1 ;;; GNU Guix --- Functional package management for GNU
2 ;;; Copyright © 2016, 2017, 2018, 2019 Ludovic Courtès <ludo@gnu.org>
4 ;;; This file is part of GNU Guix.
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.
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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.
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/>.
19 (define-module (gnu services mcron)
20 #:use-module (gnu services)
21 #:use-module (gnu services shepherd)
22 #:autoload (gnu packages guile-xyz) (mcron)
23 #:use-module (guix deprecation)
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
31 mcron-configuration-mcron
32 mcron-configuration-jobs
39 ;;; This module implements a service that to run instances of GNU mcron, a
40 ;;; periodic job execution daemon. Example of a service:
42 ;; (service mcron-service-type
43 ;; (mcron-configuration
44 ;; (jobs (list #~(job next-second-from
46 ;; (call-with-output-file "/dev/console"
48 ;; (display "hello!\n" port)))))))))
52 (define-record-type* <mcron-configuration> mcron-configuration
53 make-mcron-configuration
55 (mcron mcron-configuration-mcron ;package
57 (jobs mcron-configuration-jobs ;list of <mcron-job>
60 (define (job-file job)
61 (scheme-file "mcron-job" job))
63 (define (shepherd-schedule-action mcron files)
64 "Return a Shepherd action that runs MCRON with '--schedule' for the given
69 "Display jobs that are going to be scheduled.")
71 #~(lambda* (_ #:optional (n "5"))
72 ;; XXX: This is a global side effect.
73 (setenv "GUILE_AUTO_COMPILE" "0")
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
78 (let ((pipe (open-pipe* OPEN_READ
79 #$(file-append mcron "/bin/mcron")
80 (string-append "--schedule=" n)
83 (match (read-line pipe 'concat)
87 (zero? (close-pipe pipe)))
89 ;; There's a race with the SIGCHLD handler, which
90 ;; could call 'waitpid' before 'close-pipe' above does. If
91 ;; we get ECHILD, that means we lost the race, but that's
93 (or (= ECHILD (system-error-errno args))
94 (apply throw args)))))
99 (define mcron-shepherd-services
101 (($ <mcron-configuration> mcron ()) ;nothing to do!
103 (($ <mcron-configuration> mcron jobs)
104 (let ((files (map job-file jobs)))
105 (list (shepherd-service
107 (requirement '(user-processes))
108 (modules `((srfi srfi-1)
110 (ice-9 popen) ;for the 'schedule' action
114 (start #~(make-forkexec-constructor
115 (list (string-append #$mcron "/bin/mcron") #$@files)
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=" <>)
125 #:log-file "/var/log/mcron.log"))
126 (stop #~(make-kill-destructor))
129 (list (shepherd-schedule-action mcron files)))))))))
131 (define mcron-service-type
132 (service-type (name 'mcron)
134 "Run the mcron job scheduling daemon.")
136 (list (service-extension shepherd-root-service-type
137 mcron-shepherd-services)
138 (service-extension profile-service-type
140 mcron-configuration-mcron))))
141 (compose concatenate)
142 (extend (lambda (config jobs)
145 (jobs (append (mcron-configuration-jobs config)
147 (default-value (mcron-configuration)))) ;empty job list
149 (define-deprecated (mcron-service jobs #:optional (mcron mcron))
151 "Return an mcron service running @var{mcron} that schedules @var{jobs}, a
152 list of gexps denoting mcron job specifications.
154 This is a shorthand for:
156 (service mcron-service-type
157 (mcron-configuration (mcron mcron) (jobs jobs)))
160 (service mcron-service-type
161 (mcron-configuration (mcron mcron) (jobs jobs))))
163 ;;; mcron.scm ends here