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.
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.
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 base)
22 #:use-module (gnu services shepherd)
23 #:autoload (gnu packages guile) (mcron)
24 #:use-module (guix deprecation)
25 #:use-module (guix records)
26 #:use-module (guix gexp)
27 #:use-module (srfi srfi-1)
28 #:use-module (ice-9 match)
29 #:use-module (ice-9 vlist)
30 #:export (mcron-configuration
32 mcron-configuration-mcron
33 mcron-configuration-jobs
40 ;;; This module implements a service that to run instances of GNU mcron, a
41 ;;; periodic job execution daemon. Example of a service:
43 ;; (service mcron-service-type
44 ;; (mcron-configuration
45 ;; (jobs (list #~(job next-second-from
47 ;; (call-with-output-file "/dev/console"
49 ;; (display "hello!\n" port)))))))))
53 (define-record-type* <mcron-configuration> mcron-configuration
54 make-mcron-configuration
56 (mcron mcron-configuration-mcron ;package
58 (jobs mcron-configuration-jobs ;list of <mcron-job>
61 (define (job-file job)
62 (scheme-file "mcron-job" job))
64 (define (shepherd-schedule-action mcron files)
65 "Return a Shepherd action that runs MCRON with '--schedule' for the given
70 "Display jobs that are going to be scheduled.")
72 #~(lambda* (_ #:optional (n "5"))
73 ;; XXX: This is a global side effect.
74 (setenv "GUILE_AUTO_COMPILE" "0")
76 ;; Run 'mcron' in a pipe so we can explicitly redirect its output to
77 ;; 'current-output-port', which at this stage is bound to the client
79 (let ((pipe (open-pipe* OPEN_READ
80 #$(file-append mcron "/bin/mcron")
81 (string-append "--schedule=" n)
84 (match (read-line pipe 'concat)
88 (zero? (close-pipe pipe)))
90 ;; There's a race with the SIGCHLD handler, which
91 ;; could call 'waitpid' before 'close-pipe' above does. If
92 ;; we get ECHILD, that means we lost the race, but that's
94 (or (= ECHILD (system-error-errno args))
95 (apply throw args)))))
100 (define mcron-shepherd-services
102 (($ <mcron-configuration> mcron ()) ;nothing to do!
104 (($ <mcron-configuration> mcron jobs)
105 (let ((files (map job-file jobs)))
106 (list (shepherd-service
108 (requirement '(user-processes))
109 (modules `((srfi srfi-1)
111 (ice-9 popen) ;for the 'schedule' action
115 (start #~(make-forkexec-constructor
116 (list (string-append #$mcron "/bin/mcron") #$@files)
118 ;; Disable auto-compilation of the job files and set a
119 ;; sane value for 'PATH'.
120 #:environment-variables
121 (cons* "GUILE_AUTO_COMPILE=0"
122 "PATH=/run/current-system/profile/bin"
123 (remove (cut string-prefix? "PATH=" <>)
125 (stop #~(make-kill-destructor))
128 (list (shepherd-schedule-action mcron files)))))))))
130 (define mcron-service-type
131 (service-type (name 'mcron)
133 (list (service-extension shepherd-root-service-type
134 mcron-shepherd-services)
135 (service-extension profile-service-type
137 mcron-configuration-mcron))))
138 (compose concatenate)
139 (extend (lambda (config jobs)
142 (jobs (append (mcron-configuration-jobs config)
144 (default-value (mcron-configuration)))) ;empty job list
146 (define-deprecated (mcron-service jobs #:optional (mcron mcron))
148 "Return an mcron service running @var{mcron} that schedules @var{jobs}, a
149 list of gexps denoting mcron job specifications.
151 This is a shorthand for:
153 (service mcron-service-type
154 (mcron-configuration (mcron mcron) (jobs jobs)))
157 (service mcron-service-type
158 (mcron-configuration (mcron mcron) (jobs jobs))))
160 ;;; mcron.scm ends here