unofficial mirror of guix-patches@gnu.org 
 help / color / mirror / code / Atom feed
blob 872931840aa96806b815af7953b9241f13036d77 45880 bytes (raw)
name: guix/scripts/publish.scm 	 # note: path name is non-authoritative(*)

   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
 
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2015 David Thompson <davet@gnu.org>
;;; Copyright © 2015, 2016, 2017, 2018, 2019, 2020 Ludovic Courtès <ludo@gnu.org>
;;;
;;; This file is part of GNU Guix.
;;;
;;; GNU Guix is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 3 of the License, or (at
;;; your option) any later version.
;;;
;;; GNU Guix is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.

(define-module (guix scripts publish)
  #:use-module ((system repl server) #:prefix repl:)
  #:use-module (ice-9 binary-ports)
  #:use-module (ice-9 format)
  #:use-module (ice-9 match)
  #:use-module (ice-9 regex)
  #:use-module (ice-9 rdelim)
  #:use-module (ice-9 threads)
  #:use-module (rnrs bytevectors)
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-2)
  #:use-module (srfi srfi-9)
  #:use-module (srfi srfi-9 gnu)
  #:use-module (srfi srfi-19)
  #:use-module (srfi srfi-26)
  #:use-module (srfi srfi-34)
  #:use-module (srfi srfi-37)
  #:use-module (web http)
  #:use-module (web request)
  #:use-module (web response)
  #:use-module (web server)
  #:use-module (web uri)
  #:autoload   (sxml simple) (sxml->xml)
  #:use-module (guix base32)
  #:use-module (guix base64)
  #:use-module (guix config)
  #:use-module (guix derivations)
  #:use-module (gcrypt hash)
  #:use-module (guix pki)
  #:use-module (gcrypt pk-crypto)
  #:use-module (guix workers)
  #:use-module (guix store)
  #:use-module ((guix serialization) #:select (write-file))
  #:use-module (zlib)
  #:autoload   (lzlib) (call-with-lzip-output-port
                        make-lzip-output-port)
  #:use-module (guix cache)
  #:use-module (guix ui)
  #:use-module (guix scripts)
  #:use-module ((guix utils)
                #:select (with-atomic-file-output compressed-file?))
  #:use-module ((guix build utils)
                #:select (dump-port mkdir-p find-files))
  #:use-module ((guix build syscalls) #:select (set-thread-name))
  #:export (%public-key
            %private-key
            signed-string

            guix-publish))

(define (show-help)
  (format #t (G_ "Usage: guix publish [OPTION]...
Publish ~a over HTTP.\n") %store-directory)
  (display (G_ "
  -p, --port=PORT        listen on PORT"))
  (display (G_ "
      --listen=HOST      listen on the network interface for HOST"))
  (display (G_ "
  -u, --user=USER        change privileges to USER as soon as possible"))
  (display (G_ "
  -C, --compression[=METHOD:LEVEL]
                         compress archives with METHOD at LEVEL"))
  (display (G_ "
  -c, --cache=DIRECTORY  cache published items to DIRECTORY"))
  (display (G_ "
      --workers=N        use N workers to bake items"))
  (display (G_ "
      --ttl=TTL          announce narinfos can be cached for TTL seconds"))
  (display (G_ "
      --nar-path=PATH    use PATH as the prefix for nar URLs"))
  (display (G_ "
      --public-key=FILE  use FILE as the public key for signatures"))
  (display (G_ "
      --private-key=FILE use FILE as the private key for signatures"))
  (display (G_ "
  -r, --repl[=PORT]      spawn REPL server on PORT"))
  (newline)
  (display (G_ "
  -h, --help             display this help and exit"))
  (display (G_ "
  -V, --version          display version information and exit"))
  (newline)
  (show-bug-report-information))

(define (getaddrinfo* host)
  "Like 'getaddrinfo', but properly report errors."
  (catch 'getaddrinfo-error
    (lambda ()
      (getaddrinfo host))
    (lambda (key error)
      (leave (G_ "lookup of host '~a' failed: ~a~%")
             host (gai-strerror error)))))

;; Nar compression parameters.
(define-record-type <compression>
  (compression type level)
  compression?
  (type   compression-type)
  (level  compression-level))

(define %no-compression
  (compression 'none 0))

(define %default-gzip-compression
  ;; Since we compress on the fly, default to fast compression.
  (compression 'gzip 3))

(define (default-compression type)
  (compression type 3))

(define (actual-compressions item requested)
  "Return the actual compressions used for ITEM, which may be %NO-COMPRESSION
if ITEM is already compressed."
  (if (compressed-file? item)
      (list %no-compression)
      requested))

