nixpkgs/nixos/modules/services/scheduling/cron.nix
Rob Vermaas b48e41b8d7 cron: make into systemd.service and make it depend on /etc/localtime
so that changes in timezone will trigger a restart of cron service.
2014-12-15 14:50:12 +01:00

127 lines
3.5 KiB
Nix

{ config, lib, pkgs, ... }:
with lib;
let
inherit (config.services) jobsTags;
# Put all the system cronjobs together.
systemCronJobsFile = pkgs.writeText "system-crontab"
''
SHELL=${pkgs.bash}/bin/bash
PATH=${config.system.path}/bin:${config.system.path}/sbin
${optionalString (config.services.cron.mailto != null) ''
MAILTO="${config.services.cron.mailto}"
''}
NIX_CONF_DIR=/etc/nix
${lib.concatStrings (map (job: job + "\n") config.services.cron.systemCronJobs)}
'';
# Vixie cron requires build-time configuration for the sendmail path.
cronNixosPkg = pkgs.cron.override {
# The mail.nix nixos module, if there is any local mail system enabled,
# should have sendmail in this path.
sendmailPath = "/var/setuid-wrappers/sendmail";
};
allFiles = map (f: "\"${f}\"") (
[ "${systemCronJobsFile}" ] ++ config.services.cron.cronFiles
);
in
{
###### interface
options = {
services.cron = {
enable = mkOption {
type = types.bool;
default = true;
description = "Whether to enable the Vixie cron daemon.";
};
mailto = mkOption {
type = types.nullOr types.str;
default = null;
description = "Email address to which job output will be mailed.";
};
systemCronJobs = mkOption {
type = types.listOf types.str;
default = [];
example = literalExample ''
[ "* * * * * test ls -l / > /tmp/cronout 2>&1"
"* * * * * eelco echo Hello World > /home/eelco/cronout"
]
'';
description = ''
A list of Cron jobs to be appended to the system-wide
crontab. See the manual page for crontab for the expected
format. If you want to get the results mailed you must setuid
sendmail. See <option>security.setuidOwners</option>
If neither /var/cron/cron.deny nor /var/cron/cron.allow exist only root
will is allowed to have its own crontab file. The /var/cron/cron.deny file
is created automatically for you. So every user can use a crontab.
Many nixos modules set systemCronJobs, so if you decide to disable vixie cron
and enable another cron daemon, you may want it to get its system crontab
based on systemCronJobs.
'';
};
cronFiles = mkOption {
type = types.listOf types.path;
default = [];
description = ''
A list of extra crontab files that will be read and appended to the main
crontab file when the cron service starts.
'';
};
};
};
###### implementation
config = mkIf (config.services.cron.enable && allFiles != []) {
security.setuidPrograms = [ "crontab" ];
environment.systemPackages = [ cronNixosPkg ];
systemd.services.cron =
{ description = "Cron Daemon";
wantedBy = [ "multi-user.target" ];
preStart =
''
rm -f /etc/crontab
cat ${toString allFiles} > /etc/crontab
chmod 0600 /etc/crontab
mkdir -m 710 -p /var/cron
# By default, allow all users to create a crontab. This
# is denoted by the existence of an empty cron.deny file.
if ! test -e /var/cron/cron.allow -o -e /var/cron/cron.deny; then
touch /var/cron/cron.deny
fi
'';
restartTriggers = [ config.environment.etc.localtime.source ];
serviceConfig.ExecStart = "${cronNixosPkg}/bin/cron -n";
};
};
}