listener-configuration}.
Defaults to @samp{()}.
Available @code{unix-listener-configuration} fields are:
@deftypevr {@code{unix-listener-configuration} parameter} file-name path
The file name on which to listen.
@end deftypevr
@deftypevr {@code{unix-listener-configuration} parameter} string mode
The access mode for the socket.
Defaults to @samp{"0600"}.
@end deftypevr
@deftypevr {@code{unix-listener-configuration} parameter} string user
The user to own the socket.
Defaults to @samp{""}.
@end deftypevr
@deftypevr {@code{unix-listener-configuration} parameter} string group
The group to own the socket.
Defaults to @samp{""}.
@end deftypevr
Available @code{fifo-listener-configuration} fields are:
@deftypevr {@code{fifo-listener-configuration} parameter} file-name path
The file name on which to listen.
@end deftypevr
@deftypevr {@code{fifo-listener-configuration} parameter} string mode
The access mode for the socket.
Defaults to @samp{"0600"}.
@end deftypevr
@deftypevr {@code{fifo-listener-configuration} parameter} string user
The user to own the socket.
Defaults to @samp{""}.
@end deftypevr
@deftypevr {@code{fifo-listener-configuration} parameter} string group
The group to own the socket.
Defaults to @samp{""}.
@end deftypevr
Available @code{inet-listener-configuration} fields are:
@deftypevr {@code{inet-listener-configuration} parameter} string protocol
The protocol to listen for.
@end deftypevr
@deftypevr {@code{inet-listener-configuration} parameter} string address
The address on which to listen, or empty for all addresses.
Defaults to @samp{""}.
@end deftypevr
@deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
The port on which to listen.
@end deftypevr
@deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
Whether to use SSL for this service; @samp{yes}, @samp{no}, or
@samp{required}.
Defaults to @samp{#t}.
@end deftypevr
@end deftypevr
@deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
Number of connections to handle before starting a new process.
Typically the only useful values are 0 (unlimited) or 1. 1 is more
secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
Defaults to @samp{1}.
@end deftypevr
@deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
Number of processes to always keep waiting for more connections.
Defaults to @samp{0}.
@end deftypevr
@deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
If you set @samp{service-count 0}, you probably need to grow
this.
Defaults to @samp{256000000}.
@end deftypevr
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
Dict configuration, as created by the @code{dict-configuration}
constructor.
Available @code{dict-configuration} fields are:
@deftypevr {@code{dict-configuration} parameter} free-form-fields entries
A list of key-value pairs that this dict should hold.
Defaults to @samp{()}.
@end deftypevr
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
List of passdb configurations, each one created by the
@code{passdb-configuration} constructor.
Available @code{passdb-configuration} fields are:
@deftypevr {@code{passdb-configuration} parameter} string driver
The driver that the passdb should use. Valid values include
@samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
@samp{static}.
Defaults to @samp{"pam"}.
@end deftypevr
@deftypevr {@code{passdb-configuration} parameter} free-form-args args
A list of key-value args to the passdb driver.
Defaults to @samp{()}.
@end deftypevr
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
List of userdb configurations, each one created by the
@code{userdb-configuration} constructor.
Available @code{userdb-configuration} fields are:
@deftypevr {@code{userdb-configuration} parameter} string driver
The driver that the userdb should use. Valid values include
@samp{passwd} and @samp{static}.
Defaults to @samp{"passwd"}.
@end deftypevr
@deftypevr {@code{userdb-configuration} parameter} free-form-args args
A list of key-value args to the userdb driver.
Defaults to @samp{()}.
@end deftypevr
@deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
Override fields from passwd.
Defaults to @samp{()}.
@end deftypevr
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
Plug-in configuration, created by the @code{plugin-configuration}
constructor.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
List of namespaces. Each item in the list is created by the
@code{namespace-configuration} constructor.
Available @code{namespace-configuration} fields are:
@deftypevr {@code{namespace-configuration} parameter} string name
Name for this namespace.
@end deftypevr
@deftypevr {@code{namespace-configuration} parameter} string type
Namespace type: @samp{private}, @samp{shared} or @samp{public}.
Defaults to @samp{"private"}.
@end deftypevr
@deftypevr {@code{namespace-configuration} parameter} string separator
Hierarchy separator to use. You should use the same separator for
all namespaces or some clients get confused. @samp{/} is usually a good
one. The default however depends on the underlying mail storage
format.
Defaults to @samp{""}.
@end deftypevr
@deftypevr {@code{namespace-configuration} parameter} string prefix
Prefix required to access this namespace. This needs to be
different for all namespaces. For example @samp{Public/}.
Defaults to @samp{""}.
@end deftypevr
@deftypevr {@code{namespace-configuration} parameter} string location
Physical location of the mailbox. This is in same format as
mail_location, which is also the default for it.
Defaults to @samp{""}.
@end deftypevr
@deftypevr {@code{namespace-configuration} parameter} boolean inbox?
There can be only one INBOX, and this setting defines which
namespace has it.
Defaults to @samp{#f}.
@end deftypevr
@deftypevr {@code{namespace-configuration} parameter} boolean hidden?
If namespace is hidden, it's not advertised to clients via NAMESPACE
extension. You'll most likely also want to set @samp{list? #f}. This is mostly
useful when converting from another server with different namespaces
which you want to deprecate but still keep working. For example you can
create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
and @samp{mail/}.
Defaults to @samp{#f}.
@end deftypevr
@deftypevr {@code{namespace-configuration} parameter} boolean list?
Show the mailboxes under this namespace with LIST command. This
makes the namespace visible for clients that don't support NAMESPACE
extension. The special @code{children} value lists child mailboxes, but
hides the namespace prefix.
Defaults to @samp{#t}.
@end deftypevr
@deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
Namespace handles its own subscriptions. If set to @code{#f}, the
parent namespace handles them. The empty prefix should always have this
as @code{#t}.)
Defaults to @samp{#t}.
@end deftypevr
@deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
List of predefined mailboxes in this namespace.
Defaults to @samp{()}.
Available @code{mailbox-configuration} fields are:
@deftypevr {@code{mailbox-configuration} parameter} string name
Name for this mailbox.
@end deftypevr
@deftypevr {@code{mailbox-configuration} parameter} string auto
@samp{create} will automatically create this mailbox.
@samp{subscribe} will both create and subscribe to the mailbox.
Defaults to @samp{"no"}.
@end deftypevr
@deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
@code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
Defaults to @samp{()}.
@end deftypevr
@end deftypevr
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
Base directory where to store runtime data.
Defaults to @samp{"/var/run/dovecot/"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string login-greeting
Greeting message for clients.
Defaults to @samp{"Dovecot ready."}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
List of trusted network ranges. Connections from these IPs are
allowed to override their IP addresses and ports (for logging and for
authentication checks). @samp{disable-plaintext-auth} is also ignored
for these networks. Typically you'd specify your IMAP proxy servers
here.
Defaults to @samp{()}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
List of login access check sockets (e.g. tcpwrap).
Defaults to @samp{()}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
Show more verbose process titles (in ps). Currently shows user name
and IP address. Useful for seeing who are actually using the IMAP
processes (e.g. shared mailboxes or if same uid is used for multiple
accounts).
Defaults to @samp{#f}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
Should all processes be killed when Dovecot master process shuts down.
Setting this to @code{#f} means that Dovecot can be upgraded without
forcing existing client connections to close (although that could also
be a problem if the upgrade is e.g. because of a security fix).
Defaults to @samp{#t}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
If non-zero, run mail commands via this many connections to doveadm
server, instead of running them directly in the same process.
Defaults to @samp{0}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
UNIX socket or host:port used for connecting to doveadm server.
Defaults to @samp{"doveadm-server"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
List of environment variables that are preserved on Dovecot startup
and passed down to all of its child processes. You can also give
key=value pairs to always set specific settings.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
Disable LOGIN command and all other plaintext authentications unless
SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
matches the local IP (i.e. you're connecting from the same computer),
the connection is considered secure and plaintext authentication is
allowed. See also ssl=required setting.
Defaults to @samp{#t}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
Authentication cache size (e.g. @samp{#e10e6}). 0 means it's disabled.
Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
for caching to be used.
Defaults to @samp{0}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
Time to live for cached data. After TTL expires the cached record
is no longer used, *except* if the main database lookup returns internal
failure. We also try to handle password changes automatically: If
user's previous authentication was successful, but this one wasn't, the
cache isn't used. For now this works only with plaintext
authentication.
Defaults to @samp{"1 hour"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
TTL for negative hits (user not found, password mismatch).
0 disables caching them completely.
Defaults to @samp{"1 hour"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
List of realms for SASL authentication mechanisms that need them.
You can leave it empty if you don't want to support multiple realms.
Many clients simply use the first one listed here, so keep the default
realm first.
Defaults to @samp{()}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
Default realm/domain to use if none was specified. This is used for
both SASL realms and appending @@domain to username in plaintext
logins.
Defaults to @samp{""}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
List of allowed characters in username. If the user-given username
contains a character not listed in here, the login automatically fails.
This is just an extra check to make sure user can't exploit any
potential quote escaping vulnerabilities with SQL/LDAP databases. If
you want to allow all characters, set this value to empty.
Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
Username character translations before it's looked up from
databases. The value contains series of from -> to characters. For
example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
translated to @samp{@@}.
Defaults to @samp{""}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
Username formatting before it's looked up from databases. You can
use the standard variables here, e.g. %Lu would lowercase the username,
%n would drop away the domain if it was given, or @samp{%n-AT-%d} would
change the @samp{@@} into @samp{-AT-}. This translation is done after
@samp{auth-username-translation} changes.
Defaults to @samp{"%Lu"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
If you want to allow master users to log in by specifying the master
username within the normal username string (i.e. not using SASL
mechanism's support for it), you can specify the separator character
here. The format is then <username><separator><master username>.
UW-IMAP uses @samp{*} as the separator, so that could be a good
choice.
Defaults to @samp{""}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
Username to use for users logging in with ANONYMOUS SASL
mechanism.
Defaults to @samp{"anonymous"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
Maximum number of dovecot-auth worker processes. They're used to
execute blocking passdb and userdb queries (e.g. MySQL and PAM).
They're automatically created and destroyed as needed.
Defaults to @samp{30}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
Host name to use in GSSAPI principal names. The default is to use
the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
allow all keytab entries.
Defaults to @samp{""}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
Kerberos keytab to use for the GSSAPI mechanism. Will use the
system default (usually /etc/krb5.keytab) if not specified. You may
need to change the auth service to run as root to be able to read this
file.
Defaults to @samp{""}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
and @samp{ntlm-auth} helper.
<doc/wiki/Authentication/Mechanisms/Winbind.txt>.
Defaults to @samp{#f}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
Path for Samba's @samp{ntlm-auth} helper binary.
Defaults to @samp{"/usr/bin/ntlm_auth"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
Time to delay before replying to failed authentications.
Defaults to @samp{"2 secs"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
Require a valid SSL client certificate or the authentication
fails.
Defaults to @samp{#f}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
Take the username from client's SSL certificate, using
@code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
CommonName.
Defaults to @samp{#f}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
List of wanted authentication mechanisms. Supported mechanisms are:
@samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
@samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
@samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
@samp{disable-plaintext-auth} setting.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
List of IPs or hostnames to all director servers, including ourself.
Ports can be specified as ip:port. The default port is the same as what
director service's @samp{inet-listener} is using.
Defaults to @samp{()}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
List of IPs or hostnames to all backend mail servers. Ranges are
allowed too, like 10.0.0.10-10.0.0.30.
Defaults to @samp{()}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
How long to redirect users to a specific server after it no longer
has any connections.