(define %options
  (list (option '(#\h "help") #f #f
                (lambda _
                  (show-help)
                  (exit 0)))
        (option '(#\V "version") #f #f
                (lambda _
                  (show-version-and-exit "guix publish")))
        (option '(#\u "user") #t #f
                (lambda (opt name arg result)
                  (alist-cons 'user arg result)))
        (option '(#\p "port") #t #f
                (lambda (opt name arg result)
                  (alist-cons 'port (string->number* arg) result)))
        (option '("listen") #t #f
                (lambda (opt name arg result)
                  (match (getaddrinfo* arg)
                    ((info _ ...)
                     (alist-cons 'address (addrinfo:addr info)
                                 result))
                    (()
                     (leave (G_ "lookup of host '~a' returned nothing")
                            name)))))
        (option '(#\C "compression") #f #t
                (lambda (opt name arg result)
                  (let* ((colon (string-index arg #\:))
                         (type  (cond
                                 (colon (string-take arg colon))
                                 ((string->number arg) "gzip")
                                 (else arg)))
                         (level (if colon
                                    (string->number*
                                     (string-drop arg (+ 1 colon)))
                                    (or (string->number arg) 3))))
                    (match level
                      (0
                       (alist-cons 'compression %no-compression result))
                      (level
                       (match (string->compression-type type)
                         ((? symbol? type)
                          (alist-cons 'compression
                                      (compression type level)
                                      result))
                         (_
                          (warning (G_ "~a: unsupported compression type~%")
                                   type)
                          result)))))))
        (option '(#\c "cache") #t #f
                (lambda (opt name arg result)
                  (alist-cons 'cache arg result)))
        (option '("workers") #t #f
                (lambda (opt name arg result)
                  (alist-cons 'workers (string->number* arg)
                              result)))
        (option '("ttl") #t #f
                (lambda (opt name arg result)
                  (let ((duration (string->duration arg)))
                    (unless duration
                      (leave (G_ "~a: invalid duration~%") arg))
                    (alist-cons 'narinfo-ttl (time-second duration)
                                result))))
        (option '("nar-path") #t #f
                (lambda (opt name arg result)
                  (alist-cons 'nar-path arg result)))
        (option '("public-key") #t #f
                (lambda (opt name arg result)
                  (alist-cons 'public-key-file arg result)))
        (option '("private-key" "secret-key") #t #f
                (lambda (opt name arg result)
                  (alist-cons 'private-key-file arg result)))
        (option '(#\r "repl") #f #t
                (lambda (opt name arg result)
                  ;; If port unspecified, use default Guile REPL port.
                  (let ((port (and arg (string->number* arg))))
                    (alist-cons 'repl (or port 37146) result))))))

(define %default-options
  `((port . 8080)

    ;; By default, serve nars under "/nar".
    (nar-path . "nar")

    (public-key-file . ,%public-key-file)
    (private-key-file . ,%private-key-file)

    ;; Default number of workers when caching is enabled.
    (workers . ,(current-processor-count))

    (address . ,(make-socket-address AF_INET INADDR_ANY 0))
    (repl . #f)))

;; The key pair used to sign narinfos.
(define %private-key
  (make-parameter #f))
(define %public-key
  (make-parameter #f))

(define %nix-cache-info
  `(("StoreDir" . ,%store-directory)
    ("WantMassQuery" . 0)
    ("Priority" . 100)))

(define (signed-string s)
  "Sign the hash of the string S with the daemon's key.  Return a canonical
sexp for the signature."
  (let* ((public-key (%public-key))
         (hash (bytevector->hash-data (sha256 (string->utf8 s))
                                      #:key-type (key-type public-key))))
    (signature-sexp hash (%private-key) public-key)))

(define base64-encode-string
  (compose base64-encode string->utf8))

(define* (store-item->recutils store-item
                               #:key
                               (nar-path "nar")
                               (compression %no-compression)
                               file-size)
  "Return the 'Compression' and 'URL' fields of the narinfo for STORE-ITEM,
with COMPRESSION, starting at NAR-PATH."
  (let ((url (encode-and-join-uri-path
              `(,@(split-and-decode-uri-path nar-path)
                ,@(match compression
                    (($ <compression> 'none)
                     '())
                    (($ <compression> type)
                     (list (symbol->string type))))
                ,(basename store-item)))))
    (format #f "URL: ~a~%Compression: ~a~%~@[FileSize: ~a~%~]"
            url (compression-type compression) file-size)))

(define* (narinfo-string store store-path key
                         #:key (compressions (list %no-compression))
                         (nar-path "nar") (file-sizes '()))
  "Generate a narinfo key/value string for STORE-PATH; an exception is raised
if STORE-PATH is invalid.  Produce a URL that corresponds to COMPRESSION.  The
narinfo is signed with KEY.  NAR-PATH specifies the prefix for nar URLs.

