summaryrefslogtreecommitdiff
path: root/guix/scripts/environment.scm
blob: b122b4cd406a5aed4cc9c7a4ffd372901d821cfc (about) (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
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
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2014, 2015 David Thompson <davet@gnu.org>
;;; Copyright © 2015, 2016 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 environment)
  #:use-module (guix ui)
  #:use-module (guix store)
  #:use-module (guix grafts)
  #:use-module (guix derivations)
  #:use-module (guix packages)
  #:use-module (guix profiles)
  #:use-module (guix search-paths)
  #:use-module (guix utils)
  #:use-module (guix build utils)
  #:use-module (guix monads)
  #:use-module ((guix gexp) #:select (lower-inputs))
  #:use-module (guix scripts)
  #:use-module (guix scripts build)
  #:use-module (gnu build linux-container)
  #:use-module (gnu system linux-container)
  #:use-module (gnu system file-systems)
  #:use-module (gnu packages)
  #:use-module (gnu packages bash)
  #:use-module (gnu packages commencement)
  #:use-module (gnu packages guile)
  #:use-module ((gnu packages bootstrap) #:select (%bootstrap-guile))
  #:use-module (ice-9 format)
  #:use-module (ice-9 match)
  #:use-module (ice-9 rdelim)
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-11)
  #:use-module (srfi srfi-26)
  #:use-module (srfi srfi-37)
  #:use-module (srfi srfi-98)
  #:export (guix-environment))

(define (evaluate-profile-search-paths profile search-paths)
  "Evaluate SEARCH-PATHS, a list of search-path specifications, for the
directories in PROFILE, the store path of a profile."
  (evaluate-search-paths search-paths (list profile)))

;; Protect some env vars from purification.  Borrowed from nix-shell.
(define %precious-variables
  '("HOME" "USER" "LOGNAME" "DISPLAY" "TERM" "TZ" "PAGER"))

(define %default-shell
  (or (getenv "SHELL") "/bin/sh"))

(define %network-configuration-files
  '("/etc/resolv.conf"
    "/etc/nsswitch.conf"
    "/etc/services"
    "/etc/hosts"))

(define (purify-environment)
  "Unset almost all environment variables.  A small number of variables such
as 'HOME' and 'USER' are left untouched."
  (for-each unsetenv
            (remove (cut member <> %precious-variables)
                    (match (get-environment-variables)
                      (((names . _) ...)
                       names)))))

(define (create-environment profile paths pure?)
  "Set the environment variables specified by PATHS for PROFILE.  When PURE?
is #t, unset the variables in the current environment.  Otherwise, augment
existing enviroment variables with additional search paths."
  (when pure? (purify-environment))
  (for-each (match-lambda
              ((($ <search-path-specification> variable _ separator) . value)
               (let ((current (getenv variable)))
                 (setenv variable
                         (if (and current (not pure?))
                             (string-append value separator current)
                             value)))))
            (evaluate-profile-search-paths profile paths))

  ;; Give users a way to know that they're in 'guix environment', so they can
  ;; adjust 'PS1' accordingly, for instance.
  (setenv "GUIX_ENVIRONMENT" "t"))

(define (show-search-paths profile search-paths pure?)
  "Display SEARCH-PATHS applied to PROFILE.  When PURE? is #t, do not augment
existing environment variables with additional search paths."
  (for-each (match-lambda
              ((search-path . value)
               (display
                (search-path-definition search-path value
                                        #:kind (if pure? 'exact 'prefix)))
               (newline)))
            (evaluate-profile-search-paths profile search-paths)))

(define (strip-input-name input)
  "Remove the name element from the tuple INPUT."
  (match input
    ((_ package) package)
    ((_ package output)
     (list package output))))

(define (package+propagated-inputs package output)
  "Return the union of PACKAGE's OUTPUT and its transitive propagated inputs."
  (cons (list package output)
        (map strip-input-name
             (package-transitive-propagated-inputs package))))

