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db4fdc04 | 1 | ;;; GNU Guix --- Functional package management for GNU |
8b9cad01 | 2 | ;;; Copyright © 2013, 2014, 2015, 2016, 2018, 2019, 2020 Ludovic Courtès <ludo@gnu.org> |
750a4239 | 3 | ;;; Copyright © 2017 Clément Lassieur <clement@lassieur.org> |
4245ddcb | 4 | ;;; Copyright © 2018 Carlo Zancanaro <carlo@zancanaro.id.au> |
d2fc7646 | 5 | ;;; Copyright © 2020 Jan (janneke) Nieuwenhuizen <janneke@gnu.org> |
db4fdc04 LC |
6 | ;;; |
7 | ;;; This file is part of GNU Guix. | |
8 | ;;; | |
9 | ;;; GNU Guix is free software; you can redistribute it and/or modify it | |
10 | ;;; under the terms of the GNU General Public License as published by | |
11 | ;;; the Free Software Foundation; either version 3 of the License, or (at | |
12 | ;;; your option) any later version. | |
13 | ;;; | |
14 | ;;; GNU Guix is distributed in the hope that it will be useful, but | |
15 | ;;; WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | ;;; GNU General Public License for more details. | |
18 | ;;; | |
19 | ;;; You should have received a copy of the GNU General Public License | |
20 | ;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>. | |
21 | ||
0190c1c0 | 22 | (define-module (gnu services shepherd) |
116244df LC |
23 | #:use-module (guix ui) |
24 | #:use-module (guix sets) | |
b5f4e686 | 25 | #:use-module (guix gexp) |
e87f0591 | 26 | #:use-module (guix store) |
0adfe95a | 27 | #:use-module (guix records) |
e87f0591 | 28 | #:use-module (guix derivations) ;imported-modules, etc. |
d2fc7646 | 29 | #:use-module (guix utils) |
db4fdc04 | 30 | #:use-module (gnu services) |
7b44cae5 | 31 | #:use-module (gnu services herd) |
0adfe95a | 32 | #:use-module (gnu packages admin) |
db4fdc04 | 33 | #:use-module (ice-9 match) |
80a67734 | 34 | #:use-module (ice-9 vlist) |
db4fdc04 | 35 | #:use-module (srfi srfi-1) |
80a67734 | 36 | #:use-module (srfi srfi-26) |
116244df LC |
37 | #:use-module (srfi srfi-34) |
38 | #:use-module (srfi srfi-35) | |
d4053c71 AK |
39 | #:export (shepherd-root-service-type |
40 | %shepherd-root-service | |
41 | shepherd-service-type | |
42 | ||
43 | shepherd-service | |
44 | shepherd-service? | |
45 | shepherd-service-documentation | |
46 | shepherd-service-provision | |
240b57f0 | 47 | shepherd-service-canonical-name |
d4053c71 | 48 | shepherd-service-requirement |
95ef8b85 | 49 | shepherd-service-one-shot? |
d4053c71 AK |
50 | shepherd-service-respawn? |
51 | shepherd-service-start | |
52 | shepherd-service-stop | |
53 | shepherd-service-auto-start? | |
54 | shepherd-service-modules | |
fae685b9 | 55 | |
70138308 LC |
56 | shepherd-action |
57 | shepherd-action? | |
58 | shepherd-action-name | |
59 | shepherd-action-documentation | |
60 | shepherd-action-procedure | |
61 | ||
fae685b9 | 62 | %default-modules |
80a67734 | 63 | |
240b57f0 LC |
64 | shepherd-service-file |
65 | ||
a5d78eb6 | 66 | shepherd-service-lookup-procedure |
7b44cae5 | 67 | shepherd-service-back-edges |
10c41368 LC |
68 | shepherd-service-upgrade |
69 | ||
70 | user-processes-service-type)) | |
db4fdc04 LC |
71 | |
72 | ;;; Commentary: | |
73 | ;;; | |
fe1ad5f5 | 74 | ;;; Instantiating system services as a shepherd configuration file. |
db4fdc04 LC |
75 | ;;; |
76 | ;;; Code: | |
77 | ||
0adfe95a | 78 | |
d4053c71 | 79 | (define (shepherd-boot-gexp services) |
378daa8c LC |
80 | #~(begin |
81 | ;; Keep track of the booted system. | |
