all messages for Guix-related lists mirrored at yhetil.org
 help / color / mirror / code / Atom feed
blob 48309f9b3a49a059c06678c4d7d9560aca96ef91 31011 bytes (raw)
name: guix/scripts/substitute.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
 
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2014 Nikita Karetnikov <nikita@karetnikov.org>
;;; Copyright © 2018 Kyle Meyer <kyle@kyleam.com>
;;; Copyright © 2020 Christopher Baines <mail@cbaines.net>
;;;
;;; 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 substitute)
  #:use-module (guix ui)
  #:use-module (guix scripts)
  #:use-module (guix narinfo)
  #:use-module (guix store)
  #:use-module (guix substitutes)
  #:use-module (guix utils)
  #:use-module (guix combinators)
  #:use-module (guix config)
  #:use-module (guix records)
  #:use-module (guix diagnostics)
  #:use-module (guix i18n)
  #:use-module ((guix serialization) #:select (restore-file dump-file))
  #:autoload   (guix store deduplication) (dump-file/deduplicate)
  #:autoload   (guix scripts discover) (read-substitute-urls)
  #:use-module (gcrypt hash)
  #:use-module (guix base32)
  #:use-module (guix base64)
  #:use-module (guix cache)
  #:use-module (gcrypt pk-crypto)
  #:use-module (guix pki)
  #:use-module ((guix build utils) #:select (mkdir-p))
  #:use-module ((guix build download)
                #:select (uri-abbreviation nar-uri-abbreviation
                          (open-connection-for-uri
                           . guix:open-connection-for-uri)))
  #:autoload   (gnutls) (error/invalid-session)
  #:use-module (guix progress)
  #:use-module ((guix build syscalls)
                #:select (set-thread-name))
  #:use-module (ice-9 rdelim)
  #:use-module (ice-9 match)
  #:use-module (ice-9 format)
  #:use-module (ice-9 ftw)
  #:use-module (rnrs bytevectors)
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-11)
  #:use-module (srfi srfi-19)
  #:use-module (srfi srfi-26)
  #:use-module (srfi srfi-34)
  #:use-module (srfi srfi-35)
  #:use-module (web uri)
  #:use-module (guix http-client)
  #:export (%allow-unauthenticated-substitutes?
            %reply-file-descriptor

            substitute-urls
            guix-substitute))

;;; Comment:
;;;
;;; This is the "binary substituter".  It is invoked by the daemon do check
;;; for the existence of available "substitutes" (pre-built binaries), and to
;;; actually use them as a substitute to building things locally.
;;;
;;; If possible, substitute a binary for the requested store path, using a Nix
;;; "binary cache".  This program implements the Nix "substituter" protocol.
;;;
;;; Code:

(define %narinfo-expired-cache-entry-removal-delay
  ;; How often we want to remove files corresponding to expired cache entries.
  (* 7 24 3600))

(define (warn-about-missing-authentication)
  (warning (G_ "authentication and authorization of substitutes \
disabled!~%"))
  #t)

(define %allow-unauthenticated-substitutes?
  ;; Whether to allow unchecked substitutes.  This is useful for testing
  ;; purposes, and should be avoided otherwise.
  (make-parameter
   (and=> (getenv "GUIX_ALLOW_UNAUTHENTICATED_SUBSTITUTES")
          (cut string-ci=? <> "yes"))))

(define %fetch-timeout
  ;; Number of seconds after which networking is considered "slow".
  5)

(define %random-state
  (seed->random-state (+ (ash (cdr (gettimeofday)) 32) (getpid))))