Optionally, FILE-SIZES is a list of compression/integer pairs, where the
integer is size in bytes of the compressed NAR; it informs the client of how
much needs to be downloaded."
  (let* ((path-info  (query-path-info store store-path))
         (compressions (actual-compressions store-path compressions))
         (hash       (bytevector->nix-base32-string
                      (path-info-hash path-info)))
         (size       (path-info-nar-size path-info))
         (file-sizes `((,%no-compression . ,size) ,@file-sizes))
         (references (string-join
                      (map basename (path-info-references path-info))
                      " "))
         (deriver    (path-info-deriver path-info))
         (base-info  (format #f
                             "\
StorePath: ~a
~{~a~}\
NarHash: sha256:~a
NarSize: ~d
References: ~a~%"
                             store-path
                             (map (lambda (compression)
                                    (let ((size (assoc-ref file-sizes
                                                           compression)))
                                      (store-item->recutils store-path
                                                            #:file-size size
                                                            #:nar-path nar-path
                                                            #:compression
                                                            compression)))
                                  compressions)
                             hash size references))
         ;; Do not render a "Deriver" or "System" line if we are rendering
         ;; info for a derivation.
         (info       (if (not deriver)
                         base-info
                         (catch 'system-error
                           (lambda ()
                             (let ((drv (read-derivation-from-file deriver)))
                               (format #f "~aSystem: ~a~%Deriver: ~a~%"
                                       base-info (derivation-system drv)
                                       (basename deriver))))
                           (lambda args
                             ;; DERIVER might be missing, but that's fine:
                             ;; it's only used for <substitutable> where it's
                             ;; optional.  'System' is currently unused.
                             (if (= ENOENT (system-error-errno args))
                                 base-info
                                 (apply throw args))))))
         (signature  (base64-encode-string
                      (canonical-sexp->string (signed-string info)))))
    (format #f "~aSignature: 1;~a;~a~%" info (gethostname) signature)))

(define* (not-found request
                    #:key (phrase "Resource not found")
                    ttl)
  "Render 404 response for REQUEST."
  (values (build-response #:code 404
                          #:headers (if ttl
                                        `((cache-control (max-age . ,ttl)))
                                        '()))
          (string-append phrase ": "
                         (uri-path (request-uri request)))))

(define (render-nix-cache-info)
  "Render server information."
  (values '((content-type . (text/plain)))
          (lambda (port)
            (for-each (match-lambda
                       ((key . value)
                        (format port "~a: ~a~%" key value)))
                      %nix-cache-info))))

(define* (render-narinfo store request hash
                         #:key ttl (compressions (list %no-compression))
                         (nar-path "nar"))
  "Render metadata for the store path corresponding to HASH.  If TTL is true,
advertise it as the maximum validity period (in seconds) via the
'Cache-Control' header.  This allows 'guix substitute' to cache it for an
appropriate duration.  NAR-PATH specifies the prefix for nar URLs."
  (let ((store-path (hash-part->path store hash)))
    (if (string-null? store-path)
        (not-found request #:phrase "")
        (values `((content-type . (application/x-nix-narinfo))
                  ,@(if ttl
                        `((cache-control (max-age . ,ttl)))
                        '()))
                (cut display
                  (narinfo-string store store-path (%private-key)
                                  #:nar-path nar-path
                                  #:compressions compressions)
                  <>)))))

(define* (nar-cache-file directory item
                             #:key (compression %no-compression))
  (string-append directory "/"
                 (symbol->string (compression-type compression))
                 "/" (basename item) ".nar"))

(define* (narinfo-cache-file directory item
                             #:key (compression %no-compression))
  (string-append directory "/"
                 (symbol->string (compression-type compression))
                 "/" (basename item)
                 ".narinfo"))

(define (hash-part-mapping-cache-file directory hash)
  (string-append directory "/hashes/" hash))

(define run-single-baker
  (let ((baking (make-weak-value-hash-table))
        (mutex  (make-mutex)))
    (lambda (item thunk)
      "Run THUNK, which is supposed to bake ITEM, but make sure only one
thread is baking ITEM at a given time."
      (define selected?
        (with-mutex mutex
          (and (not (hash-ref baking item))
               (begin
                 (hash-set! baking item (current-thread))
                 #t))))

      (when selected?
        (dynamic-wind
          (const #t)
          thunk
          (lambda ()
            (with-mutex mutex
              (hash-remove! baking item))))))))

(define-syntax-rule (single-baker item exp ...)
  "Bake ITEM by evaluating EXP, but make sure there's only one baker for ITEM
at a time."
  (run-single-baker item (lambda () exp ...)))


(define (narinfo-files cache)
  "Return the list of .narinfo files under CACHE."
  (if (file-is-directory? cache)
      (find-files cache
                  (lambda (file stat)
                    (string-suffix? ".narinfo" file)))
      '()))

(define (nar-expiration-time ttl)
  "Return the narinfo expiration time (in seconds since the Epoch).  The
expiration time is +inf.0 when passed an item that is still in the store; in
other cases, it is the last-access time of the item plus TTL.

