aboutsummaryrefslogtreecommitdiff
path: root/gnu/home/services.scm
blob: e154f5c44344f584b71d56ccfd33b31ac8734461 (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
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
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2021 Andrew Tropin <andrew@trop.in>
;;; Copyright © 2021 Xinglu Chen <public@yoctocell.xyz>
;;;
;;; 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 (gnu home services)
  #:use-module (gnu services)
  #:use-module ((gnu packages package-management) #:select (guix))
  #:use-module ((gnu packages base) #:select (coreutils))
  #:use-module (guix channels)
  #:use-module (guix monads)
  #:use-module (guix store)
  #:use-module (guix gexp)
  #:use-module (guix profiles)
  #:use-module (guix sets)
  #:use-module (guix ui)
  #:use-module (guix discovery)
  #:use-module (guix diagnostics)
  #:use-module (guix i18n)
  #:use-module (guix modules)
  #:use-module (srfi srfi-1)
  #:use-module (ice-9 match)
  #:use-module (ice-9 vlist)

  #:export (home-service-type
            home-profile-service-type
            home-environment-variables-service-type
            home-files-service-type
            home-xdg-configuration-files-service-type
            home-xdg-data-files-service-type
            home-run-on-first-login-service-type
            home-activation-service-type
            home-run-on-change-service-type
            home-provenance-service-type

            environment-variable-shell-definitions
            home-files-directory
            xdg-configuration-files-directory
            xdg-data-files-directory

            fold-home-service-types
            lookup-home-service-types
            home-provenance

            %initialize-gettext)

  #:re-export (service
               service-type
               service-extension))

;;; Comment:
;;;
;;; This module is similar to (gnu system services) module, but
;;; provides Home Services, which are supposed to be used for building
;;; home-environment.
;;;
;;; Home Services use the same extension as System Services.  Consult
;;; (gnu system services) module or manual for more information.
;;;
;;; home-service-type is a root of home services DAG.
;;;
;;; home-profile-service-type is almost the same as profile-service-type, at least
;;; for now.
;;;
;;; home-environment-variables-service-type generates a @file{setup-environment}
;;; shell script, which is expected to be sourced by login shell or other program,
;;; which starts early and spawns all other processes.  Home services for shells
;;; automatically add code for sourcing this file, if person do not use those home
;;; services they have to source this script manually in their's shell *profile
;;; file (details described in the manual).
;;;
;;; home-files-service-type is similar to etc-service-type, but doesn't extend
;;; home-activation, because deploy mechanism for config files is pluggable
;;; and can be different for different home environments: The default one is
;;; called symlink-manager, which creates links for various dotfiles and xdg
;;; configuration files to store, but is possible to implement alternative
;;; approaches like read-only home from Julien's guix-home-manager.
;;;
;;; home-run-on-first-login-service-type provides an @file{on-first-login} guile
;;; script, which runs provided gexps once, when user makes first login.  It can
;;; be used to start user's Shepherd and maybe some other process.  It relies on
;;; assumption that /run/user/$UID will be created on login by some login
;;; manager (elogind for example).
;;;
;;; home-activation-service-type provides an @file{activate} guile script, which
;;; do three main things:
;;;
;;; - Sets environment variables to the values declared in
;;; @file{setup-environment} shell script.  It's necessary, because user can set
;;; for example XDG_CONFIG_HOME and it should be respected by activation gexp of
;;; symlink-manager.
;;;
;;; - Sets GUIX_NEW_HOME and possibly GUIX_OLD_HOME vars to paths in the store.
;;; Later those variables can be used by activation gexps, for example by
;;; symlink-manager or run-on-change services.
;;;
;;; - Run all activation gexps provided by other home services.
;;;
;;; home-run-on-change-service-type allows to trigger actions during
;;; activation if file or directory specified by pattern is changed.
;;;
;;; Code:


(define (home-derivation entries mextensions)
  "Return as a monadic value the derivation of the 'home'
directory containing the given entries."
  (mlet %store-monad ((extensions (mapm/accumulate-builds identity
                                                          mextensions)))
    (lower-object
     (file-union "home" (append entries (concatenate extensions))))))

(define home-service-type
  ;; This is the ultimate service type, the root of the home service
  ;; DAG.  The service of this type is extended by monadic name/item
  ;; pairs.  These items end up in the "home-environment directory" as
  ;; returned by 'home-environment-derivation'.
  (service-type (name 'home)
                (extensions '())
                (compose identity)
                (extend home-derivation)
                (default-value '())
                (description
                 "Build the home environment top-level directory,
which in turn refers to everything the home environment needs: its
packages, configuration files, activation script, and so on.")))

