PT Commons

h1. Setting up NRPE on Debian server

{{>toc}}

Process:

h2. on client server

h3. Install NRPE

<pre>

aptitude install nagios-nrpe-server nagios-plugins-basic

</pre>

h3. Edit config file

<pre>

vim /etc/nagios/nrpe.cfg

</pre>

* Add IP_v4_of_Nagios_server to allowed_hosts

h3. start service

<pre>

service nagios-nrpe-server restart

</pre>

h3. check that service is running

<pre>

netstat -tpln | grep 5666

</pre>

h3. edit local config to add specified checks

<pre>

vim /etc/nagios/nrpe_local.cfg

</pre>

Add NRPE test check, disk check, and Apache SIGTERM check

<pre>

0 octavia:/etc/nagios# cat nrpe_local.cfg 

######################################

# Do any local nrpe configuration here

######################################

command[check_nrpe_daemon]=/bin/echo "NRPE OK"

# disk checks

command[check_disk_root]=/usr/lib/nagios/plugins/check_disk -w 20% -c 10% -p /dev/root

# checking Apache logs for SIGTERM

command[check_apache_sigterm]=/usr/lib/nagios/plugins/check_cat.sh /var/log/apache2/error.log SIGTERM 0

</pre>

h3. add check_cat

In /usr/lib/nagios/plugins create check_cat.sh

<pre>

#!/bin/bash

#

# checks in files if there are instances of a given string.

# $1 is the file

# $2 is the string

# $3 is the threshold, any more than $3 and it will be Critical

cnt=`cat $1|grep $2|wc -l`

recent=`cat $1|grep $2`

if [ $cnt -le $3 ] ; then

        echo OK - no errors or warnings

        exit 0

fi

echo -e "CRITICAL - String $2 appeared $cnt times\n$recent"

exit 2

</pre>

Make it executable

<pre>

chmod 755 /usr/lib/nagios/plugins/check_cat.sh

</pre>

h3. Make total procs check ignore kernel processes

Add -k to the total_procs check in /etc/nagios/nrpe.cfg, and lower the threshold.

<pre>

command[check_total_procs]=/usr/lib/nagios/plugins/check_procs -k -w 130 -c 180

</pre>

h3. restart service

<pre>

service nagios-nrpe-server restart

</pre>

h2. on monitoring server

h3. test connection

On Nagios/Icinga server test that that worked:

<pre>

/usr/lib/nagios/plugins/check_nrpe -H clientserveruri.com -c check_nrpe_daemon

NRPE OK

</pre>

h3. set up checks.

example service config file

<pre>

###############################################################################

###############################################################################

#

# SERVICE DEFINITIONS

#

###############################################################################

###############################################################################

define service{

        use                     generic-service         ; Inherit default values from a template

        host_name               clientserver

        service_description     SSH

        check_command           check_ssh

        }

define service{

        use                     generic-service         ; Inherit default values from a template

        host_name               clientserver

        service_description     HTTP

        check_command           check_http

        }

define service{

        use                     generic-service         ; Inherit default values from a template

        host_name               clientserver

        service_description     Users

        check_command           check_nrpe_1arg!check_users

        }

define service{

        use                     generic-service         ; Inherit default values from a template

        host_name               clientserver

        service_description     Load

        check_command           check_nrpe_1arg!check_load

        }

define service{

        use                     generic-service         ; Inherit default values from a template

        host_name               clientserver

        service_description     Zombie Processes

        check_command           check_nrpe_1arg!check_zombie_procs

        }

define service{

        use                     generic-service         ; Inherit default values from a template

        host_name               clientserver

        service_description     Total Processes

        check_command           check_nrpe_1arg!check_total_procs

        }

define service{

        use                     generic-service         ; Inherit default values from a template

        host_name               clientserver

        service_description     Disk Space /root

        check_command           check_nrpe_1arg!check_disk_root

        }

define service{

        use                     generic-service         ; Inherit default values from a template

        host_name               clientserver

        service_description     Apache SIGTERM

        check_command           check_nrpe_1arg!check_apache_sigterm

        }

</pre>

h3. restart monitoring service

for icinga

<pre>

/etc/init.d/icinga restart

</pre>

sources:

http://xmodulo.com/2014/03/nagios-remote-plugin-executor-nrpe-linux.html

https://wiki.icinga.org/display/howtos/Setting+up+NRPE+with+Icinga