This policy allows us to keep cached nars that correspond to valid store
items.  Failing that, we could eventually have to recompute them and return
404 in the meantime."
  (let ((expiration-time (file-expiration-time ttl)))
    (lambda (file)
      (let ((item (string-append (%store-prefix) "/"
                                 (basename file ".narinfo"))))
        ;; Note: We don't need to use 'valid-path?' here because FILE would
        ;; not exist if ITEM were not valid in the first place.
        (if (file-exists? item)
            +inf.0
            (expiration-time file))))))

(define (hash-part->path* store hash cache)
  "Like 'hash-part->path' but cached results under CACHE.  This ensures we can
still map HASH to the corresponding store file name, even if said store item
vanished from the store in the meantime."
  (let ((cached (hash-part-mapping-cache-file cache hash)))
    (catch 'system-error
      (lambda ()
        (call-with-input-file cached read-string))
      (lambda args
        (if (= ENOENT (system-error-errno args))
            (match (hash-part->path store hash)
              ("" "")
              (result
               (mkdir-p (dirname cached))
               (call-with-output-file (string-append cached ".tmp")
                 (lambda (port)
                   (display result port)))
               (rename-file (string-append cached ".tmp") cached)
               result))
            (apply throw args))))))

(define* (render-narinfo/cached store request hash
                                #:key ttl (compressions (list %no-compression))
                                (nar-path "nar")
                                cache pool)
  "Respond to the narinfo request for REQUEST.  If the narinfo is available in
CACHE, then send it; otherwise, return 404 and \"bake\" that nar and narinfo
requested using POOL."
  (define (delete-entry narinfo)
    ;; Delete NARINFO and the corresponding nar from CACHE.
    (let* ((nar     (string-append (string-drop-right narinfo
                                                      (string-length ".narinfo"))
                                   ".nar"))
           (base    (basename narinfo ".narinfo"))
           (hash    (string-take base (string-index base #\-)))
           (mapping (hash-part-mapping-cache-file cache hash)))
      (delete-file* narinfo)
      (delete-file* nar)
      (delete-file* mapping)))

  (let* ((item         (hash-part->path* store hash cache))
         (compressions (actual-compressions item compressions))
         (cached       (and (not (string-null? item))
                            (narinfo-cache-file cache item
                                                #:compression
                                                (first compressions)))))
    (cond ((string-null? item)
           (not-found request))
          ((file-exists? cached)
           ;; Narinfo is in cache, send it.
           (values `((content-type . (application/x-nix-narinfo))
                     ,@(if ttl
                           `((cache-control (max-age . ,ttl)))
                           '()))
                   (lambda (port)
                     (display (call-with-input-file cached
                                read-string)
                              port))))
          ((and (file-exists? item)        ;cheaper than the 'valid-path?' RPC
                (valid-path? store item))
           ;; Nothing in cache: bake the narinfo and nar in the background and
           ;; return 404.
           (eventually pool
             (single-baker item
               ;; Check whether CACHED has been produced in the meantime.
               (unless (file-exists? cached)
                 ;; (format #t "baking ~s~%" item)
                 (bake-narinfo+nar cache item
                                   #:ttl ttl
                                   #:compressions compressions
                                   #:nar-path nar-path)))

             (when ttl
               (single-baker 'cache-cleanup
                 (maybe-remove-expired-cache-entries cache
                                                     narinfo-files
                                                     #:entry-expiration
                                                     (nar-expiration-time ttl)
                                                     #:delete-entry delete-entry
                                                     #:cleanup-period ttl))))
           (not-found request
                      #:phrase "We're baking it"
                      #:ttl 300))              ;should be available within 5m
          (else
           (not-found request #:phrase "")))))

(define (compress-nar cache item compression)
  "Save in directory CACHE the nar for ITEM compressed with COMPRESSION."
  (define nar
    (nar-cache-file cache item #:compression compression))

  (mkdir-p (dirname nar))
  (match (compression-type compression)
    ('gzip
     ;; Note: the file port gets closed along with the gzip port.
     (call-with-gzip-output-port (open-output-file (string-append nar ".tmp"))
       (lambda (port)
         (write-file item port))
       #:level (compression-level compression)
       #:buffer-size (* 128 1024))
     (rename-file (string-append nar ".tmp") nar))
    ('lzip
     ;; Note: the file port gets closed along with the lzip port.
     (call-with-lzip-output-port (open-output-file (string-append nar ".tmp"))
       (lambda (port)
         (write-file item port))
       #:level (compression-level compression))
     (rename-file (string-append nar ".tmp") nar))
    ('none
     ;; Cache nars even when compression is disabled so that we can
     ;; guarantee the TTL (see <https://bugs.gnu.org/28664>.)
     (with-atomic-file-output nar
       (lambda (port)
         (write-file item port))))))

(define* (bake-narinfo+nar cache item
                           #:key ttl (compressions (list %no-compression))
                           (nar-path "/nar"))
  "Write the narinfo and nar for ITEM to CACHE."
  (define (compressed-nar-size compression)
    (let* ((nar  (nar-cache-file cache item #:compression compression))
           (stat (stat nar #f)))
      (and stat
           (cons compression (stat:size stat)))))