(define (packages->profile-entry packages)
  "Return a system entry for the profile containing PACKAGES."
  ;; XXX: 'mlet' is needed here for one reason: to get the proper
  ;; '%current-target' and '%current-target-system' bindings when
  ;; 'packages->manifest' is called, and thus when the 'package-inputs'
  ;; etc. procedures are called on PACKAGES.  That way, conditionals in those
  ;; inputs see the "correct" value of these two parameters.  See
  ;; <https://issues.guix.gnu.org/44952>.
  (mlet %store-monad ((_ (current-target-system)))
    (return `(("profile" ,(profile
                           (content (packages->manifest
                                     (map identity
                                     ;;(options->transformation transformations)
                                     (delete-duplicates packages eq?))))))))))

;; MAYBE: Add a list of transformations for packages.  It's better to
;; place it in home-profile-service-type to affect all profile
;; packages and prevent conflicts, when other packages relies on
;; non-transformed version of package.
(define home-profile-service-type
  (service-type (name 'home-profile)
                (extensions
                 (list (service-extension home-service-type
                                          packages->profile-entry)))
                (compose concatenate)
                (extend append)
                (description
                 "This is the @dfn{home profile} and can be found in
@file{~/.guix-home/profile}.  It contains packages and
configuration files that the user has declared in their
@code{home-environment} record.")))

(define (environment-variable-shell-definitions variables)
  "Return a gexp that evaluates to a list of POSIX shell statements defining
VARIABLES, a list of environment variable name/value pairs.  The returned code
ensures variable values are properly quoted."
  #~(let ((shell-quote
           (lambda (value)
             ;; Double-quote VALUE, leaving dollar sign as is.
             (let ((quoted (list->string
                            (string-fold-right
                             (lambda (chr lst)
                               (case chr
                                 ((#\" #\\)
                                  (append (list chr #\\) lst))
                                 (else (cons chr lst))))
                             '()
                             value))))
               (string-append "\"" quoted "\"")))))
      (string-append
       #$@(map (match-lambda
                 ((key . #f)
                  "")
                 ((key . #t)
                  #~(string-append "export " #$key "\n"))
                 ((key . value)
                  #~(string-append "export " #$key "="
                                   (shell-quote #$value) "\n")))
               variables))))

(define (environment-variables->setup-environment-script vars)
  "Return a file that can be sourced by a POSIX compliant shell which
initializes the environment.  The file will source the home
environment profile, set some default environment variables, and set
environment variables provided in @code{vars}.  @code{vars} is a list
of pairs (@code{(key . value)}), @code{key} is a string and
@code{value} is a string or gexp.

If value is @code{#f} variable will be omitted.
If value is @code{#t} variable will be just exported.
For any other, value variable will be set to the @code{value} and
exported."
  (define (warn-about-duplicate-definitions)
    (fold
     (lambda (x acc)
       (when (equal? (car x) (car acc))
         (warning
          (G_ "duplicate definition for `~a' environment variable ~%") (car x)))
       x)
     (cons "" "")
     (sort vars (lambda (a b)
                  (string<? (car a) (car b))))))

  (warn-about-duplicate-definitions)
  (with-monad
   %store-monad
   (return
    `(("setup-environment"
       ;; TODO: It's necessary to source ~/.guix-profile too
       ;; on foreign distros
       ,(computed-file "setup-environment"
                       #~(call-with-output-file #$output
                           (lambda (port)
                             (set-port-encoding! port "UTF-8")
                             (display "\
HOME_ENVIRONMENT=$HOME/.guix-home
GUIX_PROFILE=\"$HOME_ENVIRONMENT/profile\"
PROFILE_FILE=\"$HOME_ENVIRONMENT/profile/etc/profile\"
[ -f $PROFILE_FILE ] && . $PROFILE_FILE

case $XDG_DATA_DIRS in
  *$HOME_ENVIRONMENT/profile/share*) ;;
  *) export XDG_DATA_DIRS=$HOME_ENVIRONMENT/profile/share:$XDG_DATA_DIRS ;;
esac
case $MANPATH in
  *$HOME_ENVIRONMENT/profile/share/man*) ;;
  *) export MANPATH=$HOME_ENVIRONMENT/profile/share/man:$MANPATH
esac
case $INFOPATH in
  *$HOME_ENVIRONMENT/profile/share/info*) ;;
  *) export INFOPATH=$HOME_ENVIRONMENT/profile/share/info:$INFOPATH ;;
esac
case $XDG_CONFIG_DIRS in
  *$HOME_ENVIRONMENT/profile/etc/xdg*) ;;
  *) export XDG_CONFIG_DIRS=$HOME_ENVIRONMENT/profile/etc/xdg:$XDG_CONFIG_DIRS ;;
esac
case $XCURSOR_PATH in
  *$HOME_ENVIRONMENT/profile/share/icons*) ;;
  *) export XCURSOR_PATH=$HOME_ENVIRONMENT/profile/share/icons:$XCURSOR_PATH ;;
esac