(define (package-or-package+output? expr)
  "Return #t if EXPR is a package or a 2 element list consisting of a package
and an output string."
  (match expr
    ((or (? package?) ; bare package object
         ((? package?) (? string?))) ; package+output tuple
     #t)
    (_ #f)))

(define (package-environment-inputs package)
  "Return a list of the transitive input packages for PACKAGE."
  ;; Remove non-package inputs such as origin records.
  (filter package-or-package+output?
          (map strip-input-name
               (bag-transitive-inputs
                (package->bag package)))))

(define (show-help)
  (display (_ "Usage: guix environment [OPTION]... PACKAGE... [-- COMMAND...]
Build an environment that includes the dependencies of PACKAGE and execute
COMMAND or an interactive shell in that environment.\n"))
  (display (_ "
  -e, --expression=EXPR  create environment for the package that EXPR
                         evaluates to"))
  (display (_ "
  -l, --load=FILE        create environment for the package that the code within
                         FILE evaluates to"))
  (display (_ "
      --ad-hoc           include all specified packages in the environment instead
                         of only their inputs"))
  (display (_ "
      --pure             unset existing environment variables"))
  (display (_ "
      --search-paths     display needed environment variable definitions"))
  (display (_ "
  -s, --system=SYSTEM    attempt to build for SYSTEM--e.g., \"i686-linux\""))
  (display (_ "
  -C, --container        run command within an isolated container"))
  (display (_ "
  -N, --network          allow containers to access the network"))
  (display (_ "
      --share=SPEC       for containers, share writable host file system
                         according to SPEC"))
  (display (_ "
      --expose=SPEC      for containers, expose read-only host file system
                         according to SPEC"))
  (display (_ "
      --bootstrap        use bootstrap binaries to build the environment"))
  (newline)
  (show-build-options-help)
  (newline)
  (display (_ "
  -h, --help             display this help and exit"))
  (display (_ "
  -V, --version          display version information and exit"))
  (newline)
  (show-bug-report-information))

(define %default-options
  `((system . ,(%current-system))
    (substitutes? . #t)
    (graft? . #t)
    (max-silent-time . 3600)
    (verbosity . 0)))

(define (tag-package-arg opts arg)
  "Return a two-element list with the form (TAG ARG) that tags ARG with either
'ad-hoc' in OPTS has the 'ad-hoc?' key set to #t, or 'inputs' otherwise."
  ;; Normally, the transitive inputs to a package are added to an environment,
  ;; but the ad-hoc? flag changes the meaning of a package argument such that
  ;; the package itself is added to the environment instead.
  (if (assoc-ref opts 'ad-hoc?)
      `(ad-hoc-package ,arg)
      `(package ,arg)))

(define %options
  ;; Specification of the command-line options.
  (cons* (option '(#\h "help") #f #f
                 (lambda args
                   (show-help)
                   (exit 0)))
         (option '(#\V "version") #f #f
                 (lambda args
                   (show-version-and-exit "guix environment")))
         (option '("pure") #f #f
                 (lambda (opt name arg result)
                   (alist-cons 'pure #t result)))
         (option '(#\E "exec") #t #f ; deprecated
                 (lambda (opt name arg result)
                   (alist-cons 'exec (list %default-shell "-c" arg) result)))
         (option '("search-paths") #f #f
                 (lambda (opt name arg result)
                   (alist-cons 'search-paths #t result)))
         (option '(#\l "load") #t #f
                 (lambda (opt name arg result)
                   (alist-cons 'load
                               (tag-package-arg result arg)
                               result)))
         (option '(#\e "expression") #t #f
                 (lambda (opt name arg result)
                   (alist-cons 'expression
                               (tag-package-arg result arg)
                               result)))
         (option '("ad-hoc") #f #f
                 (lambda (opt name arg result)
                   (alist-cons 'ad-hoc? #t result)))
         (option '(#\n "dry-run") #f #f
                 (lambda (opt name arg result)
                   (alist-cons 'dry-run? #t result)))
         (option '(#\s "system") #t #f
                 (lambda (opt name arg result)
                   (alist-cons 'system arg
                               (alist-delete 'system result eq?))))
         (option '(#\C "container") #f #f
                 (lambda (opt name arg result)
                   (alist-cons 'container? #t result)))
         (option '(#\N "network") #f #f
                 (lambda (opt name arg result)
                   (alist-cons 'network? #t result)))
         (option '("share") #t #f
                 (lambda (opt name arg result)
                   (alist-cons 'file-system-mapping
                               (specification->file-system-mapping arg #t)
                               result)))
         (option '("expose") #t #f
                 (lambda (opt name arg result)
                   (alist-cons 'file-system-mapping
                               (specification->file-system-mapping arg #f)
                               result)))
         (option '("bootstrap") #f #f
                 (lambda (opt name arg result)
                   (alist-cons 'bootstrap? #t result)))
         %standard-build-options))