  (let ((compression (actual-compressions item compressions)))

    (for-each (cut compress-nar cache item <>) compressions)

    (match compressions
      ((main others ...)
       (let ((narinfo (narinfo-cache-file cache item
                                          #:compression main)))
         (with-atomic-file-output narinfo
           (lambda (port)
             ;; Open a new connection to the store.  We cannot reuse the main
             ;; thread's connection to the store since we would end up sending
             ;; stuff concurrently on the same channel.
             (with-store store
               (let ((sizes (filter-map compressed-nar-size compression)))
                 (display (narinfo-string store item
                                          (%private-key)
                                          #:nar-path nar-path
                                          #:compressions compressions
                                          #:file-sizes sizes)
                          port)))))

         ;; Make narinfo files for OTHERS hard links to NARINFO such that the
         ;; atime-based cache eviction considers either all the nars or none
         ;; of them as candidates.
         (for-each (lambda (other)
                     (let ((other (narinfo-cache-file cache item
                                                      #:compression other)))
                       (link narinfo other)))
                   others))))))

;; XXX: Declare the 'X-Nar-Compression' HTTP header, which is in fact for
;; internal consumption: it allows us to pass the compression info to
;; 'http-write', as part of the workaround to <http://bugs.gnu.org/21093>.
(declare-header! "X-Nar-Compression"
                 (lambda (str)
                   (match (call-with-input-string str read)
                     (('compression type level)
                      (compression type level))))
                 compression?
                 (lambda (compression port)
                   (match compression
                     (($ <compression> type level)
                      (write `(compression ,type ,level) port)))))

(define* (render-nar store request store-item
                     #:key (compression %no-compression))
  "Render archive of the store path corresponding to STORE-ITEM."
  (let ((store-path (string-append %store-directory "/" store-item)))
    ;; The ISO-8859-1 charset *must* be used otherwise HTTP clients will
    ;; interpret the byte stream as UTF-8 and arbitrarily change invalid byte
    ;; sequences.
    (if (valid-path? store store-path)
        (values `((content-type . (application/x-nix-archive
                                   (charset . "ISO-8859-1")))
                  (x-nar-compression . ,compression))
                ;; XXX: We're not returning the actual contents, deferring
                ;; instead to 'http-write'.  This is a hack to work around
                ;; <http://bugs.gnu.org/21093>.
                store-path)
        (not-found request))))

(define* (render-nar/cached store cache request store-item
                            #:key ttl (compression %no-compression))
  "Respond to REQUEST with a nar for STORE-ITEM.  If the nar is in CACHE,
return it; otherwise, return 404.  When TTL is true, use it as the
'Cache-Control' expiration time."
  (let ((cached (nar-cache-file cache store-item
                                #:compression compression)))
    (if (file-exists? cached)
        (values `((content-type . (application/octet-stream
                                   (charset . "ISO-8859-1")))
                  ,@(if ttl
                        `((cache-control (max-age . ,ttl)))
                        '())

                  ;; XXX: We're not returning the actual contents, deferring
                  ;; instead to 'http-write'.  This is a hack to work around
                  ;; <http://bugs.gnu.org/21093>.
                  (x-raw-file . ,cached))
                #f)
        (not-found request))))

(define (render-content-addressed-file store request
                                       name algo hash)
  "Return the content of the result of the fixed-output derivation NAME that
has the given HASH of type ALGO."
  ;; TODO: Support other hash algorithms.
  (if (and (eq? algo 'sha256) (= 32 (bytevector-length hash)))
      (let ((item (fixed-output-path name hash
                                     #:hash-algo algo
                                     #:recursive? #f)))
        (if (valid-path? store item)
            (values `((content-type . (application/octet-stream
                                       (charset . "ISO-8859-1")))
                      ;; XXX: We're not returning the actual contents,
                      ;; deferring instead to 'http-write'.  This is a hack to
                      ;; work around <http://bugs.gnu.org/21093>.
                      (x-raw-file . ,item))
                    #f)
            (not-found request)))
      (not-found request)))

(define (render-log-file store request name)
  "Render the log file for NAME, the base name of a store item.  Don't attempt
to compress or decompress the log file; just return it as-is."
  (define (response-headers file)
    ;; XXX: We're not returning the actual contents, deferring instead to
    ;; 'http-write'.  This is a hack to work around
    ;; <http://bugs.gnu.org/21093>.
    (cond ((string-suffix? ".gz" file)
           `((content-type . (text/plain (charset . "UTF-8")))
             (content-encoding . (gzip))
             (x-raw-file . ,file)))
          ((string-suffix? ".bz2" file)
           `((content-type . (application/x-bzip2
                              (charset . "ISO-8859-1")))
             (x-raw-file . ,file)))
          (else                                   ;uncompressed
           `((content-type . (text/plain (charset . "UTF-8")))
             (x-raw-file . ,file)))))

