Commit | Line | Data |
---|---|---|
db4fdc04 | 1 | ;;; GNU Guix --- Functional package management for GNU |
33033a62 | 2 | ;;; Copyright © 2013, 2014, 2015, 2016, 2018 Ludovic Courtès <ludo@gnu.org> |
750a4239 | 3 | ;;; Copyright © 2017 Clément Lassieur <clement@lassieur.org> |
db4fdc04 LC |
4 | ;;; |
5 | ;;; This file is part of GNU Guix. | |
6 | ;;; | |
7 | ;;; GNU Guix is free software; you can redistribute it and/or modify it | |
8 | ;;; under the terms of the GNU General Public License as published by | |
9 | ;;; the Free Software Foundation; either version 3 of the License, or (at | |
10 | ;;; your option) any later version. | |
11 | ;;; | |
12 | ;;; GNU Guix is distributed in the hope that it will be useful, but | |
13 | ;;; WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | ;;; GNU General Public License for more details. | |
16 | ;;; | |
17 | ;;; You should have received a copy of the GNU General Public License | |
18 | ;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>. | |
19 | ||
0190c1c0 | 20 | (define-module (gnu services shepherd) |
116244df LC |
21 | #:use-module (guix ui) |
22 | #:use-module (guix sets) | |
b5f4e686 | 23 | #:use-module (guix gexp) |
e87f0591 | 24 | #:use-module (guix store) |
0adfe95a | 25 | #:use-module (guix records) |
e87f0591 | 26 | #:use-module (guix derivations) ;imported-modules, etc. |
db4fdc04 | 27 | #:use-module (gnu services) |
7b44cae5 | 28 | #:use-module (gnu services herd) |
0adfe95a | 29 | #:use-module (gnu packages admin) |
db4fdc04 | 30 | #:use-module (ice-9 match) |
80a67734 | 31 | #:use-module (ice-9 vlist) |
db4fdc04 | 32 | #:use-module (srfi srfi-1) |
80a67734 | 33 | #:use-module (srfi srfi-26) |
116244df LC |
34 | #:use-module (srfi srfi-34) |
35 | #:use-module (srfi srfi-35) | |
d4053c71 AK |
36 | #:export (shepherd-root-service-type |
37 | %shepherd-root-service | |
38 | shepherd-service-type | |
39 | ||
40 | shepherd-service | |
41 | shepherd-service? | |
42 | shepherd-service-documentation | |
43 | shepherd-service-provision | |
240b57f0 | 44 | shepherd-service-canonical-name |
d4053c71 AK |
45 | shepherd-service-requirement |
46 | shepherd-service-respawn? | |
47 | shepherd-service-start | |
48 | shepherd-service-stop | |
49 | shepherd-service-auto-start? | |
50 | shepherd-service-modules | |
fae685b9 | 51 | |
70138308 LC |
52 | shepherd-action |
53 | shepherd-action? | |
54 | shepherd-action-name | |
55 | shepherd-action-documentation | |
56 | shepherd-action-procedure | |
57 | ||
fae685b9 | 58 | %default-modules |
80a67734 | 59 | |
240b57f0 LC |
60 | shepherd-service-file |
61 | ||
a5d78eb6 | 62 | shepherd-service-lookup-procedure |
7b44cae5 LC |
63 | shepherd-service-back-edges |
64 | shepherd-service-upgrade)) | |
db4fdc04 LC |
65 | |
66 | ;;; Commentary: | |
67 | ;;; | |
fe1ad5f5 | 68 | ;;; Instantiating system services as a shepherd configuration file. |
db4fdc04 LC |
69 | ;;; |
70 | ;;; Code: | |
71 | ||
0adfe95a | 72 | |
d4053c71 | 73 | (define (shepherd-boot-gexp services) |
378daa8c LC |
74 | #~(begin |
75 | ;; Keep track of the booted system. | |
76 | (false-if-exception (delete-file "/run/booted-system")) | |
77 | (symlink (readlink "/run/current-system") | |
78 | "/run/booted-system") | |
0adfe95a | 79 | |
378daa8c LC |
80 | ;; Close any remaining open file descriptors to be on the safe |
81 | ;; side. This must be the very last thing we do, because | |
82 | ;; Guile has internal FDs such as 'sleep_pipe' that need to be | |
83 | ;; alive. | |
84 | (let loop ((fd 3)) | |
85 | (when (< fd 1024) | |
86 | (false-if-exception (close-fdes fd)) | |
87 | (loop (+ 1 fd)))) | |
0adfe95a | 88 | |
378daa8c LC |
89 | ;; Start shepherd. |
90 | (execl #$(file-append shepherd "/bin/shepherd") | |
91 | "shepherd" "--config" | |
92 | #$(shepherd-configuration-file services)))) | |
0adfe95a | 93 | |
d4053c71 | 94 | (define shepherd-root-service-type |
0adfe95a | 95 | (service-type |
d4053c71 AK |
96 | (name 'shepherd-root) |
97 | ;; Extending the root shepherd service (aka. PID 1) happens by | |