82 | (false-if-exception (delete-file "/run/booted-system")) | |
83 | (symlink (readlink "/run/current-system") | |
84 | "/run/booted-system") | |
0adfe95a | 85 | |
378daa8c LC |
86 | ;; Close any remaining open file descriptors to be on the safe |
87 | ;; side. This must be the very last thing we do, because | |
88 | ;; Guile has internal FDs such as 'sleep_pipe' that need to be | |
89 | ;; alive. | |
90 | (let loop ((fd 3)) | |
91 | (when (< fd 1024) | |
92 | (false-if-exception (close-fdes fd)) | |
93 | (loop (+ 1 fd)))) | |
0adfe95a | 94 | |
378daa8c LC |
95 | ;; Start shepherd. |
96 | (execl #$(file-append shepherd "/bin/shepherd") | |
97 | "shepherd" "--config" | |
98 | #$(shepherd-configuration-file services)))) | |
0adfe95a | 99 | |
d4053c71 | 100 | (define shepherd-root-service-type |
0adfe95a | 101 | (service-type |
d4053c71 AK |
102 | (name 'shepherd-root) |
103 | ;; Extending the root shepherd service (aka. PID 1) happens by | |
104 | ;; concatenating the list of services provided by the extensions. | |
0adfe95a LC |
105 | (compose concatenate) |
106 | (extend append) | |
d4053c71 AK |
107 | (extensions (list (service-extension boot-service-type |
108 | shepherd-boot-gexp) | |
c273d81b | 109 | (service-extension profile-service-type |
dd0804c6 LC |
110 | (const (list shepherd))))) |
111 | (description | |
112 | "Run the GNU Shepherd as PID 1---i.e., the operating system's first | |
113 | process. The Shepherd takes care of managing services such as daemons by | |
114 | ensuring they are started and stopped in the right order."))) | |
0adfe95a | 115 | |
d4053c71 AK |
116 | (define %shepherd-root-service |
117 | ;; The root shepherd service, aka. PID 1. Its parameter is a list of | |
118 | ;; <shepherd-service> objects. | |
119 | (service shepherd-root-service-type '())) | |
0adfe95a | 120 | |
88cd7bbd LC |
121 | (define-syntax shepherd-service-type |
122 | (syntax-rules () | |
123 | "Return a <service-type> denoting a simple shepherd service--i.e., the type | |
124 | for a service that extends SHEPHERD-ROOT-SERVICE-TYPE and nothing else. When | |
125 | DEFAULT is given, use it as the service's default value." | |
126 | ((_ service-name proc default) | |
127 | (service-type | |
128 | (name service-name) | |
129 | (extensions | |
130 | (list (service-extension shepherd-root-service-type | |
131 | (compose list proc)))) | |
132 | (default-value default))) | |
133 | ((_ service-name proc) | |
134 | (service-type | |
135 | (name service-name) | |
136 | (extensions | |
137 | (list (service-extension shepherd-root-service-type | |
138 | (compose list proc)))))))) | |
0adfe95a | 139 | |
fae685b9 LC |
140 | (define %default-imported-modules |
141 | ;; Default set of modules imported for a service's consumption. | |
142 | '((guix build utils) | |
479b417b | 143 | (guix build syscalls))) |
fae685b9 LC |
144 | |
145 | (define %default-modules | |
146 | ;; Default set of modules visible in a service's file. | |
34044d55 | 147 | `((shepherd service) |
fae685b9 | 148 | (oop goops) |
408ae72c | 149 | ((guix build utils) #:hide (delete)) |
479b417b | 150 | (guix build syscalls))) |
fae685b9 | 151 | |
d4053c71 AK |
152 | (define-record-type* <shepherd-service> |
153 | shepherd-service make-shepherd-service | |
154 | shepherd-service? | |
155 | (documentation shepherd-service-documentation ;string | |
0adfe95a | 156 | (default "[No documentation.]")) |
d4053c71 AK |
