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db4fdc04 | 1 | ;;; GNU Guix --- Functional package management for GNU |
c273d81b | 2 | ;;; Copyright © 2013, 2014, 2015, 2016 Ludovic Courtès <ludo@gnu.org> |
db4fdc04 LC |
3 | ;;; |
4 | ;;; This file is part of GNU Guix. | |
5 | ;;; | |
6 | ;;; GNU Guix is free software; you can redistribute it and/or modify it | |
7 | ;;; under the terms of the GNU General Public License as published by | |
8 | ;;; the Free Software Foundation; either version 3 of the License, or (at | |
9 | ;;; your option) any later version. | |
10 | ;;; | |
11 | ;;; GNU Guix is distributed in the hope that it will be useful, but | |
12 | ;;; WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | ;;; GNU General Public License for more details. | |
15 | ;;; | |
16 | ;;; You should have received a copy of the GNU General Public License | |
17 | ;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>. | |
18 | ||
0190c1c0 | 19 | (define-module (gnu services shepherd) |
116244df LC |
20 | #:use-module (guix ui) |
21 | #:use-module (guix sets) | |
b5f4e686 | 22 | #:use-module (guix gexp) |
e87f0591 | 23 | #:use-module (guix store) |
db4fdc04 | 24 | #:use-module (guix monads) |
0adfe95a | 25 | #:use-module (guix records) |
e87f0591 | 26 | #:use-module (guix derivations) ;imported-modules, etc. |
db4fdc04 | 27 | #:use-module (gnu services) |
0adfe95a | 28 | #:use-module (gnu packages admin) |
db4fdc04 | 29 | #:use-module (ice-9 match) |
80a67734 | 30 | #:use-module (ice-9 vlist) |
db4fdc04 | 31 | #:use-module (srfi srfi-1) |
80a67734 | 32 | #:use-module (srfi srfi-26) |
116244df LC |
33 | #:use-module (srfi srfi-34) |
34 | #:use-module (srfi srfi-35) | |
d4053c71 AK |
35 | #:export (shepherd-root-service-type |
36 | %shepherd-root-service | |
37 | shepherd-service-type | |
38 | ||
39 | shepherd-service | |
40 | shepherd-service? | |
41 | shepherd-service-documentation | |
42 | shepherd-service-provision | |
240b57f0 | 43 | shepherd-service-canonical-name |
d4053c71 AK |
44 | shepherd-service-requirement |
45 | shepherd-service-respawn? | |
46 | shepherd-service-start | |
47 | shepherd-service-stop | |
48 | shepherd-service-auto-start? | |
49 | shepherd-service-modules | |
50 | shepherd-service-imported-modules | |
fae685b9 LC |
51 | |
52 | %default-imported-modules | |
53 | %default-modules | |
80a67734 | 54 | |
240b57f0 LC |
55 | shepherd-service-file |
56 | ||
d4053c71 | 57 | shepherd-service-back-edges)) |
db4fdc04 LC |
58 | |
59 | ;;; Commentary: | |
60 | ;;; | |
fe1ad5f5 | 61 | ;;; Instantiating system services as a shepherd configuration file. |
db4fdc04 LC |
62 | ;;; |
63 | ;;; Code: | |
64 | ||
0adfe95a | 65 | |
d4053c71 | 66 | (define (shepherd-boot-gexp services) |
fe1ad5f5 | 67 | (mlet %store-monad ((shepherd-conf (shepherd-configuration-file services))) |
0adfe95a LC |
68 | (return #~(begin |
69 | ;; Keep track of the booted system. | |
70 | (false-if-exception (delete-file "/run/booted-system")) | |
71 | (symlink (readlink "/run/current-system") | |
72 | "/run/booted-system") | |
73 | ||
74 | ;; Close any remaining open file descriptors to be on the safe | |
75 | ;; side. This must be the very last thing we do, because | |
76 | ;; Guile has internal FDs such as 'sleep_pipe' that need to be | |