98 | ;; concatenating the list of services provided by the extensions. | |
0adfe95a LC |
99 | (compose concatenate) |
100 | (extend append) | |
d4053c71 AK |
101 | (extensions (list (service-extension boot-service-type |
102 | shepherd-boot-gexp) | |
c273d81b | 103 | (service-extension profile-service-type |
34044d55 | 104 | (const (list shepherd))))))) |
0adfe95a | 105 | |
d4053c71 AK |
106 | (define %shepherd-root-service |
107 | ;; The root shepherd service, aka. PID 1. Its parameter is a list of | |
108 | ;; <shepherd-service> objects. | |
109 | (service shepherd-root-service-type '())) | |
0adfe95a | 110 | |
88cd7bbd LC |
111 | (define-syntax shepherd-service-type |
112 | (syntax-rules () | |
113 | "Return a <service-type> denoting a simple shepherd service--i.e., the type | |
114 | for a service that extends SHEPHERD-ROOT-SERVICE-TYPE and nothing else. When | |
115 | DEFAULT is given, use it as the service's default value." | |
116 | ((_ service-name proc default) | |
117 | (service-type | |
118 | (name service-name) | |
119 | (extensions | |
120 | (list (service-extension shepherd-root-service-type | |
121 | (compose list proc)))) | |
122 | (default-value default))) | |
123 | ((_ service-name proc) | |
124 | (service-type | |
125 | (name service-name) | |
126 | (extensions | |
127 | (list (service-extension shepherd-root-service-type | |
128 | (compose list proc)))))))) | |
0adfe95a | 129 | |
fae685b9 LC |
130 | (define %default-imported-modules |
131 | ;; Default set of modules imported for a service's consumption. | |
132 | '((guix build utils) | |
479b417b | 133 | (guix build syscalls))) |
fae685b9 LC |
134 | |
135 | (define %default-modules | |
136 | ;; Default set of modules visible in a service's file. | |
34044d55 | 137 | `((shepherd service) |
fae685b9 | 138 | (oop goops) |
fae685b9 | 139 | (guix build utils) |
479b417b | 140 | (guix build syscalls))) |
fae685b9 | 141 | |
d4053c71 AK |
142 | (define-record-type* <shepherd-service> |
143 | shepherd-service make-shepherd-service | |
144 | shepherd-service? | |
145 | (documentation shepherd-service-documentation ;string | |
0adfe95a | 146 | (default "[No documentation.]")) |
d4053c71 AK |
147 | (provision shepherd-service-provision) ;list of symbols |
148 | (requirement shepherd-service-requirement ;list of symbols | |
0adfe95a | 149 | (default '())) |
d4053c71 | 150 | (respawn? shepherd-service-respawn? ;Boolean |
0adfe95a | 151 | (default #t)) |
d4053c71 AK |
152 | (start shepherd-service-start) ;g-expression (procedure) |
153 | (stop shepherd-service-stop ;g-expression (procedure) | |
0adfe95a | 154 | (default #~(const #f))) |
70138308 LC |
155 | (actions shepherd-service-actions ;list of <shepherd-action> |
156 | (default '())) | |
d4053c71 | 157 | (auto-start? shepherd-service-auto-start? ;Boolean |
fae685b9 | 158 | (default #t)) |
d4053c71 | 159 | (modules shepherd-service-modules ;list of module names |
a91c3fc7 | 160 | (default %default-modules))) |
0adfe95a | 161 | |
70138308 LC |
162 | (define-record-type* <shepherd-action> |
163 | shepherd-action make-shepherd-action | |
164 | shepherd-action? | |
165 | (name shepherd-action-name) ;symbol | |
166 | (procedure shepherd-action-procedure) ;gexp | |
167 | (documentation shepherd-action-documentation)) ;string | |
168 | ||
240b57f0 LC |
169 | (define (shepherd-service-canonical-name service) |
170 | "Return the 'canonical name' of SERVICE." | |
171 | (first (shepherd-service-provision service))) | |
0adfe95a | 172 | |
2d2651e7 | 173 | (define (assert-valid-graph services) |
d4053c71 AK |
174 | "Raise an error if SERVICES does not define a valid shepherd service graph, |
175 | for instance if a service requires a nonexistent service, or if more than one | |
2d2651e7 | 176 | service uses a given name. |
116244df | 177 | |
d4053c71 AK |
178 | These are constraints that shepherd's 'register-service' verifies but we'd |
179 | better verify them here statically than wait until PID 1 halts with an | |
180 | assertion failure." | |
2d2651e7 LC |
181 | (define provisions |