" port)
                             (display
                              #$(environment-variable-shell-definitions vars)
                              port)))))))))

(define home-environment-variables-service-type
  (service-type (name 'home-environment-variables)
                (extensions
                 (list (service-extension
                        home-service-type
                        environment-variables->setup-environment-script)))
                (compose concatenate)
                (extend append)
                (default-value '())
                (description "Set the environment variables.")))

(define (files->files-directory files)
  "Return a @code{files} directory that contains FILES."
  (define (assert-no-duplicates files)
    (let loop ((files files)
               (seen (set)))
      (match files
        (() #t)
        (((file _) rest ...)
         (when (set-contains? seen file)
           (raise (formatted-message (G_ "duplicate '~a' entry for files/")
                                     file)))
         (loop rest (set-insert file seen))))))

  ;; Detect duplicates early instead of letting them through, eventually
  ;; leading to a build failure of "files.drv".
  (assert-no-duplicates files)

  (file-union "files" files))

;; Used by symlink-manager
(define home-files-directory "files")

(define (files-entry files)
  "Return an entry for the @file{~/.guix-home/files}
directory containing FILES."
  (with-monad %store-monad
    (return `((,home-files-directory ,(files->files-directory files))))))

(define home-files-service-type
  (service-type (name 'home-files)
                (extensions
                 (list (service-extension home-service-type
                                          files-entry)))
                (compose concatenate)
                (extend append)
                (default-value '())
                (description "Files that will be put in
@file{~/.guix-home/files}, and further processed during activation.")))

(define xdg-configuration-files-directory ".config")

(define (xdg-configuration-files files)
  "Add .config/ prefix to each file-path in FILES."
  (map (match-lambda
         ((file-path . rest)
          (cons (string-append xdg-configuration-files-directory "/" file-path)
                rest)))
         files))

(define home-xdg-configuration-files-service-type
  (service-type (name 'home-xdg-configuration)
                (extensions
                 (list (service-extension home-files-service-type
                                          xdg-configuration-files)))
                (compose concatenate)
                (extend append)
                (default-value '())
                (description "Files that will be put in
@file{~/.guix-home/files/.config}, and further processed during activation.")))

(define xdg-data-files-directory ".local/share")

(define (xdg-data-files files)
  "Add .local/share prefix to each file-path in FILES."
  (map (match-lambda
         ((file-path . rest)
          (cons (string-append xdg-data-files-directory "/" file-path)
                rest)))
         files))

(define home-xdg-data-files-service-type
  (service-type (name 'home-xdg-data)
                (extensions
                 (list (service-extension home-files-service-type
                                          xdg-data-files)))
                (compose concatenate)
                (extend append)
                (default-value '())
                (description "Files that will be put in
@file{~/.guix-home/files/.local/share}, and further processed during
activation.")))


(define %initialize-gettext
  #~(begin
      (bindtextdomain %gettext-domain
                      (string-append #$guix "/share/locale"))
      (textdomain %gettext-domain)))

(define (compute-on-first-login-script _ gexps)
  (program-file
   "on-first-login"
   (with-imported-modules (source-module-closure '((guix i18n)
                                                   (guix diagnostics)))
     #~(begin
         (use-modules (guix i18n)
                      (guix diagnostics))
       #$%initialize-gettext

       (let* ((xdg-runtime-dir (or (getenv "XDG_RUNTIME_DIR")
                                   (format #f "/run/user/~a" (getuid))))
              (flag-file-path (string-append
                               xdg-runtime-dir "/on-first-login-executed"))
              (touch (lambda (file-name)
                       (call-with-output-file file-name (const #t)))))
         ;; XDG_RUNTIME_DIR dissapears on logout, that means such trick
         ;; allows to launch on-first-login script on first login only
         ;; after complete logout/reboot.
         (if (file-exists? xdg-runtime-dir)
             (unless (file-exists? flag-file-path)
               (begin #$@gexps (touch flag-file-path)))
             ;; TRANSLATORS: 'on-first-login' is the name of a service and
             ;; shouldn't be translated
             (warning (G_ "XDG_RUNTIME_DIR doesn't exists, on-first-login script
won't execute anything.  You can check if xdg runtime directory exists,
XDG_RUNTIME_DIR variable is set to appropriate value and manually execute the
script by running '$HOME/.guix-home/on-first-login'"))))))))