(define-syntax-rule (with-timeout duration handler body ...)
  "Run BODY; when DURATION seconds have expired, call HANDLER, and run BODY
again."
  (begin
    (sigaction SIGALRM
      (lambda (signum)
        (sigaction SIGALRM SIG_DFL)
        handler))
    (alarm duration)
    (call-with-values
        (lambda ()
          (let try ()
            (catch 'system-error
              (lambda ()
                body ...)
              (lambda args
                ;; Before Guile v2.0.9-39-gfe51c7b, the SIGALRM triggers EINTR
                ;; because of the bug at
                ;; <http://lists.gnu.org/archive/html/guile-devel/2013-06/msg00050.html>.
                ;; When that happens, try again.  Note: SA_RESTART cannot be
                ;; used because of <http://bugs.gnu.org/14640>.
                (if (= EINTR (system-error-errno args))
                    (begin
                      ;; Wait a little to avoid bursts.
                      (usleep (random 3000000 %random-state))
                      (try))
                    (apply throw args))))))
      (lambda result
        (alarm 0)
        (sigaction SIGALRM SIG_DFL)
        (apply values result)))))

(define (at-most max-length lst)
  "If LST is shorter than MAX-LENGTH, return it and the empty list; otherwise
return its MAX-LENGTH first elements and its tail."
  (let loop ((len 0)
             (lst lst)
             (result '()))
    (match lst
      (()
       (values (reverse result) '()))
      ((head . tail)
       (if (>= len max-length)
           (values (reverse result) lst)
           (loop (+ 1 len) tail (cons head result)))))))

(define (narinfo-from-file file url)
  "Attempt to read a narinfo from FILE, using URL as the cache URL.  Return #f
if file doesn't exist, and the narinfo otherwise."
  (catch 'system-error
    (lambda ()
      (call-with-input-file file
        (cut read-narinfo <> url)))
    (lambda args
      (if (= ENOENT (system-error-errno args))
          #f
          (apply throw args)))))

(define (lookup-narinfo caches path authorized?)
  "Return the narinfo for PATH in CACHES, or #f when no substitute for PATH
was found."
  (match (lookup-narinfos/diverse caches (list path) authorized?)
    ((answer) answer)
    (_        #f)))

(define (cached-narinfo-expiration-time file)
  "Return the expiration time for FILE, which is a cached narinfo."
  (catch 'system-error
    (lambda ()
      (call-with-input-file file
        (lambda (port)
          (match (read port)
            (('narinfo ('version 2) ('cache-uri uri)
                       ('date date) ('ttl ttl) ('value #f))
             (+ date ttl))
            (('narinfo ('version 2) ('cache-uri uri)
                       ('date date) ('ttl ttl) ('value value))
             (+ date ttl))
            (x
             0)))))
    (lambda args
      ;; FILE may have been deleted.
      0)))

(define (narinfo-cache-directories directory)
  "Return the list of narinfo cache directories (one per cache URL.)"
  (map (cut string-append directory "/" <>)
       (scandir %narinfo-cache-directory
                (lambda (item)
                  (and (not (member item '("." "..")))
                       (file-is-directory?
                        (string-append %narinfo-cache-directory
                                       "/" item)))))))

(define* (cached-narinfo-files #:optional
                               (directory %narinfo-cache-directory))
  "Return the list of cached narinfo files under DIRECTORY."
  (append-map (lambda (directory)
                (map (cut string-append directory "/" <>)
                     (scandir directory
                              (lambda (file)
                                (= (string-length file) 32)))))
              (narinfo-cache-directories directory)))

(define-syntax with-networking
  (syntax-rules ()
    "Catch DNS lookup errors and TLS errors and gracefully exit."
    ;; Note: no attempt is made to catch other networking errors, because DNS
    ;; lookup errors are typically the first one, and because other errors are
    ;; a subset of `system-error', which is harder to filter.
    ((_ exp ...)
     ;; Use a pre-unwind handler so that re-throwing preserves useful
     ;; backtraces.  'with-throw-handler' works for Guile 2.2 and 3.0.
     (with-throw-handler #t
       (lambda () exp ...)
       (match-lambda*
         (('getaddrinfo-error error)
          (leave (G_ "host name lookup error: ~a~%")
                 (gai-strerror error)))
         (('gnutls-error error proc . rest)
          (let ((error->string (module-ref (resolve-interface '(gnutls))
                                           'error->string)))
            (leave (G_ "TLS error in procedure '~a': ~a~%")
                   proc (error->string error))))
         (args
          (apply throw args)))))))