Defaults to @samp{"15 min"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} non-negative-integer director-doveadm-port
TCP/IP port that accepts doveadm connections (instead of director
connections) If you enable this, you'll also need to add
@samp{inet-listener} for the port.
Defaults to @samp{0}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
How the username is translated before being hashed. Useful values
include %Ln if user can log in with or without @@domain, %Ld if mailboxes
are shared within domain.
Defaults to @samp{"%Lu"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string log-path
Log file to use for error messages. @samp{syslog} logs to syslog,
@samp{/dev/stderr} logs to stderr.
Defaults to @samp{"syslog"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string info-log-path
Log file to use for informational messages. Defaults to
@samp{log-path}.
Defaults to @samp{""}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
Log file to use for debug messages. Defaults to
@samp{info-log-path}.
Defaults to @samp{""}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
Syslog facility to use if you're logging to syslog. Usually if you
don't want to use @samp{mail}, you'll use local0..local7. Also other
standard facilities are supported.
Defaults to @samp{"mail"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
Log unsuccessful authentication attempts and the reasons why they
failed.
Defaults to @samp{#f}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose-passwords?
In case of password mismatches, log the attempted password. Valid
values are no, plain and sha1. sha1 can be useful for detecting brute
force password attempts vs. user simply trying the same password over
and over again. You can also truncate the value to n chars by appending
":n" (e.g. sha1:6).
Defaults to @samp{#f}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
Even more verbose logging for debugging purposes. Shows for example
SQL queries.
Defaults to @samp{#f}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
In case of password mismatches, log the passwords and used scheme so
the problem can be debugged. Enabling this also enables
@samp{auth-debug}.
Defaults to @samp{#f}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
Enable mail process debugging. This can help you figure out why
Dovecot isn't finding your mails.
Defaults to @samp{#f}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
Show protocol level SSL errors.
Defaults to @samp{#f}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
Prefix for each line written to log file. % codes are in
strftime(3) format.
Defaults to @samp{"\"%b %d %H:%M:%S \""}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
List of elements we want to log. The elements which have a
non-empty variable value are joined together to form a comma-separated
string.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string login-log-format
Login log format. %s contains @samp{login-log-format-elements}
string, %$ contains the data we want to log.
Defaults to @samp{"%$: %s"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
Log prefix for mail processes. See doc/wiki/Variables.txt for list
of possible variables you can use.
Defaults to @samp{"\"%s(%u): \""}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
Format to use for logging mail deliveries. You can use variables:
@table @code
@item %$
Delivery status message (e.g. @samp{saved to INBOX})
@item %m
Message-ID
@item %s
Subject
@item %f
From address
@item %p
Physical size
@item %w
Virtual size.
@end table
Defaults to @samp{"msgid=%m: %$"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string mail-location
Location for users' mailboxes. The default is empty, which means
that Dovecot tries to find the mailboxes automatically. This won't work
if the user doesn't yet have any mail, so you should explicitly tell
Dovecot the full location.
If you're using mbox, giving a path to the INBOX
file (e.g. /var/mail/%u) isn't enough. You'll also need to tell Dovecot
where the other mailboxes are kept. This is called the "root mail
directory", and it must be the first path given in the
@samp{mail-location} setting.
There are a few special variables you can use, eg.:
@table @samp
@item %u
username
@item %n
user part in user@@domain, same as %u if there's no domain
@item %d
domain part in user@@domain, empty if there's no domain
@item %h
home director
@end table
See doc/wiki/Variables.txt for full list. Some examples:
@table @samp
@item maildir:~/Maildir
@item mbox:~/mail:INBOX=/var/mail/%u
@item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
@end table
Defaults to @samp{""}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string mail-uid
System user and group used to access mails. If you use multiple,
userdb can override these by returning uid or gid fields. You can use
either numbers or names. <doc/wiki/UserIds.txt>.
Defaults to @samp{""}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string mail-gid
Defaults to @samp{""}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
Group to enable temporarily for privileged operations. Currently
this is used only with INBOX when either its initial creation or
dotlocking fails. Typically this is set to "mail" to give access to
/var/mail.
Defaults to @samp{""}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
Grant access to these supplementary groups for mail processes.
Typically these are used to set up access to shared mailboxes. Note
that it may be dangerous to set these if users can create
symlinks (e.g. if "mail" group is set here, ln -s /var/mail ~/mail/var
could allow a user to delete others' mailboxes, or ln -s
/secret/shared/box ~/mail/mybox would allow reading it).
Defaults to @samp{""}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
Allow full filesystem access to clients. There's no access checks
other than what the operating system does for the active UID/GID. It
works with both maildir and mboxes, allowing you to prefix mailboxes
names with e.g. /path/ or ~user/.
Defaults to @samp{#f}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
Don't use mmap() at all. This is required if you store indexes to
shared filesystems (NFS or clustered filesystem).
Defaults to @samp{#f}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
supports @samp{O_EXCL} since version 3, so this should be safe to use
nowadays by default.
Defaults to @samp{#t}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
When to use fsync() or fdatasync() calls:
@table @code
@item optimized
Whenever necessary to avoid losing important data
@item always
Useful with e.g. NFS when write()s are delayed
@item never
Never use it (best performance, but crashes can lose data).
@end table
Defaults to @samp{"optimized"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
Mail storage exists in NFS. Set this to yes to make Dovecot flush
NFS caches whenever needed. If you're using only a single mail server
this isn't needed.
Defaults to @samp{#f}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
Mail index files also exist in NFS. Setting this to yes requires
@samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
Defaults to @samp{#f}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string lock-method
Locking method for index files. Alternatives are fcntl, flock and
dotlock. Dotlocking uses some tricks which may create more disk I/O
than other locking methods. NFS users: flock doesn't work, remember to
change @samp{mmap-disable}.
Defaults to @samp{"fcntl"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
Directory in which LDA/LMTP temporarily stores incoming mails >128
kB.
Defaults to @samp{"/tmp"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
Valid UID range for users. This is mostly to make sure that users can't
log in as daemons or other system users. Note that denying root logins is
hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
is set to 0.
Defaults to @samp{500}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
Defaults to @samp{0}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
Valid GID range for users. Users having non-valid GID as primary group ID
aren't allowed to log in. If user belongs to supplementary groups with
non-valid GIDs, those groups are not set.
Defaults to @samp{1}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
Defaults to @samp{0}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
Maximum allowed length for mail keyword name. It's only forced when
trying to create new keywords.
Defaults to @samp{50}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
List of directories under which chrooting is allowed for mail
processes (i.e. /var/mail will allow chrooting to /var/mail/foo/bar
too). This setting doesn't affect @samp{login-chroot}
@samp{mail-chroot} or auth chroot settings. If this setting is empty,
"/./" in home dirs are ignored. WARNING: Never add directories here
which local users can modify, that may lead to root exploit. Usually
this should be done only if you don't allow shell access for users.
<doc/wiki/Chrooting.txt>.
Defaults to @samp{()}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
Default chroot directory for mail processes. This can be overridden
for specific users in user database by giving /./ in user's home
directory (e.g. /home/./user chroots into /home). Note that usually
there is no real need to do chrooting, Dovecot doesn't allow users to
access files outside their mail directory anyway. If your home
directories are prefixed with the chroot directory, append "/." to
@samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
Defaults to @samp{""}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
UNIX socket path to master authentication server to find users.
This is used by imap (for shared users) and lda.
Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
Directory where to look up mail plugins.
Defaults to @samp{"/usr/lib/dovecot"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
List of plugins to load for all services. Plugins specific to IMAP,
LDA, etc. are added to this list in their own .conf files.
Defaults to @samp{()}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
The minimum number of mails in a mailbox before updates are done to
cache file. This allows optimizing Dovecot's behavior to do less disk
writes at the cost of more disk reads.
Defaults to @samp{0}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
When IDLE command is running, mailbox is checked once in a while to
see if there are any new mails or other changes. This setting defines
the minimum time to wait between those checks. Dovecot can also use
dnotify, inotify and kqueue to find out immediately when changes
occur.
Defaults to @samp{"30 secs"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
Save mails with CR+LF instead of plain LF. This makes sending those
mails take less CPU, especially with sendfile() syscall with Linux and
FreeBSD. But it also creates a bit more disk I/O which may just make it
slower. Also note that if other software reads the mboxes/maildirs,
they may handle the extra CRs wrong and cause problems.
Defaults to @samp{#f}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
By default LIST command returns all entries in maildir beginning
with a dot. Enabling this option makes Dovecot return only entries
which are directories. This is done by stat()ing each entry, so it
causes more disk I/O.
(For systems setting struct @samp{dirent->d_type} this check is free
and it's done always regardless of this setting).
Defaults to @samp{#f}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
When copying a message, do it with hard links whenever possible.
This makes the performance much better, and it's unlikely to have any
side effects.
Defaults to @samp{#t}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
Assume Dovecot is the only MUA accessing Maildir: Scan cur/
directory only when its mtime changes unexpectedly or when we can't find
the mail otherwise.
Defaults to @samp{#f}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
Which locking methods to use for locking mbox. There are four
available:
@table @code
@item dotlock
Create <mailbox>.lock file. This is the oldest and most NFS-safe
solution. If you want to use /var/mail/ like directory, the users will
need write access to that directory.
@item dotlock-try
Same as dotlock, but if it fails because of permissions or because there
isn't enough disk space, just skip it.
@item fcntl
Use this if possible. Works with NFS too if lockd is used.
@item flock
May not exist in all systems. Doesn't work with NFS.
@item lockf
May not exist in all systems. Doesn't work with NFS.
@end table
You can use multiple locking methods; if you do the order they're declared
in is important to avoid deadlocks if other MTAs/MUAs are using multiple
locking methods as well. Some operating systems don't allow using some of
them simultaneously.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
Maximum time to wait for lock (all of them) before aborting.
Defaults to @samp{"5 mins"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
If dotlock exists but the mailbox isn't modified in any way,
override the lock file after this much time.
Defaults to @samp{"2 mins"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
When mbox changes unexpectedly we have to fully read it to find out
what changed. If the mbox is large this can take a long time. Since
the change is usually just a newly appended mail, it'd be faster to
simply read the new mails. If this setting is enabled, Dovecot does
this but still safely fallbacks to re-reading the whole mbox file
whenever something in mbox isn't how it's expected to be. The only real
downside to this setting is that if some other MUA changes message
flags, Dovecot doesn't notice it immediately. Note that a full sync is
done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
Defaults to @samp{#t}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
EXAMINE, EXPUNGE or CHECK commands. If this is set,
@samp{mbox-dirty-syncs} is ignored.
Defaults to @samp{#f}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
Delay writing mbox headers until doing a full write sync (EXPUNGE
and CHECK commands and when closing the mailbox). This is especially
useful for POP3 where clients often delete all mails. The downside is
that our changes aren't immediately visible to other MUAs.
Defaults to @samp{#t}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
If mbox size is smaller than this (e.g. 100k), don't write index
files. If an index file already exists it's still read, just not
updated.
Defaults to @samp{0}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
Maximum dbox file size until it's rotated.
Defaults to @samp{2000000}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
Maximum dbox file age until it's rotated. Typically in days. Day
begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
disabled.
Defaults to @samp{"1d"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
When creating new mdbox files, immediately preallocate their size to
@samp{mdbox-rotate-size}. This setting currently works only in Linux
with some filesystems (ext4, xfs).
Defaults to @samp{#f}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
sdbox and mdbox support saving mail attachments to external files,
which also allows single instance storage for them. Other backends
don't support this for now.
WARNING: This feature hasn't been tested much yet. Use at your own risk.
Directory root where to store mail attachments. Disabled, if empty.
Defaults to @samp{""}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
Attachments smaller than this aren't saved externally. It's also
possible to write a plugin to disable saving specific attachments
externally.