77 | ;; alive. | |
78 | (let loop ((fd 3)) | |
79 | (when (< fd 1024) | |
80 | (false-if-exception (close-fdes fd)) | |
81 | (loop (+ 1 fd)))) | |
82 | ||
34044d55 AK |
83 | ;; Start shepherd. |
84 | (execl (string-append #$shepherd "/bin/shepherd") | |
fe1ad5f5 | 85 | "shepherd" "--config" #$shepherd-conf))))) |
0adfe95a | 86 | |
d4053c71 | 87 | (define shepherd-root-service-type |
0adfe95a | 88 | (service-type |
d4053c71 AK |
89 | (name 'shepherd-root) |
90 | ;; Extending the root shepherd service (aka. PID 1) happens by | |
91 | ;; concatenating the list of services provided by the extensions. | |
0adfe95a LC |
92 | (compose concatenate) |
93 | (extend append) | |
d4053c71 AK |
94 | (extensions (list (service-extension boot-service-type |
95 | shepherd-boot-gexp) | |
c273d81b | 96 | (service-extension profile-service-type |
34044d55 | 97 | (const (list shepherd))))))) |
0adfe95a | 98 | |
d4053c71 AK |
99 | (define %shepherd-root-service |
100 | ;; The root shepherd service, aka. PID 1. Its parameter is a list of | |
101 | ;; <shepherd-service> objects. | |
102 | (service shepherd-root-service-type '())) | |
0adfe95a | 103 | |
d4053c71 AK |
104 | (define-syntax-rule (shepherd-service-type service-name proc) |
105 | "Return a <service-type> denoting a simple shepherd service--i.e., the type | |
106 | for a service that extends SHEPHERD-ROOT-SERVICE-TYPE and nothing else." | |
0adfe95a | 107 | (service-type |
00184239 | 108 | (name service-name) |
0adfe95a | 109 | (extensions |
d4053c71 | 110 | (list (service-extension shepherd-root-service-type |
0adfe95a LC |
111 | (compose list proc)))))) |
112 | ||
fae685b9 LC |
113 | (define %default-imported-modules |
114 | ;; Default set of modules imported for a service's consumption. | |
115 | '((guix build utils) | |
479b417b | 116 | (guix build syscalls))) |
fae685b9 LC |
117 | |
118 | (define %default-modules | |
119 | ;; Default set of modules visible in a service's file. | |
34044d55 | 120 | `((shepherd service) |
fae685b9 | 121 | (oop goops) |
fae685b9 | 122 | (guix build utils) |
479b417b | 123 | (guix build syscalls))) |
fae685b9 | 124 | |
d4053c71 AK |
125 | (define-record-type* <shepherd-service> |
126 | shepherd-service make-shepherd-service | |
127 | shepherd-service? | |
128 | (documentation shepherd-service-documentation ;string | |
0adfe95a | 129 | (default "[No documentation.]")) |
d4053c71 AK |
130 | (provision shepherd-service-provision) ;list of symbols |
131 | (requirement shepherd-service-requirement ;list of symbols | |
0adfe95a | 132 | (default '())) |
d4053c71 | 133 | (respawn? shepherd-service-respawn? ;Boolean |
0adfe95a | 134 | (default #t)) |
d4053c71 AK |
135 | (start shepherd-service-start) ;g-expression (procedure) |
136 | (stop shepherd-service-stop ;g-expression (procedure) | |
0adfe95a | 137 | (default #~(const #f))) |
d4053c71 | 138 | (auto-start? shepherd-service-auto-start? ;Boolean |
fae685b9 | 139 | (default #t)) |
d4053c71 | 140 | (modules shepherd-service-modules ;list of module names |
fae685b9 | 141 | (default %default-modules)) |
d4053c71 | 142 | (imported-modules shepherd-service-imported-modules ;list of module names |
fae685b9 | 143 | (default %default-imported-modules))) |
0adfe95a | 144 | |