\f
;;;
;;; Help.
;;;

(define (show-help)
  (display (G_ "Usage: guix substitute [OPTION]...
Internal tool to substitute a pre-built binary to a local build.\n"))
  (display (G_ "
      --query            report on the availability of substitutes for the
                         store file names passed on the standard input"))
  (display (G_ "
      --substitute STORE-FILE DESTINATION
                         download STORE-FILE and store it as a Nar in file
                         DESTINATION"))
  (newline)
  (display (G_ "
  -h, --help             display this help and exit"))
  (display (G_ "
  -V, --version          display version information and exit"))
  (newline)
  (show-bug-report-information))


\f
;;;
;;; Daemon/substituter protocol.
;;;

(define %prefer-fast-decompression?
  ;; Whether to prefer fast decompression over good compression ratios.  This
  ;; serves in particular to choose between lzip (high compression ratio but
  ;; low decompression throughput) and zstd (lower compression ratio but high
  ;; decompression throughput).
  #f)

(define (call-with-cpu-usage-monitoring proc)
  (let ((before (times)))
    (proc)
    (let ((after (times)))
      (if (= (tms:clock after) (tms:clock before))
          0
          (/ (- (tms:utime after) (tms:utime before))
             (- (tms:clock after) (tms:clock before))
             1.)))))

(define-syntax-rule (with-cpu-usage-monitoring exp ...)
  "Evaluate EXP...  Return its CPU usage as a fraction between 0 and 1."
  (call-with-cpu-usage-monitoring (lambda () exp ...)))

(define (display-narinfo-data port narinfo)
  "Write to PORT the contents of NARINFO in the format expected by the
daemon."
  (format port "~a\n~a\n~a\n"
          (narinfo-path narinfo)
          (or (and=> (narinfo-deriver narinfo)
                     (cute string-append (%store-prefix) "/" <>))
              "")
          (length (narinfo-references narinfo)))
  (for-each (cute format port "~a/~a~%" (%store-prefix) <>)
            (narinfo-references narinfo))

  (let-values (((uri compression file-size)
                (narinfo-best-uri narinfo
                                  #:fast-decompression?
                                  %prefer-fast-decompression?)))
    (format port "~a\n~a\n"
            (or file-size 0)
            (or (narinfo-size narinfo) 0))))

(define* (process-query port command
                        #:key cache-urls acl)
  "Reply on PORT to COMMAND, a query as written by the daemon to this process's
standard input.  Use ACL as the access-control list against which to check
authorized substitutes."
  (define valid?
    (if (%allow-unauthenticated-substitutes?)
        (begin
          (warn-about-missing-authentication)

          (const #t))
        (lambda (obj)
          (valid-narinfo? obj acl))))

  (define* (make-progress-reporter total #:key url)
    (define done 0)

    (define (report-progress)
      (erase-current-line (current-error-port)) ;erase current line
      (force-output (current-error-port))
      (format (current-error-port)
              (G_ "updating substitutes from '~a'... ~5,1f%")
              url (* 100. (/ done total)))
      (set! done (+ 1 done)))

    (progress-reporter
     (start report-progress)
     (report report-progress)
     (stop (lambda ()
             (newline (current-error-port))))))

  (match (string-tokenize command)
    (("have" paths ..1)
     ;; Return the subset of PATHS available in CACHE-URLS.
     (let ((substitutable (lookup-narinfos/diverse
                           cache-urls paths valid?
                           #:open-connection open-connection-for-uri/cached
                           #:make-progress-reporter make-progress-reporter)))
       (for-each (lambda (narinfo)
                   (format port "~a~%" (narinfo-path narinfo)))
                 substitutable)
       (newline port)))
    (("info" paths ..1)
     ;; Reply info about PATHS if it's in CACHE-URLS.
     (let ((substitutable (lookup-narinfos/diverse
                           cache-urls paths valid?
                           #:open-connection open-connection-for-uri/cached
                           #:make-progress-reporter make-progress-reporter)))
       (for-each (cut display-narinfo-data port <>) substitutable)
       (newline port)))
    (wtf
     (error "unknown `--query' command" wtf))))