Defaults to @samp{128000}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
Filesystem backend to use for saving attachments:
@table @code
@item posix
No SiS done by Dovecot (but this might help FS's own deduplication)
@item sis posix
SiS with immediate byte-by-byte comparison during saving
@item sis-queue posix
SiS with delayed comparison and deduplication.
@end table
Defaults to @samp{"sis posix"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
Hash format to use in attachment filenames. You can add any text and
variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
@code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
truncated, e.g. @code{%@{sha256:80@}} returns only first 80 bits.
Defaults to @samp{"%@{sha1@}"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
Defaults to @samp{100}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
Defaults to @samp{1000}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
Default VSZ (virtual memory size) limit for service processes.
This is mainly intended to catch and kill processes that leak memory
before they eat up everything.
Defaults to @samp{256000000}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string default-login-user
Login user is internally used by login processes. This is the most
untrusted user in Dovecot system. It shouldn't have access to anything
at all.
Defaults to @samp{"dovenull"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
Internal user is used by unprivileged processes. It should be
separate from login user, so that login processes can't disturb other
processes.
Defaults to @samp{"dovecot"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string ssl?
SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
Defaults to @samp{"required"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
PEM encoded X.509 SSL/TLS certificate (public key).
Defaults to @samp{"</etc/dovecot/default.pem"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string ssl-key
PEM encoded SSL/TLS private key. The key is opened before
dropping root privileges, so keep the key file unreadable by anyone but
root.
Defaults to @samp{"</etc/dovecot/private/default.pem"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
If key file is password protected, give the password here.
Alternatively give it when starting dovecot with -p parameter. Since
this file is often world-readable, you may want to place this setting
instead to a different.
Defaults to @samp{""}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
PEM encoded trusted certificate authority. Set this only if you
intend to use @samp{ssl-verify-client-cert? #t}. The file should
contain the CA certificate(s) followed by the matching
CRL(s). (e.g. @samp{ssl-ca </etc/ssl/certs/ca.pem}).
Defaults to @samp{""}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
Require that CRL check succeeds for client certificates.
Defaults to @samp{#t}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
Request client to send a certificate. If you also want to require
it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
Defaults to @samp{#f}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
Which field from certificate to use for username. commonName and
x500UniqueIdentifier are the usual choices. You'll also need to set
@samp{auth-ssl-username-from-cert? #t}.
Defaults to @samp{"commonName"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} hours ssl-parameters-regenerate
How often to regenerate the SSL parameters file. Generation is
quite CPU intensive operation. The value is in hours, 0 disables
regeneration entirely.
Defaults to @samp{168}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string ssl-protocols
SSL protocols to use.
Defaults to @samp{"!SSLv2"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
SSL ciphers to use.
Defaults to @samp{"ALL:!LOW:!SSLv2:!EXP:!aNULL"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
SSL crypto device to use, for valid values run "openssl engine".
Defaults to @samp{""}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
Address to use when sending rejection mails.
Default is postmaster@@<your domain>. %d expands to recipient domain.
Defaults to @samp{""}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string hostname
Hostname to use in various parts of sent mails (e.g. in Message-Id)
and in LMTP replies. Default is the system's real hostname@@domain.
Defaults to @samp{""}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
If user is over quota, return with temporary failure instead of
bouncing the mail.
Defaults to @samp{#f}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
Binary to use for sending mails.
Defaults to @samp{"/usr/sbin/sendmail"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string submission-host
If non-empty, send mails via this SMTP host[:port] instead of
sendmail.
Defaults to @samp{""}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
Subject: header to use for rejection mails. You can use the same
variables as for @samp{rejection-reason} below.
Defaults to @samp{"Rejected: %s"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
Human readable error message for rejection mails. You can use
variables:
@table @code
@item %n
CRLF
@item %r
reason
@item %s
original subject
@item %t
recipient
@end table
Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
Delimiter character between local-part and detail in email
address.
Defaults to @samp{"+"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
Header where the original recipient address (SMTP's RCPT TO:
address) is taken from if not available elsewhere. With dovecot-lda -a
parameter overrides this. A commonly used header for this is
X-Original-To.
Defaults to @samp{""}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
Should saving a mail to a nonexistent mailbox automatically create
it?.
Defaults to @samp{#f}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
Should automatically created mailboxes be also automatically
subscribed?.
Defaults to @samp{#f}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
Maximum IMAP command line length. Some clients generate very long
command lines with huge mailboxes, so you may need to raise this if you
get "Too long argument" or "IMAP command line too large" errors
often.
Defaults to @samp{64000}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
IMAP logout format string:
@table @code
@item %i
total number of bytes read from client
@item %o
total number of bytes sent to client.
@end table
Defaults to @samp{"in=%i out=%o"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string imap-capability
Override the IMAP CAPABILITY response. If the value begins with '+',
add the given capabilities on top of the defaults (e.g. +XFOO XBAR).
Defaults to @samp{""}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
How long to wait between "OK Still here" notifications when client
is IDLEing.
Defaults to @samp{"2 mins"}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
ID field names and values to send to clients. Using * as the value
makes Dovecot use the default value. The following fields have default
values currently: name, version, os, os-version, support-url,
support-email.
Defaults to @samp{""}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
ID fields sent by client to log. * means everything.
Defaults to @samp{""}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
Workarounds for various client bugs:
@table @code
@item delay-newmail
Send EXISTS/RECENT new mail notifications only when replying to NOOP and
CHECK commands. Some clients ignore them otherwise, for example OSX
Mail (<v2.1). Outlook Express breaks more badly though, without this it
may show user "Message no longer in server" errors. Note that OE6
still breaks even with this workaround if synchronization is set to
"Headers Only".
@item tb-extra-mailbox-sep
Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
ignore the extra @samp{/} instead of treating it as invalid mailbox name.
@item tb-lsub-flags
Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g. mbox).
This makes Thunderbird realize they aren't selectable and show them
greyed out, instead of only later giving "not selectable" popup error.
@end table
Defaults to @samp{()}.
@end deftypevr
@deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
Host allowed in URLAUTH URLs sent by client. "*" allows all.
Defaults to @samp{""}.
@end deftypevr
Whew! Lots of configuration options. The nice thing about it though is
that GuixSD has a complete interface to Dovecot's configuration
language. This allows not only a nice way to declare configurations,
but also offers reflective capabilities as well: users can write code to
inspect and transform configurations from within Scheme.
However, it could be that you just want to get a @code{dovecot.conf} up
and running. In that case, you can pass an
@code{opaque-dovecot-configuration} as the @code{#:config} paramter to
@code{dovecot-service}. As its name indicates, an opaque configuration
does not have easy reflective capabilities.
Available @code{opaque-dovecot-configuration} fields are:
@deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
The dovecot package.
@end deftypevr
@deftypevr {@code{opaque-dovecot-configuration} parameter} string string
The contents of the @code{dovecot.conf}, as a string.
@end deftypevr
For example, if your @code{dovecot.conf} is just the empty string, you
could instantiate a dovecot service like this:
@example
(dovecot-service #:config
(opaque-dovecot-configuration
(string "")))
@end example
@node Web Services
@subsubsection Web Services
The @code{(gnu services web)} module provides the following service:
@deffn {Scheme Procedure} nginx-service [#:nginx nginx] @
[#:log-directory ``/var/log/nginx''] @
[#:run-directory ``/var/run/nginx''] @
[#:config-file]
Return a service that runs @var{nginx}, the nginx web server.
The nginx daemon loads its runtime configuration from @var{config-file}.
Log files are written to @var{log-directory} and temporary runtime data
files are written to @var{run-directory}. For proper operation, these
arguments should match what is in @var{config-file} to ensure that the
directories are created when the service is activated.
@end deffn
@node Various Services
@subsubsection Various Services
The @code{(gnu services lirc)} module provides the following service.
@deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
[#:device #f] [#:driver #f] [#:config-file #f] @
[#:extra-options '()]
Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
decodes infrared signals from remote controls.
Optionally, @var{device}, @var{driver} and @var{config-file}
(configuration file name) may be specified. See @command{lircd} manual
for details.
Finally, @var{extra-options} is a list of additional command-line options
passed to @command{lircd}.
@end deffn
@node Setuid Programs
@subsection Setuid Programs
@cindex setuid programs
Some programs need to run with ``root'' privileges, even when they are
launched by unprivileged users. A notorious example is the
@command{passwd} program, which users can run to change their
password, and which needs to access the @file{/etc/passwd} and
@file{/etc/shadow} files---something normally restricted to root, for
obvious security reasons. To address that, these executables are
@dfn{setuid-root}, meaning that they always run with root privileges
(@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
for more info about the setuid mechanism.)
The store itself @emph{cannot} contain setuid programs: that would be a
security issue since any user on the system can write derivations that
populate the store (@pxref{The Store}). Thus, a different mechanism is
used: instead of changing the setuid bit directly on files that are in
the store, we let the system administrator @emph{declare} which programs
should be setuid root.
The @code{setuid-programs} field of an @code{operating-system}
declaration contains a list of G-expressions denoting the names of
programs to be setuid-root (@pxref{Using the Configuration System}).
For instance, the @command{passwd} program, which is part of the Shadow
package, can be designated by this G-expression (@pxref{G-Expressions}):
@example
#~(string-append #$shadow "/bin/passwd")
@end example
A default set of setuid programs is defined by the
@code{%setuid-programs} variable of the @code{(gnu system)} module.
@defvr {Scheme Variable} %setuid-programs
A list of G-expressions denoting common programs that are setuid-root.
The list includes commands such as @command{passwd}, @command{ping},
@command{su}, and @command{sudo}.
@end defvr
Under the hood, the actual setuid programs are created in the
@file{/run/setuid-programs} directory at system activation time. The
files in this directory refer to the ``real'' binaries, which are in the
store.
@node X.509 Certificates
@subsection X.509 Certificates
@cindex HTTPS, certificates
@cindex X.509 certificates
@cindex TLS
Web servers available over HTTPS (that is, HTTP over the transport-layer
security mechanism, TLS) send client programs an @dfn{X.509 certificate}
that the client can then use to @emph{authenticate} the server. To do
that, clients verify that the server's certificate is signed by a
so-called @dfn{certificate authority} (CA). But to verify the CA's
signature, clients must have first acquired the CA's certificate.
Web browsers such as GNU@tie{}IceCat include their own set of CA
certificates, such that they are able to verify CA signatures
out-of-the-box.
However, most other programs that can talk HTTPS---@command{wget},
@command{git}, @command{w3m}, etc.---need to be told where CA
certificates can be found.
@cindex @code{nss-certs}
In GuixSD, this is done by adding a package that provides certificates
to the @code{packages} field of the @code{operating-system} declaration
(@pxref{operating-system Reference}). GuixSD includes one such package,
@code{nss-certs}, which is a set of CA certificates provided as part of
Mozilla's Network Security Services.
Note that it is @emph{not} part of @var{%base-packages}, so you need to
explicitly add it. The @file{/etc/ssl/certs} directory, which is where
most applications and libraries look for certificates by default, points
to the certificates installed globally.
Unprivileged users can also install their own certificate package in
their profile. A number of environment variables need to be defined so
that applications and libraries know where to find them. Namely, the
OpenSSL library honors the @code{SSL_CERT_DIR} and @code{SSL_CERT_FILE}
variables. Some applications add their own environment variables; for
instance, the Git version control system honors the certificate bundle
pointed to by the @code{GIT_SSL_CAINFO} environment variable.
@node Name Service Switch
@subsection Name Service Switch
@cindex name service switch
@cindex NSS
The @code{(gnu system nss)} module provides bindings to the
configuration file of libc's @dfn{name service switch} or @dfn{NSS}
(@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
extended with new ``name'' lookup methods for system databases, which
includes host names, service names, user accounts, and more (@pxref{Name
Service Switch, System Databases and Name Service Switch,, libc, The GNU
C Library Reference Manual}).