(define (pick-all alist key)
  "Return a list of values in ALIST associated with KEY."
  (define same-key? (cut eq? key <>))

  (fold (lambda (pair memo)
          (match pair
            (((? same-key? k) . v)
             (cons v memo))
            (_ memo)))
        '() alist))

(define (compact lst)
  "Remove all #f elements from LST."
  (filter identity lst))

(define (options/resolve-packages opts)
  "Return OPTS with package specification strings replaced by actual
packages."
  (define (package->output package mode)
    (match package
      ((? package?)
       (list mode package "out"))
      (((? package? package) (? string? output))
       (list mode package output))))

  (define (packages->outputs packages mode)
    (match packages
      ((? package-or-package+output? package) ; single package
       (list (package->output package mode)))
      (((? package-or-package+output?) ...) ; many packages
       (map (cut package->output <> mode) packages))))

  (compact
   (append-map (match-lambda
                 (('package mode (? string? spec))
                  (let-values (((package output)
                                (specification->package+output spec)))
                    (list (list mode package output))))
                 (('expression mode str)
                  ;; Add all the outputs of the package STR evaluates to.
                  (packages->outputs (read/eval str) mode))
                 (('load mode file)
                  ;; Add all the outputs of the package defined in FILE.
                  (let ((module (make-user-module '())))
                    (packages->outputs (load* file module) mode)))
                 (_ '(#f)))
               opts)))

(define* (build-environment derivations opts)
  "Build the DERIVATIONS required by the environment using the build options
in OPTS."
  (let ((substitutes? (assoc-ref opts 'substitutes?))
        (dry-run?     (assoc-ref opts 'dry-run?)))
    (mbegin %store-monad
      (show-what-to-build* derivations
                           #:use-substitutes? substitutes?
                           #:dry-run? dry-run?)
      (if dry-run?
          (return #f)
          (mbegin %store-monad
            (set-build-options-from-command-line* opts)
            (built-derivations derivations))))))

(define (inputs->profile-derivation inputs system bootstrap?)
  "Return the derivation for a profile consisting of INPUTS for SYSTEM.
BOOTSTRAP?  specifies whether to use the bootstrap Guile to build the
profile."
  (profile-derivation (packages->manifest inputs)
                      #:system system
                      #:hooks (if bootstrap?
                                  '()
                                  %default-profile-hooks)))

(define requisites* (store-lift requisites))

(define (inputs->requisites inputs)
  "Convert INPUTS, a list of input tuples or store path strings, into a set of
requisite store items i.e. the union closure of all the inputs."
  (define (input->requisites input)
    (requisites*
     (match input
       ((drv output)
        (derivation->output-path drv output))
       ((drv)
        (derivation->output-path drv))
       ((? direct-store-path? path)
        path))))

  (mlet %store-monad ((reqs (sequence %store-monad
                                      (map input->requisites inputs))))
    (return (delete-duplicates (concatenate reqs)))))

(define (status->exit-code status)
  "Compute the exit code made from STATUS, a value as returned by 'waitpid',
and suitable for 'exit'."
  ;; See <bits/waitstatus.h>.
  (or (status:exit-val status)
      (logior #x80 (status:term-sig status))))

(define exit/status (compose exit status->exit-code))
(define primitive-exit/status (compose primitive-exit status->exit-code))