(define %max-cached-connections
  ;; Maximum number of connections kept in cache by
  ;; 'open-connection-for-uri/cached'.
  16)

(define open-connection-for-uri/cached
  (let ((cache '()))
    (lambda* (uri #:key fresh? (timeout %fetch-timeout) verify-certificate?)
      "Return a connection for URI, possibly reusing a cached connection.
When FRESH? is true, delete any cached connections for URI and open a new one.
Return #f if URI's scheme is 'file' or #f.

When true, TIMEOUT is the maximum number of milliseconds to wait for
connection establishment.  When VERIFY-CERTIFICATE? is true, verify HTTPS
server certificates."
      (define host (uri-host uri))
      (define scheme (uri-scheme uri))
      (define key (list host scheme (uri-port uri)))

      (and (not (memq scheme '(file #f)))
           (match (assoc-ref cache key)
             (#f
              ;; Open a new connection to URI and evict old entries from
              ;; CACHE, if any.
              (let-values (((socket)
                            (guix:open-connection-for-uri
                             uri
                             #:verify-certificate? verify-certificate?
                             #:timeout timeout))
                           ((new-cache evicted)
                            (at-most (- %max-cached-connections 1) cache)))
                (for-each (match-lambda
                            ((_ . port)
                             (false-if-exception (close-port port))))
                          evicted)
                (set! cache (alist-cons key socket new-cache))
                socket))
             (socket
              (if (or fresh? (port-closed? socket))
                  (begin
                    (false-if-exception (close-port socket))
                    (set! cache (alist-delete key cache))
                    (open-connection-for-uri/cached uri #:timeout timeout
                                                    #:verify-certificate?
                                                    verify-certificate?))
                  (begin
                    ;; Drain input left from the previous use.
                    (drain-input socket)
                    socket))))))))

(define (call-with-cached-connection uri proc)
  (let ((port (open-connection-for-uri/cached uri
                                              #:verify-certificate? #f)))
    (catch #t
      (lambda ()
        (proc port))
      (lambda (key . args)
        ;; If PORT was cached and the server closed the connection in the
        ;; meantime, we get EPIPE.  In that case, open a fresh connection
        ;; and retry.  We might also get 'bad-response or a similar
        ;; exception from (web response) later on, once we've sent the
        ;; request, or a ERROR/INVALID-SESSION from GnuTLS.
        (if (or (and (eq? key 'system-error)
                     (= EPIPE (system-error-errno `(,key ,@args))))
                (and (eq? key 'gnutls-error)
                     (eq? (first args) error/invalid-session))
                (memq key '(bad-response bad-header bad-header-component)))
            (proc (open-connection-for-uri/cached uri
                                                  #:verify-certificate? #f
                                                  #:fresh? #t))
            (apply throw key args))))))

(define-syntax-rule (with-cached-connection uri port exp ...)
  "Bind PORT with EXP... to a socket connected to URI."
  (call-with-cached-connection uri (lambda (port) exp ...)))

(define* (process-substitution port store-item destination
                               #:key cache-urls acl
                               deduplicate? print-build-trace?)
  "Substitute STORE-ITEM (a store file name) from CACHE-URLS, and write it to
DESTINATION as a nar file.  Verify the substitute against ACL, and verify its
hash against what appears in the narinfo.  When DEDUPLICATE? is true, and if
DESTINATION is in the store, deduplicate its files.  Print a status line to
PORT."
  (define narinfo
    (lookup-narinfo cache-urls store-item
                    (if (%allow-unauthenticated-substitutes?)
                        (const #t)
                        (cut valid-narinfo? <> acl))))

  (define destination-in-store?
    (string-prefix? (string-append (%store-prefix) "/")
                    destination))

  (define (dump-file/deduplicate* . args)
    ;; Make sure deduplication looks at the right store (necessary in test
    ;; environments).
    (apply dump-file/deduplicate
           (append args (list #:store (%store-prefix)))))