The NSS configuration specifies, for each system database, which lookup
method is to be used, and how the various methods are chained
together---for instance, under which circumstances NSS should try the
next method in the list. The NSS configuration is given in the
@code{name-service-switch} field of @code{operating-system} declarations
(@pxref{operating-system Reference, @code{name-service-switch}}).
@cindex nss-mdns
@cindex .local, host name lookup
As an example, the declaration below configures the NSS to use the
@uref{http://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
back-end}, which supports host name lookups over multicast DNS (mDNS)
for host names ending in @code{.local}:
@example
(name-service-switch
(hosts (list %files ;first, check /etc/hosts
;; If the above did not succeed, try
;; with 'mdns_minimal'.
(name-service
(name "mdns_minimal")
;; 'mdns_minimal' is authoritative for
;; '.local'. When it returns "not found",
;; no need to try the next methods.
(reaction (lookup-specification
(not-found => return))))
;; Then fall back to DNS.
(name-service
(name "dns"))
;; Finally, try with the "full" 'mdns'.
(name-service
(name "mdns")))))
@end example
Don't worry: the @code{%mdns-host-lookup-nss} variable (see below)
contains this configuration, so you won't have to type it if all you
want is to have @code{.local} host lookup working.
Note that, in this case, in addition to setting the
@code{name-service-switch} of the @code{operating-system} declaration,
you also need to use @code{avahi-service} (@pxref{Networking Services,
@code{avahi-service}}), or @var{%desktop-services}, which includes it
(@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
to the name service cache daemon (@pxref{Base Services,
@code{nscd-service}}).
For convenience, the following variables provide typical NSS
configurations.
@defvr {Scheme Variable} %default-nss
This is the default name service switch configuration, a
@code{name-service-switch} object.
@end defvr
@defvr {Scheme Variable} %mdns-host-lookup-nss
This is the name service switch configuration with support for host name
lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
@end defvr
The reference for name service switch configuration is given below. It
is a direct mapping of the C library's configuration file format, so
please refer to the C library manual for more information (@pxref{NSS
Configuration File,,, libc, The GNU C Library Reference Manual}).
Compared to libc's NSS configuration file format, it has the advantage
not only of adding this warm parenthetic feel that we like, but also
static checks: you'll know about syntax errors and typos as soon as you
run @command{guix system}.
@deftp {Data Type} name-service-switch
This is the data type representation the configuration of libc's name
service switch (NSS). Each field below represents one of the supported
system databases.
@table @code
@item aliases
@itemx ethers
@itemx group
@itemx gshadow
@itemx hosts
@itemx initgroups
@itemx netgroup
@itemx networks
@itemx password
@itemx public-key
@itemx rpc
@itemx services
@itemx shadow
The system databases handled by the NSS. Each of these fields must be a
list of @code{<name-service>} objects (see below.)
@end table
@end deftp
@deftp {Data Type} name-service
This is the data type representing an actual name service and the
associated lookup action.
@table @code
@item name
A string denoting the name service (@pxref{Services in the NSS
configuration,,, libc, The GNU C Library Reference Manual}).
Note that name services listed here must be visible to nscd. This is
achieved by passing the @code{#:name-services} argument to
@code{nscd-service} the list of packages providing the needed name
services (@pxref{Base Services, @code{nscd-service}}).
@item reaction
An action specified using the @code{lookup-specification} macro
(@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
Reference Manual}). For example:
@example
(lookup-specification (unavailable => continue)
(success => return))
@end example
@end table
@end deftp
@node Initial RAM Disk
@subsection Initial RAM Disk
@cindex initial RAM disk (initrd)
@cindex initrd (initial RAM disk)
For bootstrapping purposes, the Linux-Libre kernel is passed an
@dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
root file system, as well as an initialization script. The latter is
responsible for mounting the real root file system, and for loading any
kernel modules that may be needed to achieve that.
The @code{initrd} field of an @code{operating-system} declaration allows
you to specify which initrd you would like to use. The @code{(gnu
system linux-initrd)} module provides two ways to build an initrd: the
high-level @code{base-initrd} procedure, and the low-level
@code{expression->initrd} procedure.
The @code{base-initrd} procedure is intended to cover most common uses.
For example, if you want to add a bunch of kernel modules to be loaded
at boot time, you can define the @code{initrd} field of the operating
system declaration like this:
@example
(initrd (lambda (file-systems . rest)
;; Create a standard initrd that has modules "foo.ko"
;; and "bar.ko", as well as their dependencies, in
;; addition to the modules available by default.
(apply base-initrd file-systems
#:extra-modules '("foo" "bar")
rest)))
@end example
The @code{base-initrd} procedure also handles common use cases that
involves using the system as a QEMU guest, or as a ``live'' system whose
root file system is volatile.
The initial RAM disk produced by @code{base-initrd} honors several
options passed on the Linux kernel command line (that is, arguments
passed @i{via} GRUB's @code{linux} command, or with QEMU's
@code{-append} option), notably:
@table @code
@item --load=@var{boot}
Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
program, once it has mounted the root file system.
GuixSD uses this option to yield control to a boot program that runs the
service activation programs and then spawns GNU@tie{}dmd, the
initialization system.
@item --root=@var{root}
Mount @var{root} as the root file system. @var{root} can be a device
device name like @code{/dev/sda1}, a partition label, or a partition
UUID.
@item --system=@var{system}
Have @file{/run/booted-system} and @file{/run/current-system} point to
@var{system}.
@item modprobe.blacklist=@var{modules}@dots{}
@cindex module, black-listing
@cindex black list, of kernel modules
Instruct the initial RAM disk as well as the @command{modprobe} command
(from the kmod package) to refuse to load @var{modules}. @var{modules}
must be a comma-separated list of module names---e.g.,
@code{usbkbd,9pnet}.
@item --repl
Start a read-eval-print loop (REPL) from the initial RAM disk before it
tries to load kernel modules and to mount the root file system. Our
marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
Manual}, for more information on Guile's REPL.
@end table
Now that you know all the features that initial RAM disks produced by
@code{base-initrd} provide, here is how to use it and customize it
further.
@deffn {Monadic Procedure} base-initrd @var{file-systems} @
[#:qemu-networking? #f] [#:virtio? #f] [#:volatile-root? #f] @
[#:extra-modules '()] [#:mapped-devices '()]
Return a monadic derivation that builds a generic initrd. @var{file-systems} is
a list of file-systems to be mounted by the initrd, possibly in addition to
the root file system specified on the kernel command line via @code{--root}.
@var{mapped-devices} is a list of device mappings to realize before
@var{file-systems} are mounted (@pxref{Mapped Devices}).
When @var{qemu-networking?} is true, set up networking with the standard QEMU
parameters. When @var{virtio?} is true, load additional modules so the initrd can
be used as a QEMU guest with para-virtualized I/O drivers.
When @var{volatile-root?} is true, the root file system is writable but any changes
to it are lost.
The initrd is automatically populated with all the kernel modules necessary
for @var{file-systems} and for the given options. However, additional kernel
modules can be listed in @var{extra-modules}. They will be added to the initrd, and
loaded at boot time in the order in which they appear.
@end deffn
Needless to say, the initrds we produce and use embed a
statically-linked Guile, and the initialization program is a Guile
program. That gives a lot of flexibility. The
@code{expression->initrd} procedure builds such an initrd, given the
program to run in that initrd.
@deffn {Monadic Procedure} expression->initrd @var{exp} @
[#:guile %guile-static-stripped] [#:name "guile-initrd"] @
[#:modules '()]
Return a derivation that builds a Linux initrd (a gzipped cpio archive)
containing @var{guile} and that evaluates @var{exp}, a G-expression,
upon booting. All the derivations referenced by @var{exp} are
automatically copied to the initrd.
@var{modules} is a list of Guile module names to be embedded in the
initrd.
@end deffn
@node GRUB Configuration
@subsection GRUB Configuration
@cindex GRUB
@cindex boot loader
The operating system uses GNU@tie{}GRUB as its boot loader
(@pxref{Overview, overview of GRUB,, grub, GNU GRUB Manual}). It is
configured using @code{grub-configuration} declarations. This data type
is exported by the @code{(gnu system grub)} module, and described below.
@deftp {Data Type} grub-configuration
The type of a GRUB configuration declaration.
@table @asis
@item @code{device}
This is a string denoting the boot device. It must be a device name
understood by the @command{grub-install} command, such as
@code{/dev/sda} or @code{(hd0)} (@pxref{Invoking grub-install,,, grub,
GNU GRUB Manual}).
@item @code{menu-entries} (default: @code{()})
A possibly empty list of @code{menu-entry} objects (see below), denoting
entries to appear in the GRUB boot menu, in addition to the current
system entry and the entry pointing to previous system generations.
@item @code{default-entry} (default: @code{0})
The index of the default boot menu entry. Index 0 is for the current
system's entry.
@item @code{timeout} (default: @code{5})
The number of seconds to wait for keyboard input before booting. Set to
0 to boot immediately, and to -1 to wait indefinitely.
@item @code{theme} (default: @var{%default-theme})
The @code{grub-theme} object describing the theme to use.
@end table
@end deftp
Should you want to list additional boot menu entries @i{via} the
@code{menu-entries} field above, you will need to create them with the
@code{menu-entry} form:
@deftp {Data Type} menu-entry
The type of an entry in the GRUB boot menu.
@table @asis
@item @code{label}
The label to show in the menu---e.g., @code{"GNU"}.
@item @code{linux}
The Linux kernel to boot.
@item @code{linux-arguments} (default: @code{()})
The list of extra Linux kernel command-line arguments---e.g.,
@code{("console=ttyS0")}.
@item @code{initrd}
A G-Expression or string denoting the file name of the initial RAM disk
to use (@pxref{G-Expressions}).
@end table
@end deftp
@c FIXME: Write documentation once it's stable.
Themes are created using the @code{grub-theme} form, which is not
documented yet.
@defvr {Scheme Variable} %default-theme
This is the default GRUB theme used by the operating system, with a
fancy background image displaying the GNU and Guix logos.
@end defvr
@node Invoking guix system
@subsection Invoking @code{guix system}
Once you have written an operating system declaration, as seen in the
previous section, it can be @dfn{instantiated} using the @command{guix
system} command. The synopsis is:
@example
guix system @var{options}@dots{} @var{action} @var{file}
@end example
@var{file} must be the name of a file containing an
@code{operating-system} declaration. @var{action} specifies how the
operating system is instantiate. Currently the following values are
supported:
@table @code
@item reconfigure
Build the operating system described in @var{file}, activate it, and
switch to it@footnote{This action is usable only on systems already
running GuixSD.}.
This effects all the configuration specified in @var{file}: user
accounts, system services, global package list, setuid programs, etc.
It also adds a GRUB menu entry for the new OS configuration, and moves
entries for older configurations to a submenu---unless
@option{--no-grub} is passed.
@c The paragraph below refers to the problem discussed at
@c <http://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
It is highly recommended to run @command{guix pull} once before you run
@command{guix system reconfigure} for the first time (@pxref{Invoking
guix pull}). Failing to do that you would see an older version of Guix
once @command{reconfigure} has completed.
@item build
Build the operating system's derivation, which includes all the
configuration files and programs needed to boot and run the system.
This action does not actually install anything.
@item init
Populate the given directory with all the files necessary to run the
operating system specified in @var{file}. This is useful for first-time
installations of GuixSD. For instance:
@example
guix system init my-os-config.scm /mnt
@end example
copies to @file{/mnt} all the store items required by the configuration
specified in @file{my-os-config.scm}. This includes configuration
files, packages, and so on. It also creates other essential files
needed for the system to operate correctly---e.g., the @file{/etc},
@file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
This command also installs GRUB on the device specified in
@file{my-os-config}, unless the @option{--no-grub} option was passed.