(define (launch-environment command inputs paths pure?)
  "Run COMMAND in a new environment containing INPUTS, using the native search
paths defined by the list PATHS.  When PURE?, pre-existing environment
variables are cleared before setting the new ones."
  (create-environment inputs paths pure?)
  (apply system* command))

(define* (launch-environment/container #:key command bash user-mappings
                                       profile paths network?)
  "Run COMMAND within a container that features the software in PROFILE.
Environment variables are set according to PATHS, a list of native search
paths.  The global shell is BASH, a file name for a GNU Bash binary in the
store.  When NETWORK?, access to the host system network is permitted.
USER-MAPPINGS, a list of file system mappings, contains the user-specified
host file systems to mount inside the container."
  (mlet %store-monad ((reqs (inputs->requisites
                             (list (direct-store-path bash) profile))))
    (return
     (let* ((cwd (getcwd))
            ;; Bind-mount all requisite store items, user-specified mappings,
            ;; /bin/sh, the current working directory, and possibly networking
            ;; configuration files within the container.
            (mappings
             (append user-mappings
                     ;; Current working directory.
                     (list (file-system-mapping
                            (source cwd)
                            (target cwd)
                            (writable? #t)))
                     ;; When in Rome, do as Nix build.cc does: Automagically
                     ;; map common network configuration files.
                     (if network?
                         (filter-map (lambda (file)
                                       (and (file-exists? file)
                                            (file-system-mapping
                                             (source file)
                                             (target file)
                                             (writable? #f))))
                                     %network-configuration-files)
                         '())
                     ;; Mappings for the union closure of all inputs.
                     (map (lambda (dir)
                            (file-system-mapping
                             (source dir)
                             (target dir)
                             (writable? #f)))
                          reqs)))
            (file-systems (append %container-file-systems
                                  (map mapping->file-system mappings))))
       (exit/status
        (call-with-container (map file-system->spec file-systems)
          (lambda ()
            ;; Setup global shell.
            (mkdir-p "/bin")
            (symlink bash "/bin/sh")

            ;; Setup directory for temporary files.
            (mkdir-p "/tmp")
            (for-each (lambda (var)
                        (setenv var "/tmp"))
                      ;; The same variables as in Nix's 'build.cc'.
                      '("TMPDIR" "TEMPDIR" "TMP" "TEMP"))

            ;; From Nix build.cc:
            ;;
            ;; Set HOME to a non-existing path to prevent certain
            ;; programs from using /etc/passwd (or NIS, or whatever)
            ;; to locate the home directory (for example, wget looks
            ;; for ~/.wgetrc).  I.e., these tools use /etc/passwd if
            ;; HOME is not set, but they will just assume that the
            ;; settings file they are looking for does not exist if
            ;; HOME is set but points to some non-existing path.
            (setenv "HOME" "/homeless-shelter")

            ;; For convenience, start in the user's current working
            ;; directory rather than the root directory.
            (chdir cwd)

            (primitive-exit/status
             ;; A container's environment is already purified, so no need to
             ;; request it be purified again.
             (launch-environment command profile paths #f)))
          #:namespaces (if network?
                           (delq 'net %namespaces) ; share host network
                           %namespaces)))))))

(define (environment-bash container? bootstrap? system)
  "Return a monadic value in the store monad for the version of GNU Bash
needed in the environment for SYSTEM, if any.  If CONTAINER? is #f, return #f.
If CONTAINER? and BOOTSTRAP?, return the store path for the bootstrap Bash.
Otherwise, return the derivation for the Bash package."
  (with-monad %store-monad
    (cond
     ((and container? (not bootstrap?))
      (package->derivation bash))
     ;; Use the bootstrap Bash instead.
     ((and container? bootstrap?)
      (interned-file
       (search-bootstrap-binary "bash" system)))
     (else
      (return #f)))))

(define (parse-args args)
  "Parse the list of command line arguments ARGS."
  (define (handle-argument arg result)
    (alist-cons 'package (tag-package-arg result arg) result))