  (define (fetch uri)
    (case (uri-scheme uri)
      ((file)
       (let ((port (open-file (uri-path uri) "r0b")))
         (values port (stat:size (stat port)))))
      ((http https)
       (guard (c ((http-get-error? c)
                  (leave (G_ "download from '~a' failed: ~a, ~s~%")
                         (uri->string (http-get-error-uri c))
                         (http-get-error-code c)
                         (http-get-error-reason c))))
         ;; Test this with:
         ;;   sudo tc qdisc add dev eth0 root netem delay 1500ms
         ;; and then cancel with:
         ;;   sudo tc qdisc del dev eth0 root
         (with-timeout %fetch-timeout
           (begin
             (warning (G_ "while fetching ~a: server is somewhat slow~%")
                      (uri->string uri))
             (warning (G_ "try `--no-substitutes' if the problem persists~%")))
           (with-cached-connection uri port
             (http-fetch uri #:text? #f
                         #:port port
                         #:keep-alive? #t
                         #:buffered? #f)))))
      (else
       (leave (G_ "unsupported substitute URI scheme: ~a~%")
              (uri->string uri)))))

  (unless narinfo
    (leave (G_ "no valid substitute for '~a'~%")
           store-item))

  (let-values (((uri compression file-size)
                (narinfo-best-uri narinfo
                                  #:fast-decompression?
                                  %prefer-fast-decompression?)))
    (unless print-build-trace?
      (format (current-error-port)
              (G_ "Downloading ~a...~%") (uri->string uri)))

    (let*-values (((raw download-size)
                   ;; 'guix publish' without '--cache' doesn't specify a
                   ;; Content-Length, so DOWNLOAD-SIZE is #f in this case.
                   (fetch uri))
                  ((progress)
                   (let* ((dl-size  (or download-size
                                        (and (equal? compression "none")
                                             (narinfo-size narinfo))))
                          (reporter (if print-build-trace?
                                        (progress-reporter/trace
                                         destination
                                         (uri->string uri) dl-size
                                         (current-error-port))
                                        (progress-reporter/file
                                         (uri->string uri) dl-size
                                         (current-error-port)
                                         #:abbreviation nar-uri-abbreviation))))
                     ;; Keep RAW open upon completion so we can later reuse
                     ;; the underlying connection.
                     (progress-report-port reporter raw #:close? #f)))
                  ((input pids)
                   ;; NOTE: This 'progress' port of current process will be
                   ;; closed here, while the child process doing the
                   ;; reporting will close it upon exit.
                   (decompressed-port (string->symbol compression)
                                      progress))

                  ;; Compute the actual nar hash as we read it.
                  ((algorithm expected)
                   (narinfo-hash-algorithm+value narinfo))
                  ((hashed get-hash)
                   (open-hash-input-port algorithm input)))
      ;; Unpack the Nar at INPUT into DESTINATION.
      (define cpu-usage
        (with-cpu-usage-monitoring
         (restore-file hashed destination
                       #:dump-file (if (and destination-in-store?
                                            deduplicate?)
                                       dump-file/deduplicate*
                                       dump-file))))

      ;; Create a hysteresis: depending on CPU usage, favor compression
      ;; methods with faster decompression (like ztsd) or methods with better
      ;; compression ratios (like lzip).  This stems from the observation that
      ;; substitution can be CPU-bound when high-speed networks are used:
      ;; <https://lists.gnu.org/archive/html/guix-devel/2020-12/msg00177.html>.
      ;; To simulate "slow" networking or changing conditions, run:
      ;;   sudo tc qdisc add dev eno1 root tbf rate 512kbit latency 50ms burst 1540
      ;; and then cancel with:
      ;;   sudo tc qdisc del dev eno1 root
      (when (> cpu-usage .8)
        (set! %prefer-fast-decompression? #t))
      (when (< cpu-usage .2)
        (set! %prefer-fast-decompression? #f))

      (close-port hashed)
      (close-port input)

