From 7afbcbcd0e00d2db26f139363be81ca26a61095f Mon Sep 17 00:00:00 2001 From: Robert Vollmert Date: Fri, 29 Nov 2019 19:07:22 +0100 Subject: [PATCH] services: Add scron. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit It's a simple replacement for the mcron service. If you have a mcron job definition like (define cron-job #~(job "*/15 * * * *" #$(program-file ...))) you can convert it into the valid scron job (define cron-job (scron-job (schedule "/15 * * * *") (program-file ...))) * gnu/services/scron.scm: New file. * gnu/local.mk: Add it. * gnu/tests/base.scm (%scron-os): New variable. (run-scron-test): New procedure. (%test-scron): New variable. * doc/guix.texi: Add documentation for scron-service. Signed-off-by: Ludovic Courtès --- doc/guix.texi | 77 +++++++++++++++++++++++++++++- gnu/local.mk | 1 + gnu/services/scron.scm | 103 +++++++++++++++++++++++++++++++++++++++++ gnu/tests/base.scm | 86 ++++++++++++++++++++++++++++++++++ 4 files changed, 266 insertions(+), 1 deletion(-) create mode 100644 gnu/services/scron.scm diff --git a/doc/guix.texi b/doc/guix.texi index 446534c576..0fa8a9bd01 100644 --- a/doc/guix.texi +++ b/doc/guix.texi @@ -282,7 +282,7 @@ System Configuration Services * Base Services:: Essential system services. -* Scheduled Job Execution:: The mcron service. +* Scheduled Job Execution:: Cron services. * Log Rotation:: The rottlog service. * Networking Services:: Network setup, SSH daemon, etc. * X Window:: Graphical display. @@ -12899,6 +12899,81 @@ specifications,, mcron, GNU@tie{}mcron}). @end deftp +@cindex scron +@cindex scheduling jobs +The @code{(gnu services scron)} module provides an interface to +scron, a simple daemon to run jobs at scheduled times. scron is +similar to the traditional Unix @command{cron} daemon; +the main difference is that it is much simpler. + +Jobs are executed as root @i{via} the shell with working direction +@code{/}. Use @code{su} or corresponding Guile functions +(@pxref{Processes,,, guile, GNU Guile Reference Manual}). + +The example below defines an operating system that runs the +@command{updatedb} command (@pxref{Invoking updatedb,,, find, Finding +Files}) daily: + +@lisp +(use-modules (guix) (gnu) (gnu services scron)) +(use-package-modules base) + +(define updatedb-job + ;; Run 'updatedb' at 3AM every day. + (let* ((exp #~(begin + (execl (string-append #$findutils "/bin/updatedb") + "updatedb" + "--prunepaths=/tmp /var/tmp /gnu/store"))) + (script (program-file "updatedb-job" exp))) + (scron-job + (schedule "0 3 * * *") + (command script)))) + +(operating-system + ;; @dots{} + (services (cons (service scron-service-type + (scron-configuration + (jobs (list updatedb-job)))) + %base-services))) +@end lisp + +@defvr {Scheme Variable} scron-service-type + +This is the type of the @code{scron} service, whose value is an +@code{scron-configuration} object. + +This service type can be the target of a service extension that provides +it additional job specifications (@pxref{Service Composition}). In +other words, it is possible to define services that provide additional +mcron jobs to run. +@end defvr + +@deftp {Data Type} scron-configuration +Data type representing the configuration of scron. + +@table @asis +@item @code{scron} (default: @var{scron}) +The scron package to use. + +@item @code{jobs} +This is a list of scron jobs. +@end table +@end deftp + +@deftp {Data Type} scron-job +Data type representing an scron job. + +@table @asis +@item @code{schedule} +The job schedule, in Vixie cron syntax. See the @code{scron(1)} +man page for more information. + +@item @code{command} +The shell command to run, as a value that lowers to a string. +@end table +@end deftp + + @node Log Rotation @subsection Log Rotation diff --git a/gnu/local.mk b/gnu/local.mk index 80ef0f04d0..4602e464f7 100644 --- a/gnu/local.mk +++ b/gnu/local.mk @@ -554,6 +554,7 @@ GNU_SYSTEM_MODULES = \ %D%/services/nix.scm \ %D%/services/nfs.scm \ %D%/services/pam-mount.scm \ + %D%/services/scron.scm \ %D%/services/security-token.scm \ %D%/services/shepherd.scm \ %D%/services/sound.scm \ diff --git a/gnu/services/scron.scm b/gnu/services/scron.scm new file mode 100644 index 0000000000..b9b2983e96 --- /dev/null +++ b/gnu/services/scron.scm @@ -0,0 +1,103 @@ +;;; GNU Guix --- Functional package management for GNU +;;; Copyright © 2019 Robert Vollmert +;;; +;;; This file is part of GNU Guix. +;;; +;;; GNU Guix is free software; you can redistribute it and/or modify it +;;; under the terms of the GNU General Public License as published by +;;; the Free Software Foundation; either version 3 of the License, or (at +;;; your option) any later version. +;;; +;;; GNU Guix is distributed in the hope that it will be useful, but +;;; WITHOUT ANY WARRANTY; without even the implied warranty of +;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +;;; GNU General Public License for more details. +;;; +;;; You should have received a copy of