157 | (provision shepherd-service-provision) ;list of symbols |
158 | (requirement shepherd-service-requirement ;list of symbols | |
0adfe95a | 159 | (default '())) |
95ef8b85 LC |
160 | (one-shot? shepherd-service-one-shot? ;Boolean |
161 | (default #f)) | |
d4053c71 | 162 | (respawn? shepherd-service-respawn? ;Boolean |
0adfe95a | 163 | (default #t)) |
d4053c71 AK |
164 | (start shepherd-service-start) ;g-expression (procedure) |
165 | (stop shepherd-service-stop ;g-expression (procedure) | |
0adfe95a | 166 | (default #~(const #f))) |
70138308 LC |
167 | (actions shepherd-service-actions ;list of <shepherd-action> |
168 | (default '())) | |
d4053c71 | 169 | (auto-start? shepherd-service-auto-start? ;Boolean |
fae685b9 | 170 | (default #t)) |
d4053c71 | 171 | (modules shepherd-service-modules ;list of module names |
a91c3fc7 | 172 | (default %default-modules))) |
0adfe95a | 173 | |
70138308 LC |
174 | (define-record-type* <shepherd-action> |
175 | shepherd-action make-shepherd-action | |
176 | shepherd-action? | |
177 | (name shepherd-action-name) ;symbol | |
178 | (procedure shepherd-action-procedure) ;gexp | |
179 | (documentation shepherd-action-documentation)) ;string | |
180 | ||
240b57f0 LC |
181 | (define (shepherd-service-canonical-name service) |
182 | "Return the 'canonical name' of SERVICE." | |
183 | (first (shepherd-service-provision service))) | |
0adfe95a | 184 | |
2d2651e7 | 185 | (define (assert-valid-graph services) |
d4053c71 AK |
186 | "Raise an error if SERVICES does not define a valid shepherd service graph, |
187 | for instance if a service requires a nonexistent service, or if more than one | |
2d2651e7 | 188 | service uses a given name. |
116244df | 189 | |
d4053c71 AK |
190 | These are constraints that shepherd's 'register-service' verifies but we'd |
191 | better verify them here statically than wait until PID 1 halts with an | |
192 | assertion failure." | |
2d2651e7 LC |
193 | (define provisions |
194 | ;; The set of provisions (symbols). Bail out if a symbol is given more | |
195 | ;; than once. | |
196 | (fold (lambda (service set) | |
197 | (define (assert-unique symbol) | |
198 | (when (set-contains? set symbol) | |
199 | (raise (condition | |
200 | (&message | |
201 | (message | |
69daee23 | 202 | (format #f (G_ "service '~a' provided more than once") |
2d2651e7 LC |
203 | symbol))))))) |
204 | ||
d4053c71 AK |
205 | (for-each assert-unique (shepherd-service-provision service)) |
206 | (fold set-insert set (shepherd-service-provision service))) | |
207 | (setq 'shepherd) | |
2d2651e7 LC |
208 | services)) |
209 | ||
210 | (define (assert-satisfied-requirements service) | |
211 | ;; Bail out if the requirements of SERVICE aren't satisfied. | |
212 | (for-each (lambda (requirement) | |
213 | (unless (set-contains? provisions requirement) | |
214 | (raise (condition | |
215 | (&message | |
216 | (message | |
69daee23 | 217 | (format #f (G_ "service '~a' requires '~a', \ |
2c2ec261 | 218 | which is not provided by any service") |
d4053c71 | 219 | (match (shepherd-service-provision service) |
2d2651e7 LC |
220 | ((head . _) head) |
221 | (_ service)) | |
222 | requirement))))))) | |
d4053c71 | 223 | (shepherd-service-requirement service))) |
2d2651e7 LC |
224 | |
225 | (for-each assert-satisfied-requirements services)) | |
116244df | 226 | |
37b98e8c LC |
227 | (define %store-characters |
228 | ;; Valid store characters; see 'checkStoreName' in the daemon. | |