      ;; Wait for the reporter to finish.
      (every (compose zero? cdr waitpid) pids)

      ;; Skip a line after what 'progress-reporter/file' printed, and another
      ;; one to visually separate substitutions.  When PRINT-BUILD-TRACE? is
      ;; true, leave it up to (guix status) to prettify things.
      (newline (current-error-port))
      (unless print-build-trace?
        (newline (current-error-port)))

      ;; Check whether we got the data announced in NARINFO.
      (let ((actual (get-hash)))
        (if (bytevector=? actual expected)
            ;; Tell the daemon that we're done.
            (format port "success ~a ~a~%"
                    (narinfo-hash narinfo) (narinfo-size narinfo))
            ;; The actual data has a different hash than that in NARINFO.
            (format port "hash-mismatch ~a ~a ~a~%"
                    (hash-algorithm-name algorithm)
                    (bytevector->nix-base32-string expected)
                    (bytevector->nix-base32-string actual)))))))

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

(define (check-acl-initialized)
  "Warn if the ACL is uninitialized."
  (define (singleton? acl)
    ;; True if ACL contains just the user's public key.
    (and (file-exists? %public-key-file)
         (let ((key (call-with-input-file %public-key-file
                      (compose string->canonical-sexp
                               read-string))))
           (match acl
             ((thing)
              (equal? (canonical-sexp->string thing)
                      (canonical-sexp->string key)))
             (_
              #f)))))

  (let ((acl (acl->public-keys (current-acl))))
    (when (or (null? acl) (singleton? acl))
      (warning (G_ "ACL for archive imports seems to be uninitialized, \
substitutes may be unavailable\n")))))

(define (daemon-options)
  "Return a list of name/value pairs denoting build daemon options."
  (define %not-newline
    (char-set-complement (char-set #\newline)))

  (match (getenv "_NIX_OPTIONS")
    (#f                           ;should not happen when called by the daemon
     '())
    (newline-separated
     ;; Here we get something of the form "OPTION1=VALUE1\nOPTION2=VALUE2\n".
     (filter-map (lambda (option=value)
                   (match (string-index option=value #\=)
                     (#f                          ;invalid option setting
                      #f)
                     (equal-sign
                      (cons (string-take option=value equal-sign)
                            (string-drop option=value (+ 1 equal-sign))))))
                 (string-tokenize newline-separated %not-newline)))))

(define (find-daemon-option option)
  "Return the value of build daemon option OPTION, or #f if it could not be
found."
  (assoc-ref (daemon-options) option))

(define %default-substitute-urls
  (match (and=> (or (find-daemon-option "untrusted-substitute-urls") ;client
                    (find-daemon-option "substitute-urls"))          ;admin
                string-tokenize)
    ((urls ...)
     urls)
    (#f
     ;; This can only happen when this script is not invoked by the
     ;; daemon.
     '("http://ci.guix.gnu.org"))))

;; In order to prevent using large number of discovered local substitute
;; servers, limit the local substitute urls list size.
(define %max-substitute-urls 50)

(define* (randomize-substitute-urls urls
                                    #:key
                                    (max %max-substitute-urls))
  "Return a list containing MAX urls from URLS, picked randomly. If URLS list
is shorter than MAX elements, then it is directly returned."
  (define (random-item list)
    (list-ref list (random (length list))))

  (if (<= (length urls) max)
      urls
      (let loop ((res '())
                 (urls urls))
        (if (eq? (length res) max)
            res
            (let ((url (random-item urls)))
              (loop (cons url res) (delete url urls)))))))

(define %local-substitute-urls
  ;; If the following option is passed to the daemon, use the substitutes list
  ;; provided by "guix discover" process.
  (let* ((option (find-daemon-option "discover"))
         (discover? (and option (string=? option "true"))))
    (if discover?
     (randomize-substitute-urls (read-substitute-urls))
     '())))

(define substitute-urls
  ;; List of substitute URLs.
  (make-parameter (append %local-substitute-urls
                          %default-substitute-urls)))