182 | ;; The set of provisions (symbols). Bail out if a symbol is given more | |
183 | ;; than once. | |
184 | (fold (lambda (service set) | |
185 | (define (assert-unique symbol) | |
186 | (when (set-contains? set symbol) | |
187 | (raise (condition | |
188 | (&message | |
189 | (message | |
69daee23 | 190 | (format #f (G_ "service '~a' provided more than once") |
2d2651e7 LC |
191 | symbol))))))) |
192 | ||
d4053c71 AK |
193 | (for-each assert-unique (shepherd-service-provision service)) |
194 | (fold set-insert set (shepherd-service-provision service))) | |
195 | (setq 'shepherd) | |
2d2651e7 LC |
196 | services)) |
197 | ||
198 | (define (assert-satisfied-requirements service) | |
199 | ;; Bail out if the requirements of SERVICE aren't satisfied. | |
200 | (for-each (lambda (requirement) | |
201 | (unless (set-contains? provisions requirement) | |
202 | (raise (condition | |
203 | (&message | |
204 | (message | |
69daee23 | 205 | (format #f (G_ "service '~a' requires '~a', \ |
2c2ec261 | 206 | which is not provided by any service") |
d4053c71 | 207 | (match (shepherd-service-provision service) |
2d2651e7 LC |
208 | ((head . _) head) |
209 | (_ service)) | |
210 | requirement))))))) | |
d4053c71 | 211 | (shepherd-service-requirement service))) |
2d2651e7 LC |
212 | |
213 | (for-each assert-satisfied-requirements services)) | |
116244df | 214 | |
d4053c71 | 215 | (define (shepherd-service-file-name service) |
fae685b9 LC |
216 | "Return the file name where the initialization code for SERVICE is to be |
217 | stored." | |
218 | (let ((provisions (string-join (map symbol->string | |
d4053c71 AK |
219 | (shepherd-service-provision service))))) |
220 | (string-append "shepherd-" | |
fae685b9 LC |
221 | (string-map (match-lambda |
222 | (#\/ #\-) | |
750a4239 | 223 | (#\ #\-) |
fae685b9 LC |
224 | (chr chr)) |
225 | provisions) | |
226 | ".scm"))) | |
227 | ||
d4053c71 | 228 | (define (shepherd-service-file service) |
fae685b9 | 229 | "Return a file defining SERVICE." |
33033a62 LC |
230 | (scheme-file (shepherd-service-file-name service) |
231 | (with-imported-modules %default-imported-modules | |
232 | #~(begin | |
233 | (use-modules #$@(shepherd-service-modules service)) | |
234 | ||
235 | (make <service> | |
236 | #:docstring '#$(shepherd-service-documentation service) | |
237 | #:provides '#$(shepherd-service-provision service) | |
238 | #:requires '#$(shepherd-service-requirement service) | |
239 | #:respawn? '#$(shepherd-service-respawn? service) | |
240 | #:start #$(shepherd-service-start service) | |
70138308 LC |
241 | #:stop #$(shepherd-service-stop service) |
242 | #:actions | |
243 | (make-actions | |
244 | #$@(map (match-lambda | |
245 | (($ <shepherd-action> name proc doc) | |
246 | #~(#$name #$doc #$proc))) | |
247 | (shepherd-service-actions service)))))))) | |
fae685b9 | 248 | |
fe1ad5f5 AK |
249 | (define (shepherd-configuration-file services) |
250 | "Return the shepherd configuration file for SERVICES." | |
2d2651e7 | 251 | (assert-valid-graph services) |
116244df | 252 | |
33033a62 | 253 | (let ((files (map shepherd-service-file services))) |
23ed63a1 LC |
254 | (define config |
255 | #~(begin | |
081bd3bd LC |
256 | (use-modules (srfi srfi-34) |
257 | (system repl error-handling)) | |
b9c7ed71 | 258 | |
234ea8a7 LC |
259 | ;; Arrange to spawn a REPL if something goes wrong. This is better |
260 | ;; than a kernel panic. | |
b9c7ed71 LC |
261 | (call-with-error-handling |
262 | (lambda () | |
234ea8a7 LC |
263 | (apply register-services (map primitive-load '#$files)) |
264 | ||
265 | ;; guix-daemon 0.6 aborts if 'PATH' is undefined, so work around | |
266 | ;; it. | |
267 | (setenv "PATH" "/run/current-system/profile/bin") | |
268 | ||
269 | (format #t "starting services...~%") | |
270 | (for-each (lambda (service) | |
271 | ;; In the Shepherd 0.3 the 'start' method can raise | |
272 | ;; '&action-runtime-error' if it fails, so protect | |
273 | ;; against it. (XXX: 'action-runtime-error?' is not | |
274 | ;; exported is 0.3, hence 'service-error?'.) | |
275 | (guard (c ((service-error? c) | |
