summaryrefslogtreecommitdiff
path: root/guix/channels.scm
blob: 6b860f3bd81654acac84c599614217547ba2834c (plain)
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
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2018, 2019 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2018 Ricardo Wurmus <rekado@elephly.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 channels)
  #:use-module (guix git)
  #:use-module (guix records)
  #:use-module (guix gexp)
  #:use-module (guix discovery)
  #:use-module (guix monads)
  #:use-module (guix profiles)
  #:use-module (guix derivations)
  #:use-module (guix store)
  #:use-module (guix i18n)
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-2)
  #:use-module (srfi srfi-9)
  #:use-module (srfi srfi-11)
  #:autoload   (guix self) (whole-package)
  #:use-module (ice-9 match)
  #:export (channel
            channel?
            channel-name
            channel-url
            channel-branch
            channel-commit
            channel-location

            %default-channels

            channel-instance?
            channel-instance-channel
            channel-instance-commit
            channel-instance-checkout

            latest-channel-instances
            checkout->channel-instance
            latest-channel-derivation
            channel-instances->manifest
            channel-instances->derivation))

;;; Commentary:
;;;
;;; This module implements "channels."  A channel is usually a source of
;;; package definitions.  There's a special channel, the 'guix' channel, that
;;; provides all of Guix, including its commands and its documentation.
;;; User-defined channels are expected to typically provide a bunch of .scm
;;; files meant to be added to the '%package-search-path'.
;;;
;;; This module provides tools to fetch and update channels from a Git
;;; repository and to build them.
;;;
;;; Code:

(define-record-type* <channel> channel make-channel
  channel?
  (name      channel-name)
  (url       channel-url)
  (branch    channel-branch (default "master"))
  (commit    channel-commit (default #f))
  (location  channel-location
             (default (current-source-location)) (innate)))

(define %default-channels
  ;; Default list of channels.
  (list (channel
         (name 'guix)
         (branch "master")
         (url "https://git.savannah.gnu.org/git/guix.git"))))

(define (guix-channel? channel)
  "Return true if CHANNEL is the 'guix' channel."
  (eq? 'guix (channel-name channel)))

(define-record-type <channel-instance>
  (channel-instance channel commit checkout)
  channel-instance?
  (channel   channel-instance-channel)
  (commit    channel-instance-commit)
  (checkout  channel-instance-checkout))

(define-record-type <channel-metadata>
  (channel-metadata version dependencies)
  channel-metadata?
  (version       channel-metadata-version)
  (dependencies  channel-metadata-dependencies))

(define (channel-reference channel)
  "Return the \"reference\" for CHANNEL, an sexp suitable for
'latest-repository-commit'."
  (match (channel-commit channel)
    (#f      `(branch . ,(channel-branch channel)))
    (commit  `(commit . ,(channel-commit channel)))))

(define (read-channel-metadata instance)
  "Return a channel-metadata record read from the channel INSTANCE's
description file, or return #F if the channel instance does not include the
file."
  (let* ((source (channel-instance-checkout instance))
         (meta-file (string-append source "/.guix-channel")))
    (and (file-exists? meta-file)
         (and-let* ((raw (call-with-input-file meta-file read))
                    (version (and=> (assoc-ref raw 'version) first))
                    (dependencies (or (assoc-ref raw 'dependencies) '())))
           (channel-metadata
            version
            (map (lambda (item)
                   (let ((get (lambda* (key #:optional default)
                                (or (and=> (assoc-ref item key) first) default))))
                     (and-let* ((name (get 'name))
                                (url (get 'url))
                                (branch (get 'branch "master")))
                       (channel
                        (name name)
                        (branch branch)
                        (url url)
                        (commit (get 'commit))))))
                 dependencies))))))

(define (channel-instance-dependencies instance)
  "Return the list of channels that are declared as dependencies for the given
channel INSTANCE."
  (match (read-channel-metadata instance)
    (#f '())
    (($ <channel-metadata> version dependencies)
     dependencies)))

(define* (latest-channel-instances store channels #:optional (previous-channels '()))
  "Return a list of channel instances corresponding to the latest checkouts of
CHANNELS and the channels on which they depend.  PREVIOUS-CHANNELS is a list
of previously processed channels."
  ;; Only process channels that are unique, or that are more specific than a
  ;; previous channel specification.
  (define (ignore? channel others)
    (member channel others
            (lambda (a b)
              (and (eq? (channel-name a) (channel-name b))
                   (or (channel-commit b)
                       (not (or (channel-commit a)
                                (channel-commit b))))))))
  ;; Accumulate a list of instances.  A list of processed channels is also
  ;; accumulated to decide on duplicate channel specifications.
  (match (fold (lambda (channel acc)
                 (match acc
                   ((#:channels previous-channels #:instances instances)
                    (if (ignore? channel previous-channels)
                        acc
                        (begin
                          (format (current-error-port)
                                  (G_ "Updating channel '~a' from Git repository at '~a'...~%")
                                  (channel-name channel)
                                  (channel-url channel))
                          (let-values (((checkout commit)
                                        (latest-repository-commit store (channel-url channel)
                                                                  #:ref (channel-reference
                                                                         channel))))
                            (let ((instance (channel-instance channel commit checkout)))
                              (let-values (((new-instances new-channels)
                                            (latest-channel-instances
                                             store
                                             (channel-instance-dependencies instance)
                                             previous-channels)))
                                `(#:channels
                                  ,(append (cons channel new-channels)
                                           previous-channels)
                                  #:instances
                                  ,(append (cons instance new-instances)
                                           instances))))))))))
               `(#:channels ,previous-channels #:instances ())
               channels)
    ((#:channels channels #:instances instances)
     (let ((instance-name (compose channel-name channel-instance-channel)))
       ;; Remove all earlier channel specifications if they are followed by a
       ;; more specific one.
       (values (delete-duplicates instances
                                  (lambda (a b)
                                    (eq? (instance-name a) (instance-name b))))
               channels)))))