@item vm
@cindex virtual machine
@cindex VM
@anchor{guix system vm}
Build a virtual machine that contain the operating system declared in
@var{file}, and return a script to run that virtual machine (VM).
Arguments given to the script are passed as is to QEMU.
The VM shares its store with the host system.
Additional file systems can be shared between the host and the VM using
the @code{--share} and @code{--expose} command-line options: the former
specifies a directory to be shared with write access, while the latter
provides read-only access to the shared directory.
The example below creates a VM in which the user's home directory is
accessible read-only, and where the @file{/exchange} directory is a
read-write mapping of the host's @file{$HOME/tmp}:
@example
guix system vm my-config.scm \
--expose=$HOME --share=$HOME/tmp=/exchange
@end example
On GNU/Linux, the default is to boot directly to the kernel; this has
the advantage of requiring only a very tiny root disk image since the
host's store can then be mounted.
The @code{--full-boot} option forces a complete boot sequence, starting
with the bootloader. This requires more disk space since a root image
containing at least the kernel, initrd, and bootloader data files must
be created. The @code{--image-size} option can be used to specify the
image's size.
@item vm-image
@itemx disk-image
Return a virtual machine or disk image of the operating system declared
in @var{file} that stands alone. Use the @option{--image-size} option
to specify the size of the image.
When using @code{vm-image}, the returned image is in qcow2 format, which
the QEMU emulator can efficiently use. @xref{Running GuixSD in a VM},
for more information on how to run the image in a virtual machine.
When using @code{disk-image}, a raw disk image is produced; it can be
copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
the device corresponding to a USB stick, one can copy the image on it
using the following command:
@example
# dd if=$(guix system disk-image my-os.scm) of=/dev/sdc
@end example
@item container
Return a script to run the operating system declared in @var{file}
within a container. Containers are a set of lightweight isolation
mechanisms provided by the kernel Linux-libre. Containers are
substantially less resource-demanding than full virtual machines since
the kernel, shared objects, and other resources can be shared with the
host system; this also means they provide thinner isolation.
Currently, the script must be run as root in order to support more than
a single user and group. The container shares its store with the host
system.
As with the @code{vm} action (@pxref{guix system vm}), additional file
systems to be shared between the host and container can be specified
using the @option{--share} and @option{--expose} options:
@example
guix system container my-config.scm \
--expose=$HOME --share=$HOME/tmp=/exchange
@end example
@quotation Note
This option requires Linux-libre 3.19 or newer.
@end quotation
@end table
@var{options} can contain any of the common build options provided by
@command{guix build} (@pxref{Invoking guix build}). In addition,
@var{options} can contain one of the following:
@table @option
@item --system=@var{system}
@itemx -s @var{system}
Attempt to build for @var{system} instead of the host's system type.
This works as per @command{guix build} (@pxref{Invoking guix build}).
@item --derivation
@itemx -d
Return the derivation file name of the given operating system without
building anything.
@item --image-size=@var{size}
For the @code{vm-image} and @code{disk-image} actions, create an image
of the given @var{size}. @var{size} may be a number of bytes, or it may
include a unit as a suffix (@pxref{Block size, size specifications,,
coreutils, GNU Coreutils}).
@item --on-error=@var{strategy}
Apply @var{strategy} when an error occurs when reading @var{file}.
@var{strategy} may be one of the following:
@table @code
@item nothing-special
Report the error concisely and exit. This is the default strategy.
@item backtrace
Likewise, but also display a backtrace.
@item debug
Report the error and enter Guile's debugger. From there, you can run
commands such as @code{,bt} to get a backtrace, @code{,locals} to
display local variable values, and more generally inspect the program's
state. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
a list of available debugging commands.
@end table
@end table
Note that all the actions above, except @code{build} and @code{init},
rely on KVM support in the Linux-Libre kernel. Specifically, the
machine should have hardware virtualization support, the corresponding
KVM kernel module should be loaded, and the @file{/dev/kvm} device node
must exist and be readable and writable by the user and by the daemon's
build users.
Once you have built, configured, re-configured, and re-re-configured
your GuixSD installation, you may find it useful to list the operating
system generations available on disk---and that you can choose from the
GRUB boot menu:
@table @code
@item list-generations
List a summary of each generation of the operating system available on
disk, in a human-readable way. This is similar to the
@option{--list-generations} option of @command{guix package}
(@pxref{Invoking guix package}).
Optionally, one can specify a pattern, with the same syntax that is used
in @command{guix package --list-generations}, to restrict the list of
generations displayed. For instance, the following command displays
generations up to 10-day old:
@example
$ guix system list-generations 10d
@end example
@end table
The @command{guix system} command has even more to offer! The following
sub-commands allow you to visualize how your system services relate to
each other:
@anchor{system-extension-graph}
@table @code
@item extension-graph
Emit in Dot/Graphviz format to standard output the @dfn{service
extension graph} of the operating system defined in @var{file}
(@pxref{Service Composition}, for more information on service
extensions.)
The command:
@example
$ guix system extension-graph @var{file} | dot -Tpdf > services.pdf
@end example
produces a PDF file showing the extension relations among services.
@anchor{system-dmd-graph}
@item dmd-graph
Emit in Dot/Graphviz format to standard output the @dfn{dependency
graph} of dmd services of the operating system defined in @var{file}.
@xref{dmd Services}, for more information and for an example graph.
@end table
@node Running GuixSD in a VM
@subsection Running GuixSD in a VM
One way to run GuixSD in a virtual machine is to build a GuixSD virtual
machine image using @command{guix system vm-image} (@pxref{Invoking guix
system}). The returned image is in qcow2 format, which the
@uref{http://qemu.org/, QEMU emulator} can efficiently use.
To run the image in QEMU, copy it out of the store (@pxref{The Store})
and give yourself permission to write to the copy. When invoking QEMU,
you must choose a system emulator that is suitable for your hardware
platform. Here is a minimal QEMU invocation that will boot the result of
@command{guix system vm-image} on x86_64 hardware:
@example
$ qemu-system-x86_64 \
-net user -net nic,model=virtio \
-enable-kvm -m 256 /tmp/qemu-image
@end example
And the annotated version:
@table @code
@item qemu-system-x86_64
This specifies the hardware platform to emulate. This should match the
host.
@item -net user
Enable the unprivileged user-mode network stack. The guest OS can access
the host but not vice versa. This is the simplest way to get the guest
OS online. If you don't choose a network stack, the boot will fail.
@item -net nic,model=virtio
You must create a network interface of a given model. If you don't
create a NIC, the boot will fail. Assuming your hardware platform is
x86_64, you can get a list of available NIC models by running
`qemu-system-x86_64 -net nic,model=help`.
@item -enable-kvm
If your system has hardware virtualization extensions, enabling the
kernel virtual machine will make things run faster.
@item -m 256
RAM available to the guest OS, in megabytes. Defaults to 128 megabytes,
which is not enough for the Guix daemon.
@item /tmp/qemu-image
The filesystem path of the qcow2 image.
@end table
@node Defining Services
@subsection Defining Services
The previous sections show the available services and how one can combine
them in an @code{operating-system} declaration. But how do we define
them in the first place? And what is a service anyway?
@menu
* Service Composition:: The model for composing services.
* Service Types and Services:: Types and services.
* Service Reference:: API reference.
* dmd Services:: A particular type of service.
@end menu
@node Service Composition
@subsubsection Service Composition
@cindex services
@cindex daemons
Here we define a @dfn{service} as, broadly, something that extends the
operating system's functionality. Often a service is a process---a
@dfn{daemon}---started when the system boots: a secure shell server, a
Web server, the Guix build daemon, etc. Sometimes a service is a daemon
whose execution can be triggered by another daemon---e.g., an FTP server
started by @command{inetd} or a D-Bus service activated by
@command{dbus-daemon}. Occasionally, a service does not map to a
daemon. For instance, the ``account'' service collects user accounts
and makes sure they exist when the system runs; the ``udev'' service
collects device management rules and makes them available to the eudev
daemon; the @file{/etc} service populates the system's @file{/etc}
directory.
@cindex service extensions
GuixSD services are connected by @dfn{extensions}. For instance, the
secure shell service @emph{extends} dmd---GuixSD's initialization system,
running as PID@tie{}1---by giving it the command lines to start and stop
the secure shell daemon (@pxref{Networking Services,
@code{lsh-service}}); the UPower service extends the D-Bus service by
passing it its @file{.service} specification, and extends the udev
service by passing it device management rules (@pxref{Desktop Services,
@code{upower-service}}); the Guix daemon service extends dmd by passing
it the command lines to start and stop the daemon, and extends the
account service by passing it a list of required build user accounts
(@pxref{Base Services}).
All in all, services and their ``extends'' relations form a directed
acyclic graph (DAG). If we represent services as boxes and extensions
as arrows, a typical system might provide something like this:
@image{images/service-graph,,5in,Typical service extension graph.}
@cindex system service
At the bottom, we see the @dfn{system service}, which produces the
directory containing everything to run and boot the system, as returned
by the @command{guix system build} command. @xref{Service Reference},
to learn about the other service types shown here.
@xref{system-extension-graph, the @command{guix system extension-graph}
command}, for information on how to generate this representation for a
particular operating system definition.
@cindex service types
Technically, developers can define @dfn{service types} to express these
relations. There can be any number of services of a given type on the
system---for instance, a system running two instances of the GNU secure
shell server (lsh) has two instances of @var{lsh-service-type}, with
different parameters.
The following section describes the programming interface for service
types and services.
@node Service Types and Services
@subsubsection Service Types and Services
A @dfn{service type} is a node in the DAG described above. Let us start
with a simple example, the service type for the Guix build daemon
(@pxref{Invoking guix-daemon}):
@example
(define guix-service-type
(service-type
(name 'guix)
(extensions
(list (service-extension dmd-root-service-type guix-dmd-service)
(service-extension account-service-type guix-accounts)
(service-extension activation-service-type guix-activation)))))
@end example
@noindent
It defines a two things:
@enumerate
@item
A name, whose sole purpose is to make inspection and debugging easier.
@item
A list of @dfn{service extensions}, where each extension designates the
target service type and a procedure that, given the service's
parameters, returns a list of object to extend the service of that type.
Every service type has at least one service extension. The only
exception is the @dfn{boot service type}, which is the ultimate service.
@end enumerate
In this example, @var{guix-service-type} extends three services:
@table @var
@item dmd-root-service-type
The @var{guix-dmd-service} procedure defines how the dmd service is
extended. Namely, it returns a @code{<dmd-service>} object that defines
how @command{guix-daemon} is started and stopped (@pxref{dmd Services}).
@item account-service-type
This extension for this service is computed by @var{guix-accounts},
which returns a list of @code{user-group} and @code{user-account}
objects representing the build user accounts (@pxref{Invoking
guix-daemon}).
@item activation-service-type
Here @var{guix-activation} is a procedure that returns a gexp, which is
a code snippet to run at ``activation time''---e.g., when the service is
booted.
@end table
A service of this type is instantiated like this:
@example
(service guix-service-type
(guix-configuration
(build-accounts 5)
(use-substitutes? #f)))
@end example
The second argument to the @code{service} form is a value representing
the parameters of this specific service instance.
@xref{guix-configuration-type, @code{guix-configuration}}, for
information about the @code{guix-configuration} data type.
@var{guix-service-type} is quite simple because it extends other
services but is not extensible itself.