  (let ((log (log-file store
                       (string-append (%store-prefix) "/" name))))
    (if log
        (values (response-headers log) log)
        (not-found request))))

(define (render-home-page request)
  "Render the home page."
  (values `((content-type . (text/html (charset . "UTF-8"))))
          (call-with-output-string
            (lambda (port)
              (sxml->xml '(html
                           (head (title "GNU Guix Substitute Server"))
                           (body
                            (h1 "GNU Guix Substitute Server")
                            (p "Hi, "
                               (a (@ (href
                                      "https://guix.gnu.org/manual/en/html_node/Invoking-guix-publish.html"))
                                  (tt "guix publish"))
                               " speaking.  Welcome!")))
                         port)))))

(define (extract-narinfo-hash str)
  "Return the hash within the narinfo resource string STR, or false if STR
is invalid."
  (and (string-suffix? ".narinfo" str)
       (let ((base (string-drop-right str 8)))
         (and (string-every %nix-base32-charset base)
              base))))

(define (get-request? request)
  "Return #t if REQUEST uses the GET method."
  (eq? (request-method request) 'GET))

(define (request-path-components request)
  "Split the URI path of REQUEST into a list of component strings.  For
example: \"/foo/bar\" yields '(\"foo\" \"bar\")."
  (split-and-decode-uri-path (uri-path (request-uri request))))

\f
;;;
;;; Server.
;;;

(define %http-write
  (@@ (web server http) http-write))

(match (list (major-version) (minor-version) (micro-version))
  (("2" "2" "5")                                  ;Guile 2.2.5
   (let ()
     (define %read-line (@ (ice-9 rdelim) %read-line))
     (define bad-header (@@ (web http) bad-header))

     ;; XXX: Work around <https://bugs.gnu.org/36350> by reverting to the
     ;; definition of 'read-header-line' as found in 2.2.4 and earlier.
     (define (read-header-line port)
       "Read an HTTP header line and return it without its final CRLF or LF.
Raise a 'bad-header' exception if the line does not end in CRLF or LF,
or if EOF is reached."
       (match (%read-line port)
         (((? string? line) . #\newline)
          ;; '%read-line' does not consider #\return a delimiter; so if it's
          ;; there, remove it.  We are more tolerant than the RFC in that we
          ;; tolerate LF-only endings.
          (if (string-suffix? "\r" line)
              (string-drop-right line 1)
              line))
         ((line . _)                              ;EOF or missing delimiter
          (bad-header 'read-header-line line))))

     (set! (@@ (web http) read-header-line) read-header-line)))
  (_ #t))

(define (strip-headers response)
  "Return RESPONSE's headers minus 'Content-Length' and our internal headers."
  (fold alist-delete
        (response-headers response)
        '(content-length x-raw-file x-nar-compression)))

(define (sans-content-length response)
  "Return RESPONSE without its 'content-length' header."
  (set-field response (response-headers)
             (strip-headers response)))

(define (with-content-length response length)
  "Return RESPONSE with a 'content-length' header set to LENGTH."
  (set-field response (response-headers)
             (alist-cons 'content-length length
                         (strip-headers response))))

(define-syntax-rule (swallow-EPIPE exp ...)
  "Swallow EPIPE errors raised by EXP..."
  (catch 'system-error
    (lambda ()
      exp ...)
    (lambda args
      (if (= EPIPE (system-error-errno args))
          (values)
          (apply throw args)))))

(define-syntax-rule (swallow-zlib-error exp ...)
  "Swallow 'zlib-error' exceptions raised by EXP..."
  (catch 'zlib-error
    (lambda ()
      exp ...)
    (const #f)))

(define (nar-response-port response compression)
  "Return a port on which to write the body of RESPONSE, the response of a
/nar request, according to COMPRESSION."
  (match compression
    (($ <compression> 'gzip level)
     ;; Note: We cannot used chunked encoding here because
     ;; 'make-gzip-output-port' wants a file port.
     (make-gzip-output-port (response-port response)
                            #:level level
                            #:buffer-size (* 64 1024)))
    (($ <compression> 'lzip level)
     (make-lzip-output-port (response-port response)
                            #:level level))
    (($ <compression> 'none)
     (response-port response))
    (#f
     (response-port response))))