  ;; The '--' token is used to separate the command to run from the rest of
  ;; the operands.
  (let-values (((args command) (split args "--")))
    (let ((opts (parse-command-line args %options (list %default-options)
                                    #:argument-handler handle-argument)))
      (if (null? command)
          opts
          (alist-cons 'exec command opts)))))

(define (assert-container-features)
  "Check if containers can be created and exit with an informative error
message if any test fails."
  (unless (user-namespace-supported?)
    (report-error (_ "cannot create container: user namespaces unavailable\n"))
    (leave (_ "is your kernel version < 3.10?\n")))

  (unless (unprivileged-user-namespace-supported?)
    (report-error (_ "cannot create container: unprivileged user cannot create user namespaces\n"))
    (leave (_ "please set /proc/sys/kernel/unprivileged_userns_clone to \"1\"\n")))

  (unless (setgroups-supported?)
    (report-error (_ "cannot create container: /proc/self/setgroups does not exist\n"))
    (leave (_ "is your kernel version < 3.19?\n"))))

;; Entry point.
(define (guix-environment . args)
  (with-error-handling
    (let* ((opts       (parse-args args))
           (pure?      (assoc-ref opts 'pure))
           (container? (assoc-ref opts 'container?))
           (network?   (assoc-ref opts 'network?))
           (bootstrap? (assoc-ref opts 'bootstrap?))
           (system     (assoc-ref opts 'system))
           (command    (or (assoc-ref opts 'exec)
                           ;; Spawn a shell if the user didn't specify
                           ;; anything in particular.
                           (if container?
                               ;; The user's shell is likely not available
                               ;; within the container.
                               '("/bin/sh")
                               (list %default-shell))))
           (packages   (options/resolve-packages opts))
           (mappings   (pick-all opts 'file-system-mapping))
           (inputs     (delete-duplicates
                        (append-map (match-lambda
                                      (('ad-hoc-package package output)
                                       (package+propagated-inputs package
                                                                  output))
                                      (('package package _)
                                       (package-environment-inputs package)))
                                    packages)))
           (paths      (delete-duplicates
                        (cons $PATH
                              (append-map (match-lambda
                                            ((or ((? package? p) _ ...)
                                                 (? package? p))
                                             (package-native-search-paths p))
                                            (_ '()))
                                          inputs))
                        eq?)))

      (when container? (assert-container-features))

      (with-store store
        ;; Use the bootstrap Guile when requested.
        (parameterize ((%graft? (assoc-ref opts 'graft?))
                       (%guile-for-build
                        (package-derivation
                         store
                         (if bootstrap?
                             %bootstrap-guile
                             (canonical-package guile-2.0)))))
          (set-build-options-from-command-line store opts)
          (run-with-store store
            ;; Containers need a Bourne shell at /bin/sh.
            (mlet* %store-monad ((bash       (environment-bash container?
                                                               bootstrap?
                                                               system))
                                 (prof-drv   (inputs->profile-derivation
                                              inputs system bootstrap?))
                                 (profile -> (derivation->output-path prof-drv)))
              ;; First build the inputs.  This is necessary even for
              ;; --search-paths.  Additionally, we might need to build bash for
              ;; a container.
              (mbegin %store-monad
                (build-environment (if (derivation? bash)
                                       (list prof-drv bash)
                                       (list prof-drv))
                                   opts)
                (cond
                 ((assoc-ref opts 'dry-run?)
                  (return #t))
                 ((assoc-ref opts 'search-paths)
                  (show-search-paths profile paths pure?)
                  (return #t))
                 (container?
                  (let ((bash-binary
                         (if bootstrap?
                             bash
                             (string-append (derivation->output-path bash)
                                            "/bin/sh"))))
                    (launch-environment/container #:command command
                                                  #:bash bash-binary
                                                  #:user-mappings mappings
                                                  #:profile profile
                                                  #:paths paths
                                                  #:network? network?)))
                 (else
                  (return
                   (exit/status
                    (launch-environment command profile paths pure?)))))))))))))