(define (on-first-login-script-entry on-first-login)
  "Return, as a monadic value, an entry for the on-first-login script
in the home environment directory."
  (with-monad %store-monad
    (return `(("on-first-login" ,on-first-login)))))

(define home-run-on-first-login-service-type
  (service-type (name 'home-run-on-first-login)
                (extensions
                 (list (service-extension
                        home-service-type
                        on-first-login-script-entry)))
                (compose identity)
                (extend compute-on-first-login-script)
                (default-value #f)
                (description "Run gexps on first user login.  Can be
extended with one gexp.")))


(define (compute-activation-script init-gexp gexps)
  (gexp->script
   "activate"
   #~(let* ((he-init-file (lambda (he) (string-append he "/setup-environment")))
            (he-path (string-append (getenv "HOME") "/.guix-home"))
            (new-home-env (getenv "GUIX_NEW_HOME"))
            (new-home (or new-home-env
                          ;; Absolute path of the directory of the activation
                          ;; file if called interactively.
                          (canonicalize-path (dirname (car (command-line))))))
            (old-home-env (getenv "GUIX_OLD_HOME"))
            (old-home (or old-home-env
                          (if (file-exists? (he-init-file he-path))
                              (readlink he-path)
                              #f))))
       (if (file-exists? (he-init-file new-home))
           (let* ((port   ((@ (ice-9 popen) open-input-pipe)
                           (format #f "source ~a && ~a -0"
                                   (he-init-file new-home)
                                   #$(file-append coreutils "/bin/env"))))
                  (result ((@ (ice-9 rdelim) read-delimited) "" port))
                  (vars (map (lambda (x)
                               (let ((si (string-index x #\=)))
                                 (cons (string-take x si)
                                       (string-drop x (1+ si)))))
                             ((@ (srfi srfi-1) remove)
                              string-null?
                              (string-split result #\nul)))))
             (close-port port)
             (map (lambda (x) (setenv (car x) (cdr x))) vars)

             (setenv "GUIX_NEW_HOME" new-home)
             (setenv "GUIX_OLD_HOME" old-home)

             #$@gexps

             ;; Do not unset env variable if it was set outside.
             (unless new-home-env (setenv "GUIX_NEW_HOME" #f))
             (unless old-home-env (setenv "GUIX_OLD_HOME" #f)))
           (format #t "\
Activation script was either called or loaded by file from this directory:
~a
It doesn't seem that home environment is somewhere around.
Make sure that you call ./activate by symlink from -home store item.\n"
                   new-home)))))

(define (activation-script-entry m-activation)
  "Return, as a monadic value, an entry for the activation script
in the home environment directory."
  (mlet %store-monad ((activation m-activation))
    (return `(("activate" ,activation)))))

(define home-activation-service-type
  (service-type (name 'home-activation)
                (extensions
                 (list (service-extension
                        home-service-type
                        activation-script-entry)))
                (compose identity)
                (extend compute-activation-script)
                (default-value #f)
                (description "Run gexps to activate the current
generation of home environment and update the state of the home
directory.  @command{activate} script automatically called during
reconfiguration or generation switching.  This service can be extended
with one gexp, but many times, and all gexps must be idempotent.")))


;;;
;;; On-change.
;;;

(define (compute-on-change-gexp eval-gexps? pattern-gexp-tuples)
  (with-imported-modules (source-module-closure '((guix i18n)))
    #~(begin
      (use-modules (guix i18n))

      #$%initialize-gettext

      (define (equal-regulars? file1 file2)
        "Check if FILE1 and FILE2 are bit for bit identical."
        (let* ((cmp-binary #$(file-append
                              (@ (gnu packages base) diffutils) "/bin/cmp"))
               (stats1     (lstat file1))
               (stats2     (lstat file2)))
          (cond
           ((= (stat:ino stats1) (stat:ino stats2))         #t)
           ((not (= (stat:size stats1) (stat:size stats2))) #f)

           (else (= (system* cmp-binary file1 file2) 0)))))

      (define (equal-symlinks? symlink1 symlink2)
        "Check if SYMLINK1 and SYMLINK2 are pointing to the same target."
        (string=? (readlink symlink1) (readlink symlink2)))