(define (client-terminal-columns)
  "Return the number of columns in the client's terminal, if it is known, or a
default value."
  (or (and=> (or (find-daemon-option "untrusted-terminal-columns")
                 (find-daemon-option "terminal-columns"))
             (lambda (str)
               (let ((number (string->number str)))
                 (and number (max 20 (- number 1))))))
      80))

(define (validate-uri uri)
  (unless (string->uri uri)
    (leave (G_ "~a: invalid URI~%") uri)))

(define %reply-file-descriptor
  ;; The file descriptor where replies to the daemon must be sent, or #f to
  ;; use the current output port instead.
  (make-parameter 4))

(define-command (guix-substitute . args)
  (category internal)
  (synopsis "implement the build daemon's substituter protocol")

  (define print-build-trace?
    (match (or (find-daemon-option "untrusted-print-extended-build-trace")
               (find-daemon-option "print-extended-build-trace"))
      (#f #f)
      ((= string->number number) (> number 0))
      (_ #f)))

  (define deduplicate?
    (find-daemon-option "deduplicate"))

  (define reply-port
    ;; Port used to reply to the daemon.
    (if (%reply-file-descriptor)
        (fdopen (%reply-file-descriptor) "wl")
        (current-output-port)))

  (mkdir-p %narinfo-cache-directory)
  (maybe-remove-expired-cache-entries %narinfo-cache-directory
                                      cached-narinfo-files
                                      #:entry-expiration
                                      cached-narinfo-expiration-time
                                      #:cleanup-period
                                      %narinfo-expired-cache-entry-removal-delay)
  (check-acl-initialized)

  ;; Sanity-check SUBSTITUTE-URLS so we can provide a meaningful error
  ;; message.
  (for-each validate-uri (substitute-urls))

  ;; Attempt to install the client's locale so that messages are suitably
  ;; translated.  LC_CTYPE must be a UTF-8 locale; it's the case by default
  ;; so don't change it.
  (match (or (find-daemon-option "untrusted-locale")
             (find-daemon-option "locale"))
    (#f     #f)
    (locale (false-if-exception (setlocale LC_MESSAGES locale))))

  (catch 'system-error
    (lambda ()
      (set-thread-name "guix substitute"))
    (const #t))                                   ;GNU/Hurd lacks 'prctl'

  (with-networking
   (with-error-handling                           ; for signature errors
     (match args
       (("--query")
        (let ((acl (current-acl)))
          (let loop ((command (read-line)))
            (or (eof-object? command)
                (begin
                  (process-query reply-port command
                                 #:cache-urls (substitute-urls)
                                 #:acl acl)
                  (loop (read-line)))))))
       (("--substitute")
        ;; Download STORE-PATH and store it as a Nar in file DESTINATION.
        ;; Specify the number of columns of the terminal so the progress
        ;; report displays nicely.
        (parameterize ((current-terminal-columns (client-terminal-columns)))
          (let loop ()
            (match (read-line)
              ((? eof-object?)
               #t)
              ((= string-tokenize ("substitute" store-path destination))
               (process-substitution reply-port store-path destination
                                     #:cache-urls (substitute-urls)
                                     #:acl (current-acl)
                                     #:deduplicate? deduplicate?
                                     #:print-build-trace?
                                     print-build-trace?)
               (loop))))))
       ((or ("-V") ("--version"))
        (show-version-and-exit "guix substitute"))
       (("--help")
        (show-help))
       (opts
        (leave (G_ "~a: unrecognized options~%") opts))))))

;;; Local Variables:
;;; eval: (put 'with-timeout 'scheme-indent-function 1)
;;; eval: (put 'with-redirected-error-port 'scheme-indent-function 0)
;;; eval: (put 'with-cached-connection 'scheme-indent-function 2)
;;; eval: (put 'call-with-cached-connection 'scheme-indent-function 1)
;;; End:

;;; substitute.scm ends here

debug log:

solving 48309f9b3a ...
found 48309f9b3a in https://git.savannah.gnu.org/cgit/guix.git

(*) 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 external index

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

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.