Creating Custom Template in pnp4nagios

Some time need to create custom template in pnp4nagios for some command which behave differently when execute on remote host as the appearance of graphs depends on the check command used. eg check_nrpe

Example:

define command {
command_name check_nrpe
command_line $USER1$/check_nrpe -H $HOSTADDRESS$ -c $ARG1$
}

This would lead to a call of the check_nrpe.php template even when the monitored host would use a completely different plugin which is called via NRPE, eg

In service definition

define service{
use local-service,srv-pnp
host_name SomeHost
service_description Current Load
check_command check_nrpe!check_load
}

This will lead to call to check_nrpe command and it will use the default.php PNP template which may or may not give the graph as required.

Solution: Custom Template

1. Define new command in nagios/commands.cfg

define command{
command_name check_nrpe_load
command_line $USER1$/check_nrpe -H $HOSTADDRESS$ -c $ARG1$
}

2. Modify the service command for the host to use the new command

define service{
use local-service,srv-pnp
host_name SomeHost
service_description Current Load
check_command check_nrpe_load!check_load
}

Reload Nagios so that it start using the new check command.

At this point everything will be working just as before,

Pnp4nagios configuration

1. Define a check command /usr/local/pnp4nagios/etc/check_commands/check_nrpe_load.cfg (with the same name as the check command in above example)

Tip: Just copy the sample command definition /usr/local/pnp4nagios/etc/check_commands/check_nwstat.cfg-sample eg

cd /usr/local/pnp4nagios/etc/check_commands
sudo cp check_nwstat.cfg-sample check_nrpe_load.cfg

For more detail on custom command refer to http://docs.pnp4nagios.org/pnp-0.6/tpl_custom

2. Define a customer template for check_nrpe_load

In the above example if check_nrpe_load.cfg have

CUSTOM_TEMPLATE = 0,1 the it will results in → "check_nrpe_load_check_load.php"

Create a custom template in /usr/local/pnp4nagios/share/templates (pnp4nagios first look for template in this direcotry then fallback to other directories http://docs.pnp4nagios.org/pnp-0.6/tpl)

Note: Or you can just create a symbolic link to existing template that come with pnp4nagios installation eg ...

ln -s ../templates.dist/check_load.php check_nrpe_load_check_load.php

Here is the sample template for check_load on remote hosts that will plot graph of 1M and 15 minute graph for a host,

cd /usr/local/pnp4nagios/share/templates

sudo vi check_nrpe_load_check_load.php (template name should match with the custom command definition in our example check_nrpe_load_check_load.php)

<?php
$opt[1] = "--vertical-label Load -l0  -u 1 --title \"CPU Load for $hostname / $servicedesc\" ";

$def[1] =  "DEF:var1=$rrdfile:$DS[1]:AVERAGE " ;
$def[1] .= "DEF:var2=$rrdfile:$DS[2]:AVERAGE " ;
$def[1] .= "DEF:var3=$rrdfile:$DS[3]:AVERAGE " ;
if ($WARN[1] != "") {
    $def[1] .= "HRULE:$WARN[1]#FFFF00 ";
}
if ($CRIT[1] != "") {
    $def[1] .= "HRULE:$CRIT[1]#FF0000 ";
}
$def[1] .= "AREA:var1#EACC00:\"Load average  1 min \" " ;
$def[1] .= "GPRINT:var1:LAST:\"%6.2lf last\" " ;
$def[1] .= "GPRINT:var1:AVERAGE:\"%6.2lf avg\" " ;
$def[1] .= "GPRINT:var1:MAX:\"%6.2lf max\\n\" ";
$def[1] .= "LINE:var3#FF0000:\"Load average 15 min \" " ;
$def[1] .= "GPRINT:var3:LAST:\"%6.2lf last\" " ;
$def[1] .= "GPRINT:var3:AVERAGE:\"%6.2lf avg\" " ;
$def[1] .= "GPRINT:var3:MAX:\"%6.2lf max\\n\" " ;
?>