(define* (checkout->channel-instance checkout
                                     #:key commit
                                     (url checkout) (name 'guix))
  "Return a channel instance for CHECKOUT, which is assumed to be a checkout
of COMMIT at URL.  Use NAME as the channel name."
  (let* ((commit  (or commit (make-string 40 #\0)))
         (channel (channel (name name)
                           (commit commit)
                           (url url))))
    (channel-instance channel commit checkout)))

(define %self-build-file
  ;; The file containing code to build Guix.  This serves the same purpose as
  ;; a makefile, and, similarly, is intended to always keep this name.
  "build-aux/build-self.scm")

(define %pull-version
  ;; This is the version of the 'guix pull' protocol.  It specifies what's
  ;; expected from %SELF-BUILD-FILE.  The initial version ("0") was when we'd
  ;; place a set of compiled Guile modules in ~/.config/guix/latest.
  1)

(define (standard-module-derivation name source dependencies)
  "Return a derivation that builds the Scheme modules in SOURCE and that
depend on DEPENDENCIES, a list of lowerable objects.  The assumption is that
SOURCE contains package modules to be added to '%package-module-path'."
  (define modules
    (scheme-modules* source))

  ;; FIXME: We should load, say SOURCE/.guix-channel.scm, which would allow
  ;; channel publishers to specify things such as the sub-directory where .scm
  ;; files live, files to exclude from the channel, preferred substitute URLs,
  ;; etc.
  (mlet* %store-monad ((compiled
                        (compiled-modules modules
                                          #:name name
                                          #:module-path (list source)
                                          #:extensions dependencies)))

    (gexp->derivation name
                      (with-extensions dependencies
                        (with-imported-modules '((guix build utils))
                          #~(begin
                              (use-modules (guix build utils))

                              (let ((go  (string-append #$output "/lib/guile/"
                                                        (effective-version)
                                                        "/site-ccache"))
                                    (scm (string-append #$output
                                                        "/share/guile/site/"
                                                        (effective-version))))
                                (mkdir-p (dirname go))
                                (symlink #$compiled go)
                                (mkdir-p (dirname scm))
                                (symlink #$source scm))))))))

(define* (build-from-source name source
                            #:key verbose? commit
                            (dependencies '()))
  "Return a derivation to build Guix from SOURCE, using the self-build script
contained therein.  Use COMMIT as the version string."
  ;; Running the self-build script makes it easier to update the build
  ;; procedure: the self-build script of the Guix-to-be-installed contains the
  ;; right dependencies, build procedure, etc., which the Guix-in-use may not
  ;; be know.
  (define script
    (string-append source "/" %self-build-file))

  (if (file-exists? script)
      (let ((build (save-module-excursion
                    (lambda ()
                      (primitive-load script)))))
        ;; BUILD must be a monadic procedure of at least one argument: the
        ;; source tree.
        ;;
        ;; Note: BUILD can return #f if it does not support %PULL-VERSION.  In
        ;; the future we'll fall back to a previous version of the protocol
        ;; when that happens.
        (build source #:verbose? verbose? #:version commit
               #:pull-version %pull-version))

      ;; Build a set of modules that extend Guix using the standard method.
      (standard-module-derivation name source dependencies)))

(define* (build-channel-instance instance #:optional (dependencies '()))
  "Return, as a monadic value, the derivation for INSTANCE, a channel
instance.  DEPENDENCIES is a list of extensions providing Guile modules that
INSTANCE depends on."
  (build-from-source (symbol->string
                      (channel-name (channel-instance-channel instance)))
                     (channel-instance-checkout instance)
                     #:commit (channel-instance-commit instance)
                     #:dependencies dependencies))

(define (channel-instance-derivations instances)
  "Return the list of derivations to build INSTANCES, in the same order as
INSTANCES."
  (define core-instance
    ;; The 'guix' channel is treated specially: it's an implicit dependency of
    ;; all the other channels.
    (find (lambda (instance)
            (guix-channel? (channel-instance-channel instance)))
          instances))