@c @subsubsubsection Extensible Service Types
The service type for an @emph{extensible} service looks like this:
@example
(define udev-service-type
(service-type (name 'udev)
(extensions
(list (service-extension dmd-root-service-type
udev-dmd-service)))
(compose concatenate) ;concatenate the list of rules
(extend (lambda (config rules)
(match config
(($ <udev-configuration> udev initial-rules)
(udev-configuration
(udev udev) ;the udev package to use
(rules (append initial-rules rules)))))))))
@end example
This is the service type for the
@uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
management daemon}. Compared to the previous example, in addition to an
extension of @var{dmd-root-service-type}, we see two new fields:
@table @code
@item compose
This is the procedure to @dfn{compose} the list of extensions to
services of this type.
Services can extend the udev service by passing it lists of rules; we
compose those extensions simply by concatenating them.
@item extend
This procedure defines how the service's value is @dfn{extended} with
the composition of the extensions.
Udev extensions are composed into a list of rules, but the udev service
value is itself a @code{<udev-configuration>} record. So here, we
extend that record by appending the list of rules is contains to the
list of contributed rules.
@end table
There can be only one instance of an extensible service type such as
@var{udev-service-type}. If there were more, the
@code{service-extension} specifications would be ambiguous.
Still here? The next section provides a reference of the programming
interface for services.
@node Service Reference
@subsubsection Service Reference
We have seen an overview of service types (@pxref{Service Types and
Services}). This section provides a reference on how to manipulate
services and service types. This interface is provided by the
@code{(gnu services)} module.
@deffn {Scheme Procedure} service @var{type} @var{value}
Return a new service of @var{type}, a @code{<service-type>} object (see
below.) @var{value} can be any object; it represents the parameters of
this particular service instance.
@end deffn
@deffn {Scheme Procedure} service? @var{obj}
Return true if @var{obj} is a service.
@end deffn
@deffn {Scheme Procedure} service-kind @var{service}
Return the type of @var{service}---i.e., a @code{<service-type>} object.
@end deffn
@deffn {Scheme Procedure} service-parameters @var{service}
Return the value associated with @var{service}. It represents its
parameters.
@end deffn
Here is an example of how a service is created and manipulated:
@example
(define s
(service nginx-service-type
(nginx-configuration
(nginx nginx)
(log-directory log-directory)
(run-directory run-directory)
(file config-file))))
(service? s)
@result{} #t
(eq? (service-kind s) nginx-service-type)
@result{} #t
@end example
The @code{modify-services} form provides a handy way to change the
parameters of some of the services of a list such as
@var{%base-services} (@pxref{Base Services, @code{%base-services}}). Of
course, you could always use standard list combinators such as
@code{map} and @code{fold} to do that (@pxref{SRFI-1, List Library,,
guile, GNU Guile Reference Manual}); @code{modify-services} simply
provides a more concise form for this common pattern.
@deffn {Scheme Syntax} modify-services @var{services} @
(@var{type} @var{variable} => @var{body}) @dots{}
Modify the services listed in @var{services} according to the given
clauses. Each clause has the form:
@example
(@var{type} @var{variable} => @var{body})
@end example
where @var{type} is a service type, such as @var{guix-service-type}, and
@var{variable} is an identifier that is bound within @var{body} to the
value of the service of that @var{type}. @xref{Using the Configuration
System}, for an example.
This is a shorthand for:
@example
(map (lambda (service) @dots{}) @var{services})
@end example
@end deffn
Next comes the programming interface for service types. This is
something you want to know when writing new service definitions, but not
necessarily when simply looking for ways to customize your
@code{operating-system} declaration.
@deftp {Data Type} service-type
@cindex service type
This is the representation of a @dfn{service type} (@pxref{Service Types
and Services}).
@table @asis
@item @code{name}
This is a symbol, used only to simplify inspection and debugging.
@item @code{extensions}
A non-empty list of @code{<service-extension>} objects (see below.)
@item @code{compose} (default: @code{#f})
If this is @code{#f}, then the service type denotes services that cannot
be extended---i.e., services that do not receive ``values'' from other
services.
Otherwise, it must be a one-argument procedure. The procedure is called
by @code{fold-services} and is passed a list of values collected from
extensions. It must return a value that is a valid parameter value for
the service instance.
@item @code{extend} (default: @code{#f})
If this is @code{#f}, services of this type cannot be extended.
Otherwise, it must be a two-argument procedure: @code{fold-services}
calls it, passing it the service's initial value as the first argument
and the result of applying @code{compose} to the extension values as the
second argument.
@end table
@xref{Service Types and Services}, for examples.
@end deftp
@deffn {Scheme Procedure} service-extension @var{target-type} @
@var{compute}
Return a new extension for services of type @var{target-type}.
@var{compute} must be a one-argument procedure: @code{fold-services}
calls it, passing it the value associated with the service that provides
the extension; it must return a valid value for the target service.
@end deffn
@deffn {Scheme Procedure} service-extension? @var{obj}
Return true if @var{obj} is a service extension.
@end deffn
At the core of the service abstraction lies the @code{fold-services}
procedure, which is responsible for ``compiling'' a list of services
down to a single directory that contains everything needed to boot and
run the system---the directory shown by the @command{guix system build}
command (@pxref{Invoking guix system}). In essence, it propagates
service extensions down the service graph, updating each node parameters
on the way, until it reaches the root node.
@deffn {Scheme Procedure} fold-services @var{services} @
[#:target-type @var{system-service-type}]
Fold @var{services} by propagating their extensions down to the root of
type @var{target-type}; return the root service adjusted accordingly.
@end deffn
Lastly, the @code{(gnu services)} module also defines several essential
service types, some of which are listed below.
@defvr {Scheme Variable} system-service-type
This is the root of the service graph. It produces the system directory
as returned by the @command{guix system build} command.
@end defvr
@defvr {Scheme Variable} boot-service-type
The type of the ``boot service'', which produces the @dfn{boot script}.
The boot script is what the initial RAM disk runs when booting.
@end defvr
@defvr {Scheme Variable} etc-service-type
The type of the @file{/etc} service. This service can be extended by
passing it name/file tuples such as:
@example
(list `("issue" ,(plain-file "issue" "Welcome!\n")))
@end example
In this example, the effect would be to add an @file{/etc/issue} file
pointing to the given file.
@end defvr
@defvr {Scheme Variable} setuid-program-service-type
Type for the ``setuid-program service''. This service collects lists of
executable file names, passed as gexps, and adds them to the set of
setuid-root programs on the system (@pxref{Setuid Programs}).
@end defvr
@defvr {Scheme Variable} profile-service-type
Type of the service that populates the @dfn{system profile}---i.e., the
programs under @file{/run/current-system/profile}. Other services can
extend it by passing it lists of packages to add to the system profile.
@end defvr
@node dmd Services
@subsubsection dmd Services
@cindex PID 1
@cindex init system
The @code{(gnu services dmd)} provides a way to define services managed
by GNU@tie{}dmd, which is GuixSD initialization system---the first
process that is started when the system boots, aka. PID@tie{}1
(@pxref{Introduction,,, dmd, GNU dmd Manual}).
Services in dmd can depend on each other. For instance, the SSH daemon
may need to be started after the syslog daemon has been started, which
in turn can only happen once all the file systems have been mounted.
The simple operating system defined earlier (@pxref{Using the
Configuration System}) results in a service graph like this:
@image{images/dmd-graph,,5in,Typical dmd service graph.}
You can actually generate such a graph for any operating system
definition using the @command{guix system dmd-graph} command
(@pxref{system-dmd-graph, @command{guix system dmd-graph}}).
The @var{%dmd-root-service} is a service object representing PID@tie{}1,
of type @var{dmd-root-service-type}; it can be extended by passing it
lists of @code{<dmd-service>} objects.
@deftp {Data Type} dmd-service
The data type representing a service managed by dmd.
@table @asis
@item @code{provision}
This is a list of symbols denoting what the service provides.
These are the names that may be passed to @command{deco start},
@command{deco status}, and similar commands (@pxref{Invoking deco,,,
dmd, GNU dmd Manual}). @xref{Slots of services, the @code{provides}
slot,, dmd, GNU dmd Manual}, for details.
@item @code{requirements} (default: @code{'()})
List of symbols denoting the dmd services this one depends on.
@item @code{respawn?} (default: @code{#t})
Whether to restart the service when it stops, for instance when the
underlying process dies.
@item @code{start}
@itemx @code{stop} (default: @code{#~(const #f)})
The @code{start} and @code{stop} fields refer to dmd's facilities to
start and stop processes (@pxref{Service De- and Constructors,,, dmd,
GNU dmd Manual}). They are given as G-expressions that get expanded in
the dmd configuration file (@pxref{G-Expressions}).
@item @code{documentation}
A documentation string, as shown when running:
@example
deco doc @var{service-name}
@end example
where @var{service-name} is one of the symbols in @var{provision}
(@pxref{Invoking deco,,, dmd, GNU dmd Manual}).
@item @code{modules} (default: @var{%default-modules})
This is the list of modules that must be in scope when @code{start} and
@code{stop} are evaluated.
@item @code{imported-modules} (default: @var{%default-imported-modules})
This is the list of modules to import in the execution environment of
dmd.
@end table
@end deftp
@defvr {Scheme Variable} dmd-root-service-type
The service type for the dmd ``root service''---i.e., PID@tie{}1.
This is the service type that extensions target when they want to create
dmd services (@pxref{Service Types and Services}, for an example). Each
extension must pass a list of @code{<dmd-service>}.
@end defvr
@defvr {Scheme Variable} %dmd-root-service
This service represents PID@tie{}1.
@end defvr
@node Installing Debugging Files
@section Installing Debugging Files
@cindex debugging files
Program binaries, as produced by the GCC compilers for instance, are
typically written in the ELF format, with a section containing
@dfn{debugging information}. Debugging information is what allows the
debugger, GDB, to map binary code to source code; it is required to
debug a compiled program in good conditions.
The problem with debugging information is that is takes up a fair amount
of disk space. For example, debugging information for the GNU C Library
weighs in at more than 60 MiB. Thus, as a user, keeping all the
debugging info of all the installed programs is usually not an option.
Yet, space savings should not come at the cost of an impediment to
debugging---especially in the GNU system, which should make it easier
for users to exert their computing freedom (@pxref{GNU Distribution}).
Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
mechanism that allows users to get the best of both worlds: debugging
information can be stripped from the binaries and stored in separate
files. GDB is then able to load debugging information from those files,
when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
with GDB}).
The GNU distribution takes advantage of this by storing debugging
information in the @code{lib/debug} sub-directory of a separate package
output unimaginatively called @code{debug} (@pxref{Packages with
Multiple Outputs}). Users can choose to install the @code{debug} output
of a package when they need it. For instance, the following command
installs the debugging information for the GNU C Library and for GNU
Guile:
@example
guix package -i glibc:debug guile:debug
@end example
GDB must then be told to look for debug files in the user's profile, by
setting the @code{debug-file-directory} variable (consider setting it
from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
GDB}):
@example
(gdb) set debug-file-directory ~/.guix-profile/lib/debug
@end example
From there on, GDB will pick up debugging information from the
@code{.debug} files under @file{~/.guix-profile/lib/debug}.
In addition, you will most likely want GDB to be able to show the source
code being debugged. To do that, you will have to unpack the source
code of the package of interest (obtained with @code{guix build
--source}, @pxref{Invoking guix build}), and to point GDB to that source
directory using the @code{directory} command (@pxref{Source Path,
@code{directory},, gdb, Debugging with GDB}).
@c XXX: keep me up-to-date
The @code{debug} output mechanism in Guix is implemented by the
@code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
opt-in---debugging information is available only for those packages
whose definition explicitly declares a @code{debug} output. This may be
changed to opt-out in the future, if our build farm servers can handle
the load. To check whether a package has a @code{debug} output, use
@command{guix package --list-available} (@pxref{Invoking guix package}).