229 | (string->char-set | |
230 | "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz+-._?=")) | |
231 | ||
d4053c71 | 232 | (define (shepherd-service-file-name service) |
fae685b9 LC |
233 | "Return the file name where the initialization code for SERVICE is to be |
234 | stored." | |
235 | (let ((provisions (string-join (map symbol->string | |
d4053c71 AK |
236 | (shepherd-service-provision service))))) |
237 | (string-append "shepherd-" | |
37b98e8c LC |
238 | (string-map (lambda (chr) |
239 | (if (char-set-contains? %store-characters chr) | |
240 | chr | |
241 | #\-)) | |
fae685b9 LC |
242 | provisions) |
243 | ".scm"))) | |
244 | ||
d4053c71 | 245 | (define (shepherd-service-file service) |
fae685b9 | 246 | "Return a file defining SERVICE." |
33033a62 LC |
247 | (scheme-file (shepherd-service-file-name service) |
248 | (with-imported-modules %default-imported-modules | |
249 | #~(begin | |
250 | (use-modules #$@(shepherd-service-modules service)) | |
251 | ||
252 | (make <service> | |
253 | #:docstring '#$(shepherd-service-documentation service) | |
254 | #:provides '#$(shepherd-service-provision service) | |
255 | #:requires '#$(shepherd-service-requirement service) | |
95ef8b85 LC |
256 | |
257 | ;; The 'one-shot?' slot is new in Shepherd 0.6.0. | |
258 | ;; Older versions ignore it. | |
259 | #:one-shot? '#$(shepherd-service-one-shot? service) | |
260 | ||
33033a62 LC |
261 | #:respawn? '#$(shepherd-service-respawn? service) |
262 | #:start #$(shepherd-service-start service) | |
70138308 LC |
263 | #:stop #$(shepherd-service-stop service) |
264 | #:actions | |
265 | (make-actions | |
266 | #$@(map (match-lambda | |
267 | (($ <shepherd-action> name proc doc) | |
268 | #~(#$name #$doc #$proc))) | |
269 | (shepherd-service-actions service)))))))) | |
fae685b9 | 270 | |
63b0ce39 LC |
271 | (define (scm->go file) |
272 | "Compile FILE, which contains code to be loaded by shepherd's config file, | |
273 | and return the resulting '.go' file." | |
5e9cf933 | 274 | (let-system (system target) |
d2fc7646 JN |
275 | (with-extensions (list shepherd) |
276 | (computed-file (string-append (basename (scheme-file-name file) ".scm") | |
277 | ".go") | |
278 | #~(begin | |
279 | (use-modules (system base compile) | |
280 | (system base target)) | |
281 | ||
282 | ;; Do the same as the Shepherd's 'load-in-user-module'. | |
283 | (let ((env (make-fresh-user-module))) | |
284 | (module-use! env (resolve-interface '(oop goops))) | |
285 | (module-use! env (resolve-interface '(shepherd service))) | |
286 | (with-target #$(or target #~%host-type) | |
287 | (lambda _ | |
288 | (compile-file #$file #:output-file #$output | |
289 | #:env env))))) | |
290 | ||
291 | ;; It's faster to build locally than to download. | |
292 | #:options '(#:local-build? #t | |
293 | #:substitutable? #f))))) | |
63b0ce39 | 294 | |
fe1ad5f5 AK |
295 | (define (shepherd-configuration-file services) |
296 | "Return the shepherd configuration file for SERVICES." | |
2d2651e7 | 297 | (assert-valid-graph services) |
116244df | 298 | |
33033a62 | 299 | (let ((files (map shepherd-service-file services))) |
23ed63a1 LC |
300 | (define config |
301 | #~(begin | |
081bd3bd LC |
302 | (use-modules (srfi srfi-34) |
303 | (system repl error-handling)) | |
b9c7ed71 | 304 | |
8b9cad01 LC |
305 | ;; Specify the default environment visible to all the services. |