  (define dependencies
    ;; Dependencies of CORE-INSTANCE.
    ;; FIXME: It would be best not to hard-wire this information here and
    ;; instead query it to CORE-INSTANCE.
    (list (module-ref (resolve-interface '(gnu packages gnupg))
                      'guile-gcrypt)
          (module-ref (resolve-interface '(gnu packages guile))
                      'guile-git)
          (module-ref (resolve-interface '(gnu packages guile))
                      'guile-bytestructures)))

  (mlet %store-monad ((core (build-channel-instance core-instance)))
    (mapm %store-monad
          (lambda (instance)
            (if (eq? instance core-instance)
                (return core)
                (match (channel-instance-dependencies instance)
                  (()
                   (build-channel-instance instance
                                           (cons core dependencies)))
                  (channels
                   (mlet %store-monad ((dependencies-derivation
                                        (latest-channel-derivation
                                         ;; %default-channels is used here to
                                         ;; ensure that the core channel is
                                         ;; available for channels declared as
                                         ;; dependencies.
                                         (append channels %default-channels))))
                     (build-channel-instance instance
                                             (cons dependencies-derivation
                                                   (cons core dependencies))))))))
          instances)))

(define (whole-package-for-legacy name modules)
  "Return a full-blown Guix package for MODULES, a derivation that builds Guix
modules in the old ~/.config/guix/latest style."
  (define packages
    (resolve-interface '(gnu packages guile)))

  (define modules+compiled
    ;; Since MODULES contains both .scm and .go files at its root, re-bundle
    ;; it so that it has share/guile/site and lib/guile, which is what
    ;; 'whole-package' expects.
    (computed-file (derivation-name modules)
                   (with-imported-modules '((guix build utils))
                     #~(begin
                         (use-modules (guix build utils))

                         (define version
                           (effective-version))
                         (define share
                           (string-append #$output "/share/guile/site"))
                         (define lib
                           (string-append #$output "/lib/guile/" version))

                         (mkdir-p share) (mkdir-p lib)
                         (symlink #$modules (string-append share "/" version))
                         (symlink #$modules (string-append lib "/site-ccache"))))))

  (letrec-syntax ((list (syntax-rules (->)
                          ((_)
                           '())
                          ((_ (module -> variable) rest ...)
                           (cons (module-ref (resolve-interface
                                              '(gnu packages module))
                                             'variable)
                                 (list rest ...)))
                          ((_ variable rest ...)
                           (cons (module-ref packages 'variable)
                                 (list rest ...))))))
    (whole-package name modules+compiled

                   ;; In the "old style", %SELF-BUILD-FILE would simply return a
                   ;; derivation that builds modules.  We have to infer what the
                   ;; dependencies of these modules were.
                   (list guile-json guile-git guile-bytestructures
                         (ssh -> guile-ssh) (tls -> gnutls)))))

(define (old-style-guix? drv)
  "Return true if DRV corresponds to a ~/.config/guix/latest style of
derivation."
  ;; Here we rely on a gross historical fact: that derivations produced by the
  ;; "old style" (before commit 8a0d9bc8a3f153159d9e239a151c0fa98f1e12d8,
  ;; dated May 30, 2018) did not depend on "guix-command.drv".
  (not (find (lambda (input)
               (string-suffix? "-guix-command.drv"
                               (derivation-input-path input)))
             (derivation-inputs drv))))

(define (channel-instances->manifest instances)
  "Return a profile manifest with entries for all of INSTANCES, a list of
channel instances."
  (define instance->entry
    (match-lambda
      ((instance drv)
       (let ((commit  (channel-instance-commit instance))
             (channel (channel-instance-channel instance)))
         (with-monad %store-monad
           (return (manifest-entry
                     (name (symbol->string (channel-name channel)))
                     (version (string-take commit 7))
                     (item (if (guix-channel? channel)
                               (if (old-style-guix? drv)
                                   (whole-package-for-legacy
                                    (string-append name "-" version)
                                    drv)
                                   drv)
                               drv))
                     (properties
                      `((source (repository
                                 (version 0)
                                 (url ,(channel-url channel))
                                 (branch ,(channel-branch channel))
                                 (commit ,commit))))))))))))

  (mlet* %store-monad ((derivations (channel-instance-derivations instances))
                       (entries     (mapm %store-monad instance->entry
                                          (zip instances derivations))))
    (return (manifest entries))))

(define (channel-instances->derivation instances)
  "Return the derivation of the profile containing INSTANCES, a list of
channel instances."
  (mlet %store-monad ((manifest (channel-instances->manifest instances)))
    (profile-derivation manifest)))

(define latest-channel-instances*
  (store-lift latest-channel-instances))

(define* (latest-channel-derivation #:optional (channels %default-channels))
  "Return as a monadic value the derivation that builds the profile for the
latest instances of CHANNELS."
  (mlet %store-monad ((instances (latest-channel-instances* channels)))
    (channel-instances->derivation instances)))