@node Security Updates
@section Security Updates
@quotation Note
As of version @value{VERSION}, the feature described in this section is
experimental.
@end quotation
@cindex security updates
Occasionally, important security vulnerabilities are discovered in core
software packages and must be patched. Guix follows a functional
package management discipline (@pxref{Introduction}), which implies
that, when a package is changed, @emph{every package that depends on it}
must be rebuilt. This can significantly slow down the deployment of
fixes in core packages such as libc or Bash, since basically the whole
distribution would need to be rebuilt. Using pre-built binaries helps
(@pxref{Substitutes}), but deployment may still take more time than
desired.
@cindex grafts
To address that, Guix implements @dfn{grafts}, a mechanism that allows
for fast deployment of critical updates without the costs associated
with a whole-distribution rebuild. The idea is to rebuild only the
package that needs to be patched, and then to ``graft'' it onto packages
explicitly installed by the user and that were previously referring to
the original package. The cost of grafting is typically very low, and
order of magnitudes lower than a full rebuild of the dependency chain.
@cindex replacements of packages, for grafts
For instance, suppose a security update needs to be applied to Bash.
Guix developers will provide a package definition for the ``fixed''
Bash, say @var{bash-fixed}, in the usual way (@pxref{Defining
Packages}). Then, the original package definition is augmented with a
@code{replacement} field pointing to the package containing the bug fix:
@example
(define bash
(package
(name "bash")
;; @dots{}
(replacement bash-fixed)))
@end example
From there on, any package depending directly or indirectly on Bash that
is installed will automatically be ``rewritten'' to refer to
@var{bash-fixed} instead of @var{bash}. This grafting process takes
time proportional to the size of the package, but expect less than a
minute for an ``average'' package on a recent machine.
Currently, the graft and the package it replaces (@var{bash-fixed} and
@var{bash} in the example above) must have the exact same @code{name}
and @code{version} fields. This restriction mostly comes from the fact
that grafting works by patching files, including binary files, directly.
Other restrictions may apply: for instance, when adding a graft to a
package providing a shared library, the original shared library and its
replacement must have the same @code{SONAME} and be binary-compatible.
@node Package Modules
@section Package Modules
From a programming viewpoint, the package definitions of the
GNU distribution are provided by Guile modules in the @code{(gnu packages
@dots{})} name space@footnote{Note that packages under the @code{(gnu
packages @dots{})} module name space are not necessarily ``GNU
packages''. This module naming scheme follows the usual Guile module
naming convention: @code{gnu} means that these modules are distributed
as part of the GNU system, and @code{packages} identifies modules that
define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
Reference Manual}). For instance, the @code{(gnu packages emacs)}
module exports a variable named @code{emacs}, which is bound to a
@code{<package>} object (@pxref{Defining Packages}).
The @code{(gnu packages @dots{})} module name space is
automatically scanned for packages by the command-line tools. For
instance, when running @code{guix package -i emacs}, all the @code{(gnu
packages @dots{})} modules are scanned until one that exports a package
object whose name is @code{emacs} is found. This package search
facility is implemented in the @code{(gnu packages)} module.
@cindex customization, of packages
@cindex package module search path
Users can store package definitions in modules with different
names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
name and module name must match. For instance, the @code{(my-packages
emacs)} module must be stored in a @file{my-packages/emacs.scm} file
relative to the load path specified with @option{--load-path} or
@code{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
guile, GNU Guile Reference Manual}, for details.}. These package definitions
will not be visible by default. Thus, users can invoke commands such as
@command{guix package} and @command{guix build} have to be used with the
@code{-e} option so that they know where to find the package. Better
yet, they can use the
@code{-L} option of these commands to make those modules visible
(@pxref{Invoking guix build, @code{--load-path}}), or define the
@code{GUIX_PACKAGE_PATH} environment variable. This environment
variable makes it easy to extend or customize the distribution and is
honored by all the user interfaces.
@defvr {Environment Variable} GUIX_PACKAGE_PATH
This is a colon-separated list of directories to search for package
modules. Directories listed in this variable take precedence over the
distribution's own modules.
@end defvr
The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
each package is built based solely on other packages in the
distribution. The root of this dependency graph is a small set of
@dfn{bootstrap binaries}, provided by the @code{(gnu packages
bootstrap)} module. For more information on bootstrapping,
@pxref{Bootstrapping}.
@node Packaging Guidelines
@section Packaging Guidelines
The GNU distribution is nascent and may well lack some of your favorite
packages. This section describes how you can help make the distribution
grow. @xref{Contributing}, for additional information on how you can
help.
Free software packages are usually distributed in the form of
@dfn{source code tarballs}---typically @file{tar.gz} files that contain
all the source files. Adding a package to the distribution means
essentially two things: adding a @dfn{recipe} that describes how to
build the package, including a list of other packages required to build
it, and adding @dfn{package meta-data} along with that recipe, such as a
description and licensing information.
In Guix all this information is embodied in @dfn{package definitions}.
Package definitions provide a high-level view of the package. They are
written using the syntax of the Scheme programming language; in fact,
for each package we define a variable bound to the package definition,
and export that variable from a module (@pxref{Package Modules}).
However, in-depth Scheme knowledge is @emph{not} a prerequisite for
creating packages. For more information on package definitions,
@pxref{Defining Packages}.
Once a package definition is in place, stored in a file in the Guix
source tree, it can be tested using the @command{guix build} command
(@pxref{Invoking guix build}). For example, assuming the new package is
called @code{gnew}, you may run this command from the Guix build tree
(@pxref{Running Guix Before It Is Installed}):
@example
./pre-inst-env guix build gnew --keep-failed
@end example
Using @code{--keep-failed} makes it easier to debug build failures since
it provides access to the failed build tree. Another useful
command-line option when debugging is @code{--log-file}, to access the
build log.
If the package is unknown to the @command{guix} command, it may be that
the source file contains a syntax error, or lacks a @code{define-public}
clause to export the package variable. To figure it out, you may load
the module from Guile to get more information about the actual error:
@example
./pre-inst-env guile -c '(use-modules (gnu packages gnew))'
@end example
Once your package builds correctly, please send us a patch
(@pxref{Contributing}). Well, if you need help, we will be happy to
help you too. Once the patch is committed in the Guix repository, the
new package automatically gets built on the supported platforms by
@url{http://hydra.gnu.org/jobset/gnu/master, our continuous integration
system}.
@cindex substituter
Users can obtain the new package definition simply by running
@command{guix pull} (@pxref{Invoking guix pull}). When
@code{hydra.gnu.org} is done building the package, installing the
package automatically downloads binaries from there
(@pxref{Substitutes}). The only place where human intervention is
needed is to review and apply the patch.
@menu
* Software Freedom:: What may go into the distribution.
* Package Naming:: What's in a name?
* Version Numbers:: When the name is not enough.
* Synopses and Descriptions:: Helping users find the right package.
* Python Modules:: Taming the snake.
* Perl Modules:: Little pearls.
* Fonts:: Fond of fonts.
@end menu
@node Software Freedom
@subsection Software Freedom
@c Adapted from http://www.gnu.org/philosophy/philosophy.html.
The GNU operating system has been developed so that users can have
freedom in their computing. GNU is @dfn{free software}, meaning that
users have the @url{http://www.gnu.org/philosophy/free-sw.html,four
essential freedoms}: to run the program, to study and change the program
in source code form, to redistribute exact copies, and to distribute
modified versions. Packages found in the GNU distribution provide only
software that conveys these four freedoms.
In addition, the GNU distribution follow the
@url{http://www.gnu.org/distros/free-system-distribution-guidelines.html,free
software distribution guidelines}. Among other things, these guidelines
reject non-free firmware, recommendations of non-free software, and
discuss ways to deal with trademarks and patents.
Some packages contain a small and optional subset that violates the
above guidelines, for instance because this subset is itself non-free
code. When that happens, the offending items are removed with
appropriate patches or code snippets in the package definition's
@code{origin} form (@pxref{Defining Packages}). That way, @code{guix
build --source} returns the ``freed'' source rather than the unmodified
upstream source.
@node Package Naming
@subsection Package Naming
A package has actually two names associated with it:
First, there is the name of the @emph{Scheme variable}, the one following
@code{define-public}. By this name, the package can be made known in the
Scheme code, for instance as input to another package. Second, there is
the string in the @code{name} field of a package definition. This name
is used by package management commands such as
@command{guix package} and @command{guix build}.
Both are usually the same and correspond to the lowercase conversion of
the project name chosen upstream, with underscores replaced with
hyphens. For instance, GNUnet is available as @code{gnunet}, and
SDL_net as @code{sdl-net}.
We do not add @code{lib} prefixes for library packages, unless these are
already part of the official project name. But @pxref{Python
Modules} and @ref{Perl Modules} for special rules concerning modules for
the Python and Perl languages.
Font package names are handled differently, @pxref{Fonts}.
@node Version Numbers
@subsection Version Numbers
We usually package only the latest version of a given free software
project. But sometimes, for instance for incompatible library versions,
two (or more) versions of the same package are needed. These require
different Scheme variable names. We use the name as defined
in @ref{Package Naming}
for the most recent version; previous versions use the same name, suffixed
by @code{-} and the smallest prefix of the version number that may
distinguish the two versions.
The name inside the package definition is the same for all versions of a
package and does not contain any version number.
For instance, the versions 2.24.20 and 3.9.12 of GTK+ may be packaged as follows:
@example
(define-public gtk+
(package
(name "gtk+")
(version "3.9.12")
...))
(define-public gtk+-2
(package
(name "gtk+")
(version "2.24.20")
...))
@end example
If we also wanted GTK+ 3.8.2, this would be packaged as
@example
(define-public gtk+-3.8
(package
(name "gtk+")
(version "3.8.2")
...))
@end example
@node Synopses and Descriptions
@subsection Synopses and Descriptions
As we have seen before, each package in GNU@tie{}Guix includes a
synopsis and a description (@pxref{Defining Packages}). Synopses and
descriptions are important: They are what @command{guix package
--search} searches, and a crucial piece of information to help users
determine whether a given package suits their needs. Consequently,
packagers should pay attention to what goes into them.
Synopses must start with a capital letter and must not end with a
period. They must not start with ``a'' or ``the'', which usually does
not bring anything; for instance, prefer ``File-frobbing tool'' over ``A
tool that frobs files''. The synopsis should say what the package
is---e.g., ``Core GNU utilities (file, text, shell)''---or what it is
used for---e.g., the synopsis for GNU@tie{}grep is ``Print lines
matching a pattern''.
Keep in mind that the synopsis must be meaningful for a very wide
audience. For example, ``Manipulate alignments in the SAM format''
might make sense for a seasoned bioinformatics researcher, but might be
fairly unhelpful or even misleading to a non-specialized audience. It
is a good idea to come up with a synopsis that gives an idea of the
application domain of the package. In this example, this might give
something like ``Manipulate nucleotide sequence alignments'', which
hopefully gives the user a better idea of whether this is what they are
looking for.
@cindex Texinfo markup, in package descriptions
Descriptions should take between five and ten lines. Use full
sentences, and avoid using acronyms without first introducing them.
Descriptions can include Texinfo markup, which is useful to introduce
ornaments such as @code{@@code} or @code{@@dfn}, bullet lists, or
hyperlinks (@pxref{Overview,,, texinfo, GNU Texinfo}). However you
should be careful when using some characters for example @samp{@@} and
curly braces which are the basic special characters in Texinfo
(@pxref{Special Characters,,, texinfo, GNU Texinfo}). User interfaces
such as @command{guix package --show} take care of rendering it
appropriately.