240b57f0 LC |
145 | (define (shepherd-service-canonical-name service) |
146 | "Return the 'canonical name' of SERVICE." | |
147 | (first (shepherd-service-provision service))) | |
0adfe95a | 148 | |
2d2651e7 | 149 | (define (assert-valid-graph services) |
d4053c71 AK |
150 | "Raise an error if SERVICES does not define a valid shepherd service graph, |
151 | for instance if a service requires a nonexistent service, or if more than one | |
2d2651e7 | 152 | service uses a given name. |
116244df | 153 | |
d4053c71 AK |
154 | These are constraints that shepherd's 'register-service' verifies but we'd |
155 | better verify them here statically than wait until PID 1 halts with an | |
156 | assertion failure." | |
2d2651e7 LC |
157 | (define provisions |
158 | ;; The set of provisions (symbols). Bail out if a symbol is given more | |
159 | ;; than once. | |
160 | (fold (lambda (service set) | |
161 | (define (assert-unique symbol) | |
162 | (when (set-contains? set symbol) | |
163 | (raise (condition | |
164 | (&message | |
165 | (message | |
166 | (format #f (_ "service '~a' provided more than once") | |
167 | symbol))))))) | |
168 | ||
d4053c71 AK |
169 | (for-each assert-unique (shepherd-service-provision service)) |
170 | (fold set-insert set (shepherd-service-provision service))) | |
171 | (setq 'shepherd) | |
2d2651e7 LC |
172 | services)) |
173 | ||
174 | (define (assert-satisfied-requirements service) | |
175 | ;; Bail out if the requirements of SERVICE aren't satisfied. | |
176 | (for-each (lambda (requirement) | |
177 | (unless (set-contains? provisions requirement) | |
178 | (raise (condition | |
179 | (&message | |
180 | (message | |
181 | (format #f (_ "service '~a' requires '~a', \ | |
182 | which is undefined") | |
d4053c71 | 183 | (match (shepherd-service-provision service) |
2d2651e7 LC |
184 | ((head . _) head) |
185 | (_ service)) | |
186 | requirement))))))) | |
d4053c71 | 187 | (shepherd-service-requirement service))) |
2d2651e7 LC |
188 | |
189 | (for-each assert-satisfied-requirements services)) | |
116244df | 190 | |
d4053c71 | 191 | (define (shepherd-service-file-name service) |
fae685b9 LC |
192 | "Return the file name where the initialization code for SERVICE is to be |
193 | stored." | |
194 | (let ((provisions (string-join (map symbol->string | |
d4053c71 AK |
195 | (shepherd-service-provision service))))) |
196 | (string-append "shepherd-" | |
fae685b9 LC |
197 | (string-map (match-lambda |
198 | (#\/ #\-) | |
199 | (chr chr)) | |
200 | provisions) | |
201 | ".scm"))) | |
202 | ||
d4053c71 | 203 | (define (shepherd-service-file service) |
fae685b9 | 204 | "Return a file defining SERVICE." |
d4053c71 | 205 | (gexp->file (shepherd-service-file-name service) |
fae685b9 | 206 | #~(begin |
d4053c71 | 207 | (use-modules #$@(shepherd-service-modules service)) |
fae685b9 LC |
208 | |
209 | (make <service> | |
d4053c71 AK |
210 | #:docstring '#$(shepherd-service-documentation service) |
211 | #:provides '#$(shepherd-service-provision service) | |
212 | #:requires '#$(shepherd-service-requirement service) | |
213 | #:respawn? '#$(shepherd-service-respawn? service) | |
214 | #:start #$(shepherd-service-start service) | |
215 | #:stop #$(shepherd-service-stop service))))) | |
fae685b9 | 216 | |
