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c311089b | 1 | ;;; GNU Guix --- Functional package management for GNU |
84a2de36 | 2 | ;;; Copyright © 2016, 2017, 2018, 2019 Ludovic Courtès <ludo@gnu.org> |
c311089b 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 | ||
19 | (define-module (gnu services mcron) | |
20 | #:use-module (gnu services) | |
c311089b | 21 | #:use-module (gnu services shepherd) |
0791437f | 22 | #:autoload (gnu packages guile-xyz) (mcron) |
84a2de36 | 23 | #:use-module (guix deprecation) |
c311089b LC |
24 | #:use-module (guix records) |
25 | #:use-module (guix gexp) | |
26 | #:use-module (srfi srfi-1) | |
27 | #:use-module (ice-9 match) | |
28 | #:use-module (ice-9 vlist) | |
29 | #:export (mcron-configuration | |
30 | mcron-configuration? | |
31 | mcron-configuration-mcron | |
32 | mcron-configuration-jobs | |
33 | ||
34 | mcron-service-type | |
35 | mcron-service)) | |
36 | ||
37 | ;;; Commentary: | |
38 | ;;; | |
39 | ;;; This module implements a service that to run instances of GNU mcron, a | |
40 | ;;; periodic job execution daemon. Example of a service: | |
41 | ;; | |
42 | ;; (service mcron-service-type | |
43 | ;; (mcron-configuration | |
44 | ;; (jobs (list #~(job next-second-from | |
45 | ;; (lambda () | |
46 | ;; (call-with-output-file "/dev/console" | |
47 | ;; (lambda (port) | |
48 | ;; (display "hello!\n" port))))))))) | |
49 | ;;; | |
50 | ;;; Code: | |
51 | ||
52 | (define-record-type* <mcron-configuration> mcron-configuration | |
53 | make-mcron-configuration | |
54 | mcron-configuration? | |
55 | (mcron mcron-configuration-mcron ;package | |
cfbf6de1 | 56 | (default mcron)) |
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57 | (jobs mcron-configuration-jobs ;list of <mcron-job> |
58 | (default '()))) | |
59 | ||
60 | (define (job-file job) | |
61 | (scheme-file "mcron-job" job)) | |
62 | ||
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63 | (define (shepherd-schedule-action mcron files) |
64 | "Return a Shepherd action that runs MCRON with '--schedule' for the given | |
65 | files." | |
66 | (shepherd-action | |
67 | (name 'schedule) | |
68 | (documentation | |
69 | "Display jobs that are going to be scheduled.") | |
70 | (procedure | |
71 | #~(lambda* (_ #:optional (n "5")) | |
72 | ;; XXX: This is a global side effect. | |
73 | (setenv "GUILE_AUTO_COMPILE" "0") | |
74 | ||
75 | ;; Run 'mcron' in a pipe so we can explicitly redirect its output to | |
76 | ;; 'current-output-port', which at this stage is bound to the client | |
77 | ;; connection. | |
78 | (let ((pipe (open-pipe* OPEN_READ | |
79 | #$(file-append mcron "/bin/mcron") | |
80 | (string-append "--schedule=" n) | |
81 | #$@files))) | |
82 | (let loop () | |
83 | (match (read-line pipe 'concat) | |
84 | ((? eof-object?) | |
85 | (catch 'system-error | |
86 | (lambda () | |
87 | (zero? (close-pipe pipe))) | |
88 | (lambda args | |
19087774 | 89 | ;; There's a race with the SIGCHLD handler, which |
147c5aa5 LC |
90 | ;; could call 'waitpid' before 'close-pipe' above does. If |
91 | ;; we get ECHILD, that means we lost the race, but that's | |
92 | ;; fine. | |
93 | (or (= ECHILD (system-error-errno args)) | |
94 | (apply throw args))))) | |
95 | (line | |
96 | (display line) | |
97 | (loop))))))))) | |
98 | ||
c311089b LC |
99 | (define mcron-shepherd-services |
100 | (match-lambda | |
101 | (($ <mcron-configuration> mcron ()) ;nothing to do! | |
102 | '()) | |
103 | (($ <mcron-configuration> mcron jobs) | |
147c5aa5 LC |
104 | (let ((files (map job-file jobs))) |
105 | (list (shepherd-service | |
106 | (provision '(mcron)) | |
107 | (requirement '(user-processes)) | |
108 | (modules `((srfi srfi-1) | |
109 | (srfi srfi-26) | |
110 | (ice-9 popen) ;for the 'schedule' action | |
111 | (ice-9 rdelim) | |
112 | (ice-9 match) | |
113 | ,@%default-modules)) | |
114 | (start #~(make-forkexec-constructor | |
115 | (list (string-append #$mcron "/bin/mcron") #$@files) | |
116 | ||
117 | ;; Disable auto-compilation of the job files and set a | |
118 | ;; sane value for 'PATH'. | |
119 | #:environment-variables | |
120 | (cons* "GUILE_AUTO_COMPILE=0" | |
121 | "PATH=/run/current-system/profile/bin" | |
122 | (remove (cut string-prefix? "PATH=" <>) | |
f8cd07e8 CB |
123 | (environ))) |
124 | ||
125 | #:log-file "/var/log/mcron.log")) | |
147c5aa5 | 126 | (stop #~(make-kill-destructor)) |
c311089b | 127 | |
147c5aa5 LC |
128 | (actions |
129 | (list (shepherd-schedule-action mcron files))))))))) | |
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130 | |
131 | (define mcron-service-type | |
132 | (service-type (name 'mcron) | |
133 | (extensions | |
134 | (list (service-extension shepherd-root-service-type | |
135 | mcron-shepherd-services) | |
136 | (service-extension profile-service-type | |
137 | (compose list | |
138 | mcron-configuration-mcron)))) | |
139 | (compose concatenate) | |
140 | (extend (lambda (config jobs) | |
141 | (mcron-configuration | |
142 | (inherit config) | |
143 | (jobs (append (mcron-configuration-jobs config) | |
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144 | jobs))))) |
145 | (default-value (mcron-configuration)))) ;empty job list | |
c311089b | 146 | |
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147 | (define-deprecated (mcron-service jobs #:optional (mcron mcron)) |
148 | mcron-service-type | |
c311089b LC |
149 | "Return an mcron service running @var{mcron} that schedules @var{jobs}, a |
150 | list of gexps denoting mcron job specifications. | |
151 | ||
152 | This is a shorthand for: | |
153 | @example | |
154 | (service mcron-service-type | |
155 | (mcron-configuration (mcron mcron) (jobs jobs))) | |
156 | @end example | |
157 | " | |
158 | (service mcron-service-type | |
159 | (mcron-configuration (mcron mcron) (jobs jobs)))) | |
160 | ||
161 | ;;; mcron.scm ends here |