(define (http-write server client response body)
  "Write RESPONSE and BODY to CLIENT, possibly in a separate thread to avoid
blocking."
  (match (response-content-type response)
    (('application/x-nix-archive . _)
     ;; Sending the the whole archive can take time so do it in a separate
     ;; thread so that the main thread can keep working in the meantime.
     (call-with-new-thread
      (lambda ()
        (set-thread-name "publish nar")
        (let* ((compression (assoc-ref (response-headers response)
                                       'x-nar-compression))
               (response    (write-response (sans-content-length response)
                                            client))
               (port        (begin
                              (force-output client)
                              (nar-response-port response compression))))
          ;; XXX: Given our ugly workaround for <http://bugs.gnu.org/21093> in
          ;; 'render-nar', BODY here is just the file name of the store item.
          ;; We call 'write-file' from here because we know that's the only
          ;; way to avoid building the whole nar in memory, which could
          ;; quickly become a real problem.  As a bonus, we even do
          ;; sendfile(2) directly from the store files to the socket.
          (swallow-zlib-error
           (swallow-EPIPE
            (write-file (utf8->string body) port)))
          (swallow-zlib-error
           (close-port port))
          (values)))))
    (_
     (match (assoc-ref (response-headers response) 'x-raw-file)
       ((? string? file)
        ;; Send a raw file in a separate thread.
        (call-with-new-thread
         (lambda ()
           (set-thread-name "publish file")
           (catch 'system-error
             (lambda ()
               (call-with-input-file file
                 (lambda (input)
                   (let* ((size     (stat:size (stat input)))
                          (response (write-response (with-content-length response
                                                                         size)
                                                    client))
                          (output   (response-port response)))
                     (setsockopt client SOL_SOCKET SO_SNDBUF (* 128 1024))
                     (if (file-port? output)
                         (sendfile output input size)
                         (dump-port input output))
                     (close-port output)
                     (values)))))
             (lambda args
               ;; If the file was GC'd behind our back, that's fine.  Likewise if
               ;; the client closes the connection.
               (unless (memv (system-error-errno args)
                             (list ENOENT EPIPE ECONNRESET))
                 (apply throw args))
               (values))))))
       (#f
        ;; Handle other responses sequentially.
        (%http-write server client response body))))))

(define-server-impl concurrent-http-server
  ;; A variant of Guile's built-in HTTP server that offloads possibly long
  ;; responses to a different thread.
  (@@ (web server http) http-open)
  (@@ (web server http) http-read)
  http-write
  (@@ (web server http) http-close))

(define (string->compression-type string)
  "Return a symbol denoting the compression method expressed by STRING; return
#f if STRING doesn't match any supported method."
  (match string
    ("gzip" 'gzip)
    ("lzip" 'lzip)
    (_      #f)))

(define (effective-compression requested-type compressions)
  "Given the REQUESTED-TYPE for compression and the set of chosen COMPRESSION
methods, return the applicable compression."
  (or (find (match-lambda
              (($ <compression> type)
               (and (eq? type requested-type)
                    compression)))
            compressions)
      (default-compression requested-type)))

(define* (make-request-handler store
                               #:key
                               cache pool
                               narinfo-ttl
                               (nar-path "nar")
                               (compressions (list %no-compression)))
  (define compression-type?
    string->compression-type)

  (define nar-path?
    (let ((expected (split-and-decode-uri-path nar-path)))
      (cut equal? expected <>)))

  (lambda (request body)
    (format #t "~a ~a~%"
            (request-method request)
            (uri-path (request-uri request)))
    (if (get-request? request)                    ;reject POST, PUT, etc.
        (match (request-path-components request)
          ;; /nix-cache-info
          (("nix-cache-info")
           (render-nix-cache-info))
          ;; /
          ((or () ("index.html"))
           (render-home-page request))
          ;; /<hash>.narinfo
          (((= extract-narinfo-hash (? string? hash)))
           (if cache
               (render-narinfo/cached store request hash
                                      #:cache cache
                                      #:pool pool
                                      #:ttl narinfo-ttl
                                      #:nar-path nar-path
                                      #:compressions compressions)
               (render-narinfo store request hash
                               #:ttl narinfo-ttl
                               #:nar-path nar-path
                               #:compressions compressions)))
          ;; /nar/file/NAME/sha256/HASH
          (("file" name "sha256" hash)
           (guard (c ((invalid-base32-character? c)
                      (not-found request)))
             (let ((hash (nix-base32-string->bytevector hash)))
               (render-content-addressed-file store request
                                              name 'sha256 hash))))

          ;; /log/OUTPUT
          (("log" name)
           (render-log-file store request name))

          ;; Use different URLs depending on the compression type.  This
          ;; guarantees that /nar URLs remain valid even when 'guix publish'
          ;; is restarted with different compression parameters.

          ;; /nar/gzip/<store-item>
          ((components ... (? compression-type? type) store-item)
           (if (nar-path? components)
               (let* ((compression-type (string->compression-type type))
                      (compression (effective-compression compression-type
                                                          compressions)))
                 (if cache
                     (render-nar/cached store cache request store-item
                                        #:ttl narinfo-ttl
                                        #:compression compression)
                     (render-nar store request store-item
                                 #:compression compression)))
               (not-found request)))

          ;; /nar/<store-item>
          ((components ... store-item)
           (if (nar-path? components)
               (if cache
                   (render-nar/cached store cache request store-item
                                      #:ttl narinfo-ttl
                                      #:compression %no-compression)
                   (render-nar store request store-item
                               #:compression %no-compression))
               (not-found request)))

          (x (not-found request)))
        (not-found request))))

