Table of Contents
Restart a Process
Table of Contents
This is a standalone policy that will restart three CFEngine processes if they are not running.
body common control
{
bundlesequence => { "process_restart" };
}
bundle agent process_restart
{
vars:
"component" slist => { # List of processes to monitor
"cf-monitord",
"cf-serverd",
"cf-execd"
};
processes:
"$(component)"
restart_class => canonify("start_$(component)"); # Set the class "start_<component>" if it is not running
commands:
"/var/cfengine/bin/$(component)"
ifvarclass => canonify("start_$(component)"); # Evaluate the class "start_<component>", CFEngine will run
# the command if "start_<component> is set.
}
Notes: The canonify
function translates illegal characters to underscores, e.g. start_cf-monitord
becomes start_cf_monitord
. Only alphanumerics and underscores are allowed in CFEngine identifiers (names of variables, classes, bundles, etc.)
This policy can be found in /var/cfengine/share/doc/examples/unit_process_restart.cf
.
Example run:
# ps -ef |grep cf-
root 4305 1 0 15:14 ? 00:00:02 /var/cfengine/bin/cf-execd
root 4311 1 0 15:14 ? 00:00:05 /var/cfengine/bin/cf-serverd
root 4397 1 0 15:15 ? 00:00:06 /var/cfengine/bin/cf-monitord
# kill 4311
# ps -ef |grep cf-
root 4305 1 0 15:14 ? 00:00:02 /var/cfengine/bin/cf-execd
root 4397 1 0 15:15 ? 00:00:06 /var/cfengine/bin/cf-monitord
# cf-agent -f unit_process_restart.cf
# ps -ef |grep cf-
root 4305 1 0 15:14 ? 00:00:02 /var/cfengine/bin/cf-execd
root 4397 1 0 15:15 ? 00:00:06 /var/cfengine/bin/cf-monitord
root 8008 1 0 18:18 ? 00:00:00 /var/cfengine/bin/cf-serverd
#
And again, in Inform mode:
# kill 8008
# cf-agent -f unit_process_restart.cf -I
2013-06-08T18:19:51-0700 info: This agent is bootstrapped to '192.168.183.208'
2013-06-08T18:19:51-0700 info: Running full policy integrity checks
2013-06-08T18:19:51-0700 info: /process_restart/processes/'$(component)': Making a one-time restart promise for 'cf-serverd'
2013-06-08T18:19:51-0700 info: Executing 'no timeout' ... '/var/cfengine/bin/cf-serverd'
2013-06-08T18:19:52-0700 info: Completed execution of '/var/cfengine/bin/cf-serverd'
#