306 | ;; Without this statement, all the environment variables of PID 1 | |
307 | ;; are inherited by child services. | |
308 | (default-environment-variables | |
309 | '("PATH=/run/current-system/profile/bin")) | |
310 | ||
8aa752ba LC |
311 | ;; Booting off a DVD, especially on a slow machine, can make |
312 | ;; everything slow. Thus, increase the timeout compared to the | |
313 | ;; default 5s in the Shepherd 0.7.0. See | |
314 | ;; <https://bugs.gnu.org/40572>. | |
e3358a83 | 315 | (default-pid-file-timeout 30) |
8aa752ba | 316 | |
234ea8a7 LC |
317 | ;; Arrange to spawn a REPL if something goes wrong. This is better |
318 | ;; than a kernel panic. | |
b9c7ed71 LC |
319 | (call-with-error-handling |
320 | (lambda () | |
63b0ce39 | 321 | (apply register-services |
408ae72c LC |
322 | (parameterize ((current-warning-port |
323 | (%make-void-port "w"))) | |
324 | (map load-compiled '#$(map scm->go files)))))) | |
63b0ce39 | 325 | |
63b0ce39 LC |
326 | (format #t "starting services...~%") |
327 | (for-each (lambda (service) | |
328 | ;; In the Shepherd 0.3 the 'start' method can raise | |
329 | ;; '&action-runtime-error' if it fails, so protect | |
330 | ;; against it. (XXX: 'action-runtime-error?' is not | |
331 | ;; exported is 0.3, hence 'service-error?'.) | |
332 | (guard (c ((service-error? c) | |
333 | (format (current-error-port) | |
334 | "failed to start service '~a'~%" | |
335 | service))) | |
336 | (start service))) | |
337 | '#$(append-map shepherd-service-provision | |
338 | (filter shepherd-service-auto-start? | |
339 | services))) | |
340 | ||
341 | ;; Hang up stdin. At this point, we assume that 'start' methods | |
342 | ;; that required user interaction on the console (e.g., | |
343 | ;; 'cryptsetup open' invocations, post-fsck emergency REPL) have | |
344 | ;; completed. User interaction becomes impossible after this | |
345 | ;; call; this avoids situations where services wrongfully lead | |
346 | ;; PID 1 to read from stdin (the console), which users may not | |
347 | ;; have access to (see <https://bugs.gnu.org/23697>). | |
348 | (redirect-port (open-input-file "/dev/null") | |
349 | (current-input-port)))) | |
23ed63a1 | 350 | |
33033a62 | 351 | (scheme-file "shepherd.conf" config))) |
db4fdc04 | 352 | |
a5d78eb6 LC |
353 | (define* (shepherd-service-lookup-procedure services |
354 | #:optional | |
355 | (provision | |
356 | shepherd-service-provision)) | |
357 | "Return a procedure that, when passed a symbol, return the item among | |
358 | SERVICES that provides this symbol. PROVISION must be a one-argument | |
359 | procedure that takes a service and returns the list of symbols it provides." | |
360 | (let ((services (fold (lambda (service result) | |
361 | (fold (cut vhash-consq <> service <>) | |
362 | result | |
363 | (provision service))) | |
364 | vlist-null | |
365 | services))) | |
366 | (lambda (name) | |
367 | (match (vhash-assq name services) | |
368 | ((_ . service) service) | |
369 | (#f #f))))) | |
370 | ||
6673bddc LC |
371 | (define* (shepherd-service-back-edges services |
372 | #:key | |
373 | (provision shepherd-service-provision) | |
374 | (requirement shepherd-service-requirement)) | |
d4053c71 | 375 | "Return a procedure that, when given a <shepherd-service> from SERVICES, |
6673bddc LC |
376 | returns the list of <shepherd-service> that depend on it. |
377 | ||
378 | Use PROVISION and REQUIREMENT as one-argument procedures that return the | |