(define* (run-publish-server socket store
                             #:key
                             (compressions (list %no-compression))
                             (nar-path "nar") narinfo-ttl
                             cache pool)
  (run-server (make-request-handler store
                                    #:cache cache
                                    #:pool pool
                                    #:nar-path nar-path
                                    #:narinfo-ttl narinfo-ttl
                                    #:compressions compressions)
              concurrent-http-server
              `(#:socket ,socket)))

(define (open-server-socket address)
  "Return a TCP socket bound to ADDRESS, a socket address."
  (let ((sock (socket (sockaddr:fam address) SOCK_STREAM 0)))
    (setsockopt sock SOL_SOCKET SO_REUSEADDR 1)
    (bind sock address)
    sock))

(define (gather-user-privileges user)
  "Switch to the identity of USER, a user name."
  (catch 'misc-error
    (lambda ()
      (let ((user (getpw user)))
        (setgroups #())
        (setgid (passwd:gid user))
        (setuid (passwd:uid user))))
    (lambda (key proc message args . rest)
      (leave (G_ "user '~a' not found: ~a~%")
             user (apply format #f message args)))))

\f
;;;
;;; Entry point.
;;;

(define-command (guix-publish . args)
  (category advanced)
  (synopsis "publish build results over HTTP")

  (with-error-handling
    (let* ((opts    (args-fold* args %options
                                (lambda (opt name arg result)
                                  (leave (G_ "~A: unrecognized option~%") name))
                                (lambda (arg result)
                                  (leave (G_ "~A: extraneous argument~%") arg))
                                %default-options))
           (user    (assoc-ref opts 'user))
           (port    (assoc-ref opts 'port))
           (ttl     (assoc-ref opts 'narinfo-ttl))
           (compressions (match (filter-map (match-lambda
                                              (('compression . compression)
                                               compression)
                                              (_ #f))
                                            opts)
                           (()
                            ;; Default to fast & low compression.
                            (list %default-gzip-compression))
                           (lst (reverse lst))))
           (address (let ((addr (assoc-ref opts 'address)))
                      (make-socket-address (sockaddr:fam addr)
                                           (sockaddr:addr addr)
                                           port)))
           (socket  (open-server-socket address))
           (nar-path  (assoc-ref opts 'nar-path))
           (repl-port (assoc-ref opts 'repl))
           (cache     (assoc-ref opts 'cache))
           (workers   (assoc-ref opts 'workers))

           ;; Read the key right away so that (1) we fail early on if we can't
           ;; access them, and (2) we can then drop privileges.
           (public-key  (read-file-sexp (assoc-ref opts 'public-key-file)))
           (private-key (read-file-sexp (assoc-ref opts 'private-key-file))))

      (when user
        ;; Now that we've read the key material and opened the socket, we can
        ;; drop privileges.
        (gather-user-privileges user))

      (when (zero? (getuid))
        (warning (G_ "server running as root; \
consider using the '--user' option!~%")))

      (parameterize ((%public-key public-key)
                     (%private-key private-key))
        (info (G_ "publishing ~a on ~a, port ~d~%")
              %store-directory
              (inet-ntop (sockaddr:fam address) (sockaddr:addr address))
              (sockaddr:port address))

        (for-each (lambda (compression)
                    (info (G_ "using '~a' compression method, level ~a~%")
                          (compression-type compression)
                          (compression-level compression)))
                  compressions)

        (when repl-port
          (repl:spawn-server (repl:make-tcp-server-socket #:port repl-port)))

        ;; Set the name of the main thread.
        (set-thread-name "guix publish")

        (with-store store
          (run-publish-server socket store
                              #:cache cache
                              #:pool (and cache (make-pool workers
                                                           #:thread-name
                                                           "publish worker"))
                              #:nar-path nar-path
                              #:compressions compressions
                              #:narinfo-ttl ttl))))))

;;; Local Variables:
;;; eval: (put 'single-baker 'scheme-indent-function 1)
;;; End:

debug log:

solving 872931840a ...
found 872931840a in https://yhetil.org/guix-patches/20200901204136.21375-1-ludo@gnu.org/
found 61542f83a0 in https://git.savannah.gnu.org/cgit/guix.git
preparing index
index prepared:
100644 61542f83a084432a23158c73dda7ae90dbddde2f	guix/scripts/publish.scm

applying [1/1] https://yhetil.org/guix-patches/20200901204136.21375-1-ludo@gnu.org/
diff --git a/guix/scripts/publish.scm b/guix/scripts/publish.scm
index 61542f83a0..872931840a 100644

Checking patch guix/scripts/publish.scm...
Applied patch guix/scripts/publish.scm cleanly.

index at:
100644 872931840aa96806b815af7953b9241f13036d77	guix/scripts/publish.scm

(*) Git path names are given by the tree(s) the blob belongs to.
    Blobs themselves have no identifier aside from the hash of its contents.^

Code repositories for project(s) associated with this public inbox

	https://git.savannah.gnu.org/cgit/guix.git

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).