fe1ad5f5 AK |
217 | (define (shepherd-configuration-file services) |
218 | "Return the shepherd configuration file for SERVICES." | |
23ed63a1 | 219 | (define modules |
fae685b9 | 220 | (delete-duplicates |
d4053c71 | 221 | (append-map shepherd-service-imported-modules services))) |
23ed63a1 | 222 | |
2d2651e7 | 223 | (assert-valid-graph services) |
116244df | 224 | |
23ed63a1 | 225 | (mlet %store-monad ((modules (imported-modules modules)) |
fae685b9 | 226 | (compiled (compiled-modules modules)) |
d4053c71 AK |
227 | (files (mapm %store-monad |
228 | shepherd-service-file | |
229 | services))) | |
23ed63a1 LC |
230 | (define config |
231 | #~(begin | |
232 | (eval-when (expand load eval) | |
233 | (set! %load-path (cons #$modules %load-path)) | |
234 | (set! %load-compiled-path | |
fae685b9 LC |
235 | (cons #$compiled %load-compiled-path))) |
236 | ||
081bd3bd LC |
237 | (use-modules (srfi srfi-34) |
238 | (system repl error-handling)) | |
b9c7ed71 LC |
239 | |
240 | ;; Arrange to spawn a REPL if loading one of FILES fails. This is | |
241 | ;; better than a kernel panic. | |
242 | (call-with-error-handling | |
243 | (lambda () | |
244 | (apply register-services (map primitive-load '#$files)))) | |
23ed63a1 LC |
245 | |
246 | ;; guix-daemon 0.6 aborts if 'PATH' is undefined, so work around it. | |
b4140694 | 247 | (setenv "PATH" "/run/current-system/profile/bin") |
23ed63a1 LC |
248 | |
249 | (format #t "starting services...~%") | |
081bd3bd LC |
250 | (for-each (lambda (service) |
251 | ;; In the Shepherd 0.3 the 'start' method can raise | |
252 | ;; '&action-runtime-error' if it fails, so protect | |
253 | ;; against it. (XXX: 'action-runtime-error?' is not | |
254 | ;; exported is 0.3, hence 'service-error?'.) | |
255 | (guard (c ((service-error? c) | |
256 | (format (current-error-port) | |
257 | "failed to start service '~a'~%" | |
258 | service))) | |
259 | (start service))) | |
d4053c71 AK |
260 | '#$(append-map shepherd-service-provision |
261 | (filter shepherd-service-auto-start? | |
c5d735f7 | 262 | services))))) |
23ed63a1 | 263 | |
fe1ad5f5 | 264 | (gexp->file "shepherd.conf" config))) |
db4fdc04 | 265 | |
d4053c71 AK |
266 | (define (shepherd-service-back-edges services) |
267 | "Return a procedure that, when given a <shepherd-service> from SERVICES, | |
268 | returns the list of <shepherd-service> that depend on it." | |
80a67734 LC |
269 | (define provision->service |
270 | (let ((services (fold (lambda (service result) | |
271 | (fold (cut vhash-consq <> service <>) | |
272 | result | |
d4053c71 | 273 | (shepherd-service-provision service))) |
80a67734 LC |
274 | vlist-null |
275 | services))) | |
276 | (lambda (name) | |
277 | (match (vhash-assq name services) | |
278 | ((_ . service) service) | |
279 | (#f #f))))) | |
280 | ||
281 | (define edges | |
282 | (fold (lambda (service edges) | |
283 | (fold (lambda (requirement edges) | |
284 | (vhash-consq (provision->service requirement) service | |
285 | edges)) | |
286 | edges | |
d4053c71 | 287 | (shepherd-service-requirement service))) |
80a67734 LC |
288 | vlist-null |
289 | services)) | |
290 | ||
291 | (lambda (service) | |
292 | (vhash-foldq* cons '() service edges))) | |
293 | ||
0190c1c0 | 294 | ;;; shepherd.scm ends here |