379 | symbols provided/required by a service." | |
80a67734 | 380 | (define provision->service |
6673bddc | 381 | (shepherd-service-lookup-procedure services provision)) |
80a67734 LC |
382 | |
383 | (define edges | |
384 | (fold (lambda (service edges) | |
385 | (fold (lambda (requirement edges) | |
386 | (vhash-consq (provision->service requirement) service | |
387 | edges)) | |
388 | edges | |
6673bddc | 389 | (requirement service))) |
80a67734 LC |
390 | vlist-null |
391 | services)) | |
392 | ||
393 | (lambda (service) | |
394 | (vhash-foldq* cons '() service edges))) | |
395 | ||
7b44cae5 LC |
396 | (define (shepherd-service-upgrade live target) |
397 | "Return two values: the subset of LIVE (a list of <live-service>) that needs | |
398 | to be unloaded, and the subset of TARGET (a list of <shepherd-service>) that | |
4245ddcb | 399 | need to be restarted to complete their upgrade." |
7b44cae5 LC |
400 | (define (essential? service) |
401 | (memq (first (live-service-provision service)) | |
402 | '(root shepherd))) | |
403 | ||
404 | (define lookup-target | |
405 | (shepherd-service-lookup-procedure target | |
406 | shepherd-service-provision)) | |
407 | ||
408 | (define lookup-live | |
409 | (shepherd-service-lookup-procedure live | |
410 | live-service-provision)) | |
411 | ||
412 | (define (running? service) | |
413 | (and=> (lookup-live (shepherd-service-canonical-name service)) | |
414 | live-service-running)) | |
415 | ||
7b44cae5 LC |
416 | (define live-service-dependents |
417 | (shepherd-service-back-edges live | |
418 | #:provision live-service-provision | |
419 | #:requirement live-service-requirement)) | |
420 | ||
421 | (define (obsolete? service) | |
422 | (match (lookup-target (first (live-service-provision service))) | |
423 | (#f (every obsolete? (live-service-dependents service))) | |
424 | (_ #f))) | |
425 | ||
4245ddcb CZ |
426 | (define to-restart |
427 | ;; Restart services that are currently running. | |
428 | (filter running? target)) | |
7b44cae5 LC |
429 | |
430 | (define to-unload | |
4245ddcb CZ |
431 | ;; Unload services that are no longer required. |
432 | (remove essential? (filter obsolete? live))) | |
7b44cae5 | 433 | |
4245ddcb | 434 | (values to-unload to-restart)) |
7b44cae5 | 435 | |
10c41368 LC |
436 | \f |
437 | ;;; | |
438 | ;;; User processes. | |
439 | ;;; | |
440 | ||
441 | (define %do-not-kill-file | |
442 | ;; Name of the file listing PIDs of processes that must survive when halting | |
443 | ;; the system. Typical example is user-space file systems. | |
444 | "/etc/shepherd/do-not-kill") | |
445 | ||
446 | (define (user-processes-shepherd-service requirements) | |
447 | "Return the 'user-processes' Shepherd service with dependencies on | |
448 | REQUIREMENTS (a list of service names). | |
449 | ||
450 | This is a synchronization point used to make sure user processes and daemons | |
451 | get started only after crucial initial services have been started---file | |
452 | system mounts, etc. This is similar to the 'sysvinit' target in systemd." | |
453 | (define grace-delay | |
454 | ;; Delay after sending SIGTERM and before sending SIGKILL. | |
455 | 4) | |
456 | ||
457 | (list (shepherd-service | |
458 | (documentation "When stopped, terminate all user processes.") | |
459 | (provision '(user-processes)) | |
460 | (requirement requirements) | |
461 | (start #~(const #t)) | |
462 | (stop #~(lambda _ | |
