On Wed, Nov 10, 2010 at 3:53 PM, Sandra Wittenbrock
<san...@hpcrd.lbl.gov> wrote:
> Hi,
>
> What would be the command to make sure a service (sysctl, firewall, etc)
> is running, and/or restart it when cfengine updates the config files?
Here is what I use on a Linux server - if somebody has a better way, I would
love to hear it:
a) how to make sure a service is running:
check that CUPS (printer service) is running by checking the "ps" output, and
if regex match for "cups" fails, restarting cups:
--- start cfengine config ----
body common control
{
bundlesequence => { "check_cups_running" };
}
########################################
bundle agent check_cups_running {
processes:
"cupsd"
restart_class => "start_cups";
# restart_class sets up a class if the regex match FAILS
commands:
start_cups::
"/etc/init.d/cups start";
}
--- end cfengine config file ---
It just occurred to me that a more reliable test would be to pretend
to be a client for that service and to try to connect to it, and if it
fails then to try to restart. (more reliable because if there is
another process in the process table, let's say a program called
mycupsarefull, but cups is not running, cfengine will not proceed to
restart CUPS)
but anyway, the above does work and should help you start, Sandra
now, question b: how to restart a service if it's config file was
recently updated
correct me if I'm mistaken, but there is presently no way in cfengine
to natively test if a file modification time is less than 10 minutes,
let's say. there is function isnewerthan() but it can only compare
two files, not a file and a time period.
Hence, I use:
(the following is an example for restarting haproxy if
/etc/haproxy.conf was recently updated. )
--- start cfengine config ----
body common control
{
bundlesequence => {
"restart_load_balancer_if_load_balancer_config_recently_updated" };
inputs => { "cfengine_stdlib.cf" };
}
bundle agent restart_load_balancer_if_load_balancer_config_recently_updated
{
commands:
load_balancer_hosts::
"/usr/bin/find /etc/haproxy.conf -mmin -10 | /bin/grep haproxy.conf
>/dev/null && /usr/bin/pkill
haproxy && /usr/local/sbin/haproxy -f /etc/haproxy.conf || exit 0"
contain => in_shell;
}
--- end cfengine config ----
note: i tried using "pkill -HUP haproxy" orriginally but this didn't
seem to work... I have to
research what haproxy does when it gets SIGHUP. in this example, I
stop and start
the proxy. normally, I'd expect pkill -HUP to be sufficient to reload
the config.
Hope this helps!
Best,
-at
_______________________________________________
Help-cfengine mailing list
Help-cfengine@cfengine.org
https://cfengine.org/mailman/listinfo/help-cfengine