the GNU General Public License +;;; along with GNU Guix. If not, see . + +(define-module (gnu services scron) + #:use-module (gnu services) + #:use-module (gnu services shepherd) + #:autoload (gnu packages suckless) (scron) + #:use-module (guix gexp) + #:use-module (guix records) + #:use-module (guix store) + #:use-module (ice-9 match) + #:use-module (srfi srfi-1) + #:export (scron-configuration + scron-configuration? + scron-configuration-scron + scron-configuration-jobs + + scron-job + scron-job? + scron-job-schedule + scron-job-command + + scron-service-type + scron-service)) + +;;; Commentary: +;;; +;;; This module implements a service to run instances of scron, a +;;; periodic job execution daemon. Example of a service: +;; +;; (service scron-service-type +;; (scron-configuration +;; (jobs (list (scron-job (schedule "*/15 * * * *") +;; (command "echo hello!")))))) +;;; +;;; Code: + +(define-record-type* scron-configuration + make-scron-configuration + scron-configuration? + (scron scron-configuration-scron ;package + (default scron)) + (jobs scron-configuration-jobs ;list of + (default '()))) + +(define-record-type* scron-job + make-scron-job + scron-job? + (schedule scron-job-schedule) + (command scron-job-command)) + +(define (crontab jobs) + (apply mixed-text-file "crontab" + (concatenate + (map + (match-lambda + (($ schedule command) + (list schedule " " command "\n"))) + jobs)))) + +(define scron-shepherd-services + (match-lambda + (($ scron jobs) + (list + (shepherd-service + (provision '(scron)) + (requirement '(user-processes)) + (start #~(make-forkexec-constructor + (list (string-append #$scron "/bin/crond") + "-n" ; don't fork + "-f" #$(crontab jobs)) + #:log-file "/var/log/scron.log")) + (stop #~(make-kill-destructor))))))) + +(define scron-service-type + (service-type (name 'scron) + (description + "Run the scron job scheduling daemon.") + (extensions + (list (service-extension shepherd-root-service-type + scron-shepherd-services))) + (compose concatenate) + (extend (lambda (config jobs) + (scron-configuration + (inherit config) + (jobs (append (scron-configuration-jobs config) + jobs))))) + (default-value (scron-configuration)))) diff --git a/gnu/tests/base.scm b/gnu/tests/base.scm index a891711844..b80e77be66 100644 --- a/gnu/tests/base.scm +++ b/gnu/tests/base.scm @@ -28,6 +28,7 @@ #:use-module (gnu services dbus) #:use-module (gnu services avahi) #:use-module (gnu services mcron) + #:use-module (gnu services scron) #:use-module (gnu services shepherd) #:use-module (gnu services networking) #:use-module (gnu packages base) @@ -48,6 +49,7 @@ %test-halt %test-cleanup %test-mcron + %test-scron %test-nss-mdns)) (define %simple-os @@ -720,6 +722,90 @@ non-ASCII names from /tmp.") (description "Make sure the mcron service works as advertised.") (value (run-mcron-test name)))) + +;;; +;;; Scron. +;;; + +(define %scron-os + ;; System with an scron service, with one scron job for "root" and one scron + ;; job for an unprivileged user. + (let ((job1 + (scron-job + (schedule "* * * * *") + (command "(id -u; id -g) > witness"))) + (job2 + (scron-job + (schedule "* * * * *") + (command "su -c '(id -u; id -g) > ~/witness' alice"))) + (job3 + (scron-job + (schedule "* * * * *") + (command "touch witness-touch")))) + (simple-operating-system + (service scron-service-type + (scron-configuration (jobs (list job1 job2 job3))))))) + +(define (run-scron-test name) + (define os + (marionette-operating-system + %scron-os + #:imported-modules '((gnu services herd) + (guix combinators)))) + + (define test + (with-imported-modules '((gnu build marionette)) + #~(begin + (use-modules (gnu build marionette) + (srfi srfi-64) + (ice-9 match)) + + (define marionette + (make-marionette (list #$(virtual-machine os)))) + + (mkdir #$output) + (chdir #$output) + + (test-begin "scron") + + (test-assert "service running" + (marionette-eval + '(begin + (use-modules (gnu services herd)) + (start-service 'scron)) + marionette)) + + ;; Make sure root's scron job runs, has its cwd set to "/", and + ;; runs with the right UID/GID. + (test-equal "root's job" + '(0 0) + (wait-for-file "/witness" marionette)) + + ;; Likewise for Alice's job. We cannot know what its GID is since + ;; it's chosen by 'groupadd', but it's strictly positive. + (test-assert "alice's job" + (match (wait-for-file "/home/alice/witness" marionette) + ((1000 gid) + (>= gid 100)))) + + ;; Last, the job that uses a command; allows us to test whether + ;; $PATH is sane. + (test-equal "root's job with command" + "" + (wait-for-file "/witness-touch" marionette + #:read '(@ (ice-9 rdelim) read-string))) + + (test-end) + (exit (= (test-runner-fail-count (test-runner-current)) 0))))) + + (gexp->derivation name test)) + +(define %test-scron + (system-test + (name "scron") + (description "Make sure the scron service works as advertised.") + (value (run-scron-test name)))) + ;;; ;;; Avahi and NSS-mDNS. -- 2.24.0