463 | (define (kill-except omit signal) | |
464 | ;; Kill all the processes with SIGNAL except those listed | |
465 | ;; in OMIT and the current process. | |
466 | (let ((omit (cons (getpid) omit))) | |
467 | (for-each (lambda (pid) | |
468 | (unless (memv pid omit) | |
469 | (false-if-exception | |
470 | (kill pid signal)))) | |
471 | (processes)))) | |
472 | ||
473 | (define omitted-pids | |
474 | ;; List of PIDs that must not be killed. | |
475 | (if (file-exists? #$%do-not-kill-file) | |
476 | (map string->number | |
477 | (call-with-input-file #$%do-not-kill-file | |
478 | (compose string-tokenize | |
479 | (@ (ice-9 rdelim) read-string)))) | |
480 | '())) | |
481 | ||
482 | (define (now) | |
483 | (car (gettimeofday))) | |
484 | ||
485 | (define (sleep* n) | |
486 | ;; Really sleep N seconds. | |
487 | ;; Work around <http://bugs.gnu.org/19581>. | |
488 | (define start (now)) | |
489 | (let loop ((elapsed 0)) | |
490 | (when (> n elapsed) | |
491 | (sleep (- n elapsed)) | |
492 | (loop (- (now) start))))) | |
493 | ||
494 | (define lset= (@ (srfi srfi-1) lset=)) | |
495 | ||
496 | (display "sending all processes the TERM signal\n") | |
497 | ||
498 | (if (null? omitted-pids) | |
499 | (begin | |
500 | ;; Easy: terminate all of them. | |
501 | (kill -1 SIGTERM) | |
502 | (sleep* #$grace-delay) | |
503 | (kill -1 SIGKILL)) | |
504 | (begin | |
505 | ;; Kill them all except OMITTED-PIDS. XXX: We would | |
506 | ;; like to (kill -1 SIGSTOP) to get a fixed list of | |
507 | ;; processes, like 'killall5' does, but that seems | |
508 | ;; unreliable. | |
509 | (kill-except omitted-pids SIGTERM) | |
510 | (sleep* #$grace-delay) | |
511 | (kill-except omitted-pids SIGKILL) | |
512 | (delete-file #$%do-not-kill-file))) | |
513 | ||
514 | (let wait () | |
515 | ;; Reap children, if any, so that we don't end up with | |
516 | ;; zombies and enter an infinite loop. | |
517 | (let reap-children () | |
518 | (define result | |
519 | (false-if-exception | |
520 | (waitpid WAIT_ANY (if (null? omitted-pids) | |
521 | 0 | |
522 | WNOHANG)))) | |
523 | ||
524 | (when (and (pair? result) | |
525 | (not (zero? (car result)))) | |
526 | (reap-children))) | |
527 | ||
528 | (let ((pids (processes))) | |
529 | (unless (lset= = pids (cons 1 omitted-pids)) | |
530 | (format #t "waiting for process termination\ | |
531 | (processes left: ~s)~%" | |
532 | pids) | |
533 | (sleep* 2) | |
534 | (wait)))) | |
535 | ||
536 | (display "all processes have been terminated\n") | |
537 | #f)) | |
538 | (respawn? #f)))) | |
539 | ||
540 | (define user-processes-service-type | |
541 | (service-type | |
542 | (name 'user-processes) | |
543 | (extensions (list (service-extension shepherd-root-service-type | |
544 | user-processes-shepherd-service))) | |
545 | (compose concatenate) | |
546 | (extend append) | |
547 | ||
548 | ;; The value is the list of Shepherd services 'user-processes' depends on. | |
549 | ;; Extensions can add new services to this list. | |
550 | (default-value '()) | |
551 | ||
552 | (description "The @code{user-processes} service is responsible for | |
553 | terminating all the processes so that the root file system can be re-mounted | |
554 | read-only, just before rebooting/halting. Processes still running after a few | |
555 | seconds after @code{SIGTERM} has been sent are terminated with | |
556 | @code{SIGKILL}."))) | |
557 | ||
0190c1c0 | 558 | ;;; shepherd.scm ends here |