ZhoubaWiki:IcingaEventHandlerInstallation - Revision history

Garak: Created page with " Category:Zhouba {| align="right" | TOC |} '''Introduction to Setting up event handlers triggering on remote servers'''
2021-05-22T16:40:12Z

Created page with " Category:Zhouba  {| align="right" | TOC |} '''Introduction to Setting up event handlers triggering on remote servers'''<br..."

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[[Category:Zhouba]]

{| align="right"
| TOC
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'''Introduction to Setting up event handlers triggering on remote servers'''<br><br>
For illustration <code>eh_restart_service</code> event handler installation is described

==Monitoring server part==
Having <code>check_remote</code> set up this way:
<pre>
define command {
command_name check_remote
command_line $USER1$/check_nrpe -H $HOSTADDRESS$ -p $_HOSTPORT$ -u -c $ARG1$ -t 120
}
</pre>
simple new service definition row is to be added like this:
<tt># generic response code template
define service{
name response-code-template
use generic-service-charted
check_interval 0.25
retry_interval 0.25
max_check_attempts 3
flap_detection_enabled 0
register 0
}
# trackers
define service{
use response-code-template
hostgroup_name trackers
service_description Check HTTPS success response code
check_command check_https_success_response!S!/
<span style="color: red">'''event_handler check_remote!restart_service_tracker'''</span>
}
</tt>
Note that <code>max_check_attempts</code> directive has to be set to have a value of more than <code>1</code>, ideally at least <code>3</code>. It is so because event handlers are executed on soft states only (1/3, 2/3) - to avoid unnecessary notifications.

==Remote server part==
1. Copy the event handler script (can be in any executable form) the the remote server's plugin directory (typically <code>/usr/lib/nagios/plugins</code>)

2. Assign it as an NRPE plugin under tha same name as check_nrpe's parameter (in this case <code>restart_service_tracker</code>) into <code>nrpe.cfg</code> like this:
<pre>
command[restart_service_tracker]=sudo /usr/lib/nagios/plugins/eh_restart_service -s tracker
</pre>
:Note the usage of sudo prefix - it is so due to the necessity of broader privileges for services restarting.

3. Don't forget to restart the daemon afterwards
<pre>
/etc/init.d/nagios-nrpe-server restart
</pre>

4. Add the nagios user privilege to execute nagios plugins using sudo. /etc/sudoers snippet example follows:
<pre>
# Allow members of group sudo to execute any command
%sudo ALL=(ALL:ALL) NOPASSWD: ALL
nagios ALL=(ALL) NOPASSWD: /usr/lib/nagios/plugins/
</pre>

5. Now you can issue test command to verify everything on remote server is set up OK
<pre>
/usr/lib/nagios/plugins/check_nrpe -H localhost -c restart_service_tracker
</pre>
:This exact event handler outputs 'OK', exits with a code of 0 and writes log entry into <code>/icinga/eh_restart_service.log</code>. Consult source code of your event handler script to evaluate it works OK;-)

6. If still unsure it works ok, manually stop the service and issue the command of point 5 again. Then see service status and calm down.