Synopses and descriptions are translated by volunteers
@uref{http://translationproject.org/domain/guix-packages.html, at the
Translation Project} so that as many users as possible can read them in
their native language. User interfaces search them and display them in
the language specified by the current locale.
Translation is a lot of work so, as a packager, please pay even more
attention to your synopses and descriptions as every change may entail
additional work for translators. In order to help them, it is possible
to make recommendations or instructions visible to them by inserting
special comments like this (@pxref{xgettext Invocation,,, gettext, GNU
Gettext}):
@example
;; TRANSLATORS: "X11 resize-and-rotate" should not be translated.
(description "ARandR is designed to provide a simple visual front end
for the X11 resize-and-rotate (RandR) extension. @dots{}")
@end example
@node Python Modules
@subsection Python Modules
We currently package Python 2 and Python 3, under the Scheme variable names
@code{python-2} and @code{python} as explained in @ref{Version Numbers}.
To avoid confusion and naming clashes with other programming languages, it
seems desirable that the name of a package for a Python module contains
the word @code{python}.
Some modules are compatible with only one version of Python, others with both.
If the package Foo compiles only with Python 3, we name it
@code{python-foo}; if it compiles only with Python 2, we name it
@code{python2-foo}. If it is compatible with both versions, we create two
packages with the corresponding names.
If a project already contains the word @code{python}, we drop this;
for instance, the module python-dateutil is packaged under the names
@code{python-dateutil} and @code{python2-dateutil}.
@node Perl Modules
@subsection Perl Modules
Perl programs standing for themselves are named as any other package,
using the lowercase upstream name.
For Perl packages containing a single class, we use the lowercase class name,
replace all occurrences of @code{::} by dashes and prepend the prefix
@code{perl-}.
So the class @code{XML::Parser} becomes @code{perl-xml-parser}.
Modules containing several classes keep their lowercase upstream name and
are also prepended by @code{perl-}. Such modules tend to have the word
@code{perl} somewhere in their name, which gets dropped in favor of the
prefix. For instance, @code{libwww-perl} becomes @code{perl-libwww}.
@node Fonts
@subsection Fonts
For fonts that are in general not installed by a user for typesetting
purposes, or that are distributed as part of a larger software package,
we rely on the general packaging rules for software; for instance, this
applies to the fonts delivered as part of the X.Org system or fonts that
are part of TeX Live.
To make it easier for a user to search for fonts, names for other packages
containing only fonts are constructed as follows, independently of the
upstream package name.
The name of a package containing only one font family starts with
@code{font-}; it is followed by the foundry name and a dash @code{-}
if the foundry is known, and the font family name, in which spaces are
replaced by dashes (and as usual, all upper case letters are transformed
to lower case).
For example, the Gentium font family by SIL is packaged under the name
@code{font-sil-gentium}.
For a package containing several font families, the name of the collection
is used in the place of the font family name.
For instance, the Liberation fonts consist of three families,
Liberation Sans, Liberation Serif and Liberation Mono.
These could be packaged separately under the names
@code{font-liberation-sans} and so on; but as they are distributed together
under a common name, we prefer to package them together as
@code{font-liberation}.
In the case where several formats of the same font family or font collection
are packaged separately, a short form of the format, prepended by a dash,
is added to the package name. We use @code{-ttf} for TrueType fonts,
@code{-otf} for OpenType fonts and @code{-type1} for PostScript Type 1
fonts.
@node Bootstrapping
@section Bootstrapping
@c Adapted from the ELS 2013 paper.
@cindex bootstrapping
Bootstrapping in our context refers to how the distribution gets built
``from nothing''. Remember that the build environment of a derivation
contains nothing but its declared inputs (@pxref{Introduction}). So
there's an obvious chicken-and-egg problem: how does the first package
get built? How does the first compiler get compiled? Note that this is
a question of interest only to the curious hacker, not to the regular
user, so you can shamelessly skip this section if you consider yourself
a ``regular user''.
@cindex bootstrap binaries
The GNU system is primarily made of C code, with libc at its core. The
GNU build system itself assumes the availability of a Bourne shell and
command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
`grep'. Furthermore, build programs---programs that run
@code{./configure}, @code{make}, etc.---are written in Guile Scheme
(@pxref{Derivations}). Consequently, to be able to build anything at
all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
Binutils, libc, and the other packages mentioned above---the
@dfn{bootstrap binaries}.
These bootstrap binaries are ``taken for granted'', though we can also
re-create them if needed (more on that later).
@unnumberedsubsec Preparing to Use the Bootstrap Binaries
@c As of Emacs 24.3, Info-mode displays the image, but since it's a
@c large image, it's hard to scroll. Oh well.
@image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
The figure above shows the very beginning of the dependency graph of the
distribution, corresponding to the package definitions of the @code{(gnu
packages bootstrap)} module. A similar figure can be generated with
@command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
@example
guix graph -t derivation \
-e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
| dot -Tps > t.ps
@end example
At this level of detail, things are
slightly complex. First, Guile itself consists of an ELF executable,
along with many source and compiled Scheme files that are dynamically
loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
tarball shown in this graph. This tarball is part of Guix's ``source''
distribution, and gets inserted into the store with @code{add-to-store}
(@pxref{The Store}).
But how do we write a derivation that unpacks this tarball and adds it
to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
derivation---the first one that gets built---uses @code{bash} as its
builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
@code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
@file{xz}, and @file{mkdir} are statically-linked binaries, also part of
the Guix source distribution, whose sole purpose is to allow the Guile
tarball to be unpacked.
Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
Guile that can be used to run subsequent build programs. Its first task
is to download tarballs containing the other pre-built binaries---this
is what the @code{.tar.xz.drv} derivations do. Guix modules such as
@code{ftp-client.scm} are used for this purpose. The
@code{module-import.drv} derivations import those modules in a directory
in the store, using the original layout. The
@code{module-import-compiled.drv} derivations compile those modules, and
write them in an output directory with the right layout. This
corresponds to the @code{#:modules} argument of
@code{build-expression->derivation} (@pxref{Derivations}).
Finally, the various tarballs are unpacked by the
derivations @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv},
etc., at which point we have a working C tool chain.
@unnumberedsubsec Building the Build Tools
Bootstrapping is complete when we have a full tool chain that does not
depend on the pre-built bootstrap tools discussed above. This
no-dependency requirement is verified by checking whether the files of
the final tool chain contain references to the @file{/gnu/store}
directories of the bootstrap inputs. The process that leads to this
``final'' tool chain is described by the package definitions found in
the @code{(gnu packages commencement)} module.
The @command{guix graph} command allows us to ``zoom out'' compared to
the graph above, by looking at the level of package objects instead of
individual derivations---remember that a package may translate to
several derivations, typically one derivation to download its source,
one to build the Guile modules it needs, and one to actually build the
package from source. The command:
@example
guix graph -t bag \
-e '(@@@@ (gnu packages commencement)
glibc-final-with-bootstrap-bash)' | dot -Tps > t.ps
@end example
@noindent
produces the dependency graph leading to the ``final'' C
library@footnote{You may notice the @code{glibc-intermediate} label,
suggesting that it is not @emph{quite} final, but as a good
approximation, we will consider it final.}, depicted below.
@image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
@c See <http://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
The first tool that gets built with the bootstrap binaries is
GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
for all the following packages. From there Findutils and Diffutils get
built.
Then come the first-stage Binutils and GCC, built as pseudo cross
tools---i.e., with @code{--target} equal to @code{--host}. They are
used to build libc. Thanks to this cross-build trick, this libc is
guaranteed not to hold any reference to the initial tool chain.
From there the final Binutils and GCC (not shown above) are built.
GCC uses @code{ld}
from the final Binutils, and links programs against the just-built libc.
This tool chain is used to build the other packages used by Guix and by
the GNU Build System: Guile, Bash, Coreutils, etc.
And voilà! At this point we have the complete set of build tools that
the GNU Build System expects. These are in the @code{%final-inputs}
variable of the @code{(gnu packages commencement)} module, and are
implicitly used by any package that uses @code{gnu-build-system}
(@pxref{Build Systems, @code{gnu-build-system}}).
@unnumberedsubsec Building the Bootstrap Binaries
Because the final tool chain does not depend on the bootstrap binaries,
those rarely need to be updated. Nevertheless, it is useful to have an
automated way to produce them, should an update occur, and this is what
the @code{(gnu packages make-bootstrap)} module provides.
The following command builds the tarballs containing the bootstrap
binaries (Guile, Binutils, GCC, libc, and a tarball containing a mixture
of Coreutils and other basic command-line tools):
@example
guix build bootstrap-tarballs
@end example
The generated tarballs are those that should be referred to in the
@code{(gnu packages bootstrap)} module mentioned at the beginning of
this section.
Still here? Then perhaps by now you've started to wonder: when do we
reach a fixed point? That is an interesting question! The answer is
unknown, but if you would like to investigate further (and have
significant computational and storage resources to do so), then let us
know.
@node Porting
@section Porting to a New Platform
As discussed above, the GNU distribution is self-contained, and
self-containment is achieved by relying on pre-built ``bootstrap
binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
operating system kernel, CPU architecture, and application binary
interface (ABI). Thus, to port the distribution to a platform that is
not yet supported, one must build those bootstrap binaries, and update
the @code{(gnu packages bootstrap)} module to use them on that platform.
Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
When everything goes well, and assuming the GNU tool chain supports the
target platform, this can be as simple as running a command like this
one:
@example
guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
@end example
For this to work, the @code{glibc-dynamic-linker} procedure in
@code{(gnu packages bootstrap)} must be augmented to return the right
file name for libc's dynamic linker on that platform; likewise,
@code{system->linux-architecture} in @code{(gnu packages linux)} must be
taught about the new platform.
Once these are built, the @code{(gnu packages bootstrap)} module needs
to be updated to refer to these binaries on the target platform. That
is, the hashes and URLs of the bootstrap tarballs for the new platform
must be added alongside those of the currently supported platforms. The
bootstrap Guile tarball is treated specially: it is expected to be
available locally, and @file{gnu-system.am} has rules do download it for
the supported architectures; a rule for the new platform must be added
as well.
In practice, there may be some complications. First, it may be that the
extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
above) is not recognized by all the GNU tools. Typically, glibc
recognizes some of these, whereas GCC uses an extra @code{--with-abi}
configure flag (see @code{gcc.scm} for examples of how to handle this).
Second, some of the required packages could fail to build for that
platform. Lastly, the generated binaries could be broken for some
reason.
@c *********************************************************************
@include contributing.texi
@c *********************************************************************
@node Acknowledgments
@chapter Acknowledgments
Guix is based on the @uref{http://nixos.org/nix/, Nix package manager},
which was designed and
implemented by Eelco Dolstra, with contributions from other people (see
the @file{nix/AUTHORS} file in Guix.) Nix pioneered functional package
management, and promoted unprecedented features, such as transactional
package upgrades and rollbacks, per-user profiles, and referentially
transparent build processes. Without this work, Guix would not exist.
The Nix-based software distributions, Nixpkgs and NixOS, have also been
an inspiration for Guix.
GNU@tie{}Guix itself is a collective work with contributions from a
number of people. See the @file{AUTHORS} file in Guix for more
information on these fine people. The @file{THANKS} file lists people
who have helped by reporting bugs, taking care of the infrastructure,
providing artwork and themes, making suggestions, and more---thank you!
@c *********************************************************************
@node GNU Free Documentation License
@appendix GNU Free Documentation License
@include fdl-1.3.texi
@c *********************************************************************
@node Concept Index
@unnumbered Concept Index
@printindex cp
@node Programming Index
@unnumbered Programming Index
@syncodeindex tp fn
@syncodeindex vr fn
@printindex fn
@bye
@c Local Variables:
@c ispell-local-dictionary: "american";
@c End:
|