276 | (format (current-error-port) | |
277 | "failed to start service '~a'~%" | |
278 | service))) | |
279 | (start service))) | |
280 | '#$(append-map shepherd-service-provision | |
281 | (filter shepherd-service-auto-start? | |
282 | services))))))) | |
23ed63a1 | 283 | |
33033a62 | 284 | (scheme-file "shepherd.conf" config))) |
db4fdc04 | 285 | |
a5d78eb6 LC |
286 | (define* (shepherd-service-lookup-procedure services |
287 | #:optional | |
288 | (provision | |
289 | shepherd-service-provision)) | |
290 | "Return a procedure that, when passed a symbol, return the item among | |
291 | SERVICES that provides this symbol. PROVISION must be a one-argument | |
292 | procedure that takes a service and returns the list of symbols it provides." | |
293 | (let ((services (fold (lambda (service result) | |
294 | (fold (cut vhash-consq <> service <>) | |
295 | result | |
296 | (provision service))) | |
297 | vlist-null | |
298 | services))) | |
299 | (lambda (name) | |
300 | (match (vhash-assq name services) | |
301 | ((_ . service) service) | |
302 | (#f #f))))) | |
303 | ||
6673bddc LC |
304 | (define* (shepherd-service-back-edges services |
305 | #:key | |
306 | (provision shepherd-service-provision) | |
307 | (requirement shepherd-service-requirement)) | |
d4053c71 | 308 | "Return a procedure that, when given a <shepherd-service> from SERVICES, |
6673bddc LC |
309 | returns the list of <shepherd-service> that depend on it. |
310 | ||
311 | Use PROVISION and REQUIREMENT as one-argument procedures that return the | |
312 | symbols provided/required by a service." | |
80a67734 | 313 | (define provision->service |
6673bddc | 314 | (shepherd-service-lookup-procedure services provision)) |
80a67734 LC |
315 | |
316 | (define edges | |
317 | (fold (lambda (service edges) | |
318 | (fold (lambda (requirement edges) | |
319 | (vhash-consq (provision->service requirement) service | |
320 | edges)) | |
321 | edges | |
6673bddc | 322 | (requirement service))) |
80a67734 LC |
323 | vlist-null |
324 | services)) | |
325 | ||
326 | (lambda (service) | |
327 | (vhash-foldq* cons '() service edges))) | |
328 | ||
7b44cae5 LC |
329 | (define (shepherd-service-upgrade live target) |
330 | "Return two values: the subset of LIVE (a list of <live-service>) that needs | |
331 | to be unloaded, and the subset of TARGET (a list of <shepherd-service>) that | |
332 | needs to be loaded." | |
333 | (define (essential? service) | |
334 | (memq (first (live-service-provision service)) | |
335 | '(root shepherd))) | |
336 | ||
337 | (define lookup-target | |
338 | (shepherd-service-lookup-procedure target | |
339 | shepherd-service-provision)) | |
340 | ||
341 | (define lookup-live | |
342 | (shepherd-service-lookup-procedure live | |
343 | live-service-provision)) | |
344 | ||
345 | (define (running? service) | |
346 | (and=> (lookup-live (shepherd-service-canonical-name service)) | |
347 | live-service-running)) | |
348 | ||
349 | (define (stopped service) | |
350 | (match (lookup-live (shepherd-service-canonical-name service)) | |
351 | (#f #f) | |
352 | (service (and (not (live-service-running service)) | |
353 | service)))) | |
354 | ||
355 | (define live-service-dependents | |
356 | (shepherd-service-back-edges live | |
357 | #:provision live-service-provision | |
358 | #:requirement live-service-requirement)) | |
359 | ||
360 | (define (obsolete? service) | |
361 | (match (lookup-target (first (live-service-provision service))) | |
362 | (#f (every obsolete? (live-service-dependents service))) | |
363 | (_ #f))) | |
364 | ||
365 | (define to-load | |
366 | ;; Only load services that are either new or currently stopped. | |
367 | (remove running? target)) | |
368 | ||
369 | (define to-unload | |
370 | ;; Unload services that are (1) no longer required, or (2) are in TO-LOAD. | |
371 | (remove essential? | |
372 | (append (filter obsolete? live) | |
373 | (filter-map stopped to-load)))) | |
374 | ||
375 | (values to-unload to-load)) | |
376 | ||
0190c1c0 | 377 | ;;; shepherd.scm ends here |