      (define (equal-directories? dir1 dir2)
        "Check if DIR1 and DIR2 have the same content."
        (define (ordinary-file file)
          (not (or (string=? file ".")
                   (string=? file ".."))))
        (let* ((files1 (scandir dir1 ordinary-file))
               (files2 (scandir dir2 ordinary-file)))
          (if (equal? files1 files2)
              (map (lambda (file)
                     (equal-files?
                      (string-append dir1 "/" file)
                      (string-append dir2 "/" file)))
                   files1)
              #f)))

      (define (equal-files? file1 file2)
        "Compares files, symlinks or directories of the same type."
        (case (file-type file1)
          ((directory) (equal-directories? file1 file2))
          ((symlink) (equal-symlinks? file1 file2))
          ((regular) (equal-regulars? file1 file2))
          (else
           (display "The file type is unsupported by on-change service.\n")
           #f)))

      (define (file-type file)
        (stat:type (lstat file)))

      (define (something-changed? file1 file2)
        (cond
         ((and (not (file-exists? file1))
               (not (file-exists? file2))) #f)
         ((or  (not (file-exists? file1))
               (not (file-exists? file2))) #t)

         ((not (eq? (file-type file1) (file-type file2))) #t)

         (else
          (not (equal-files? file1 file2)))))

      (define expressions-to-eval
        (map
         (lambda (x)
           (let* ((file1 (string-append
                          (or (getenv "GUIX_OLD_HOME")
                              "/gnu/store/non-existing-generation")
                          "/" (car x)))
                  (file2 (string-append (getenv "GUIX_NEW_HOME") "/" (car x)))
                  (_ (format #t (G_ "Comparing ~a and\n~10t~a...") file1 file2))
                  (any-changes? (something-changed? file1 file2))
                  (_ (format #t (G_ " done (~a)\n")
                             (if any-changes? "changed" "same"))))
             (if any-changes? (cadr x) "")))
         '#$pattern-gexp-tuples))

      (if #$eval-gexps?
          (begin
            ;;; TRANSLATORS: 'on-change' is the name of a service type, it
            ;;; probably shouldn't be translated.
            (display (G_ "Evaluating on-change gexps.\n\n"))
            (for-each primitive-eval expressions-to-eval)
            (display (G_ "On-change gexps evaluation finished.\n\n")))
          (display "\
On-change gexps won't be evaluated; evaluation has been disabled in the
service configuration")))))

(define home-run-on-change-service-type
  (service-type (name 'home-run-on-change)
                (extensions
                 (list (service-extension
                        home-activation-service-type
                        identity)))
                (compose concatenate)
                (extend compute-on-change-gexp)
                (default-value #t)
                (description "\
G-expressions to run if the specified files have changed since the
last generation.  The extension should be a list of lists where the
first element is the pattern for file or directory that expected to be
changed, and the second element is the G-expression to be evaluated.")))


;;;
;;; Provenance tracking.
;;;

(define home-provenance-service-type
  (service-type
   (name 'home-provenance)
   (extensions
    (list (service-extension
           home-service-type
           (service-extension-compute
            (first (service-type-extensions provenance-service-type))))))
   (default-value #f)                ;the HE config file
   (description "\
Store provenance information about the home environment in the home
environment itself: the channels used when building the home
environment, and its configuration file, when available.")))

(define sexp->home-provenance sexp->system-provenance)
(define home-provenance system-provenance)


;;;
;;; Searching
;;;

(define (parent-directory directory)
  "Get the parent directory of DIRECTORY"
  (string-join (drop-right (string-split directory #\/) 1) "/"))

(define %guix-home-root-directory
  ;; Absolute file name of the module hierarchy.
  (parent-directory
   (dirname (dirname (search-path %load-path "gnu/home/services.scm")))))

(define %service-type-path
  ;; Search path for service types.
  (make-parameter `((,%guix-home-root-directory . "gnu/home/services"))))

(define (all-home-service-modules)
  "Return the default set of `home service' modules."
  (cons (resolve-interface '(gnu home services))
        (all-modules (%service-type-path)
                     #:warn warn-about-load-error)))

(define* (fold-home-service-types proc seed)
  (fold-service-types proc seed (all-home-service-modules)))

(define lookup-home-service-types
  (let ((table
         (delay (fold-home-service-types (lambda (type result)
                                           (vhash-consq (service-type-name type)
                                                        type result))
                                         vlist-null))))
    (lambda (name)
      "Return the list of services with the given NAME (a symbol)."
      (vhash-foldq* cons '() name (force table)))))