NRPE (Nagios Remote Plugin Executor) is used for executing Nagios plugins on remote client systems. In previous article we had described about installation of Nagios Server on Ubuntu operating system. This article will help you to install NRPE on Ubuntu 18.04 LTS, 16.04 LTS & LinuxMint 19/18 systems.
Step 1 – Install NRPE on Ubuntu
NRPE is available under default apt repositories of Ubuntu systems. Execute the following command to install it
sudo apt-get update sudo apt-get install nagios-nrpe-server nagios-plugins
Step 2 – Configure NRPE
In NRPE configuration, first we need to nrpe to which nagios servers it accepts requests, For example your nagios server ip is 192.168.1.100, then add this ip to allowed hosts list. Edit NRPE configuration file /etc/nagios/nrpe.cfg and make changes like
we can add more Nagios servers in allowed hosts by a comma-separated list.
Now restart NRPE service. Now it is ready to listen to requests from Nagios server
sudo /etc/init.d/nagios-nrpe-server restart
Step 3 – Verify Connection
Let’s verify the connection between the Nagios server and NRPE client machine. Login to your Nagios server and check the Nagios server can communicate with NRPE service properly.
Use check_nrpe command on the Nagios server under the plugins directory. The command will be like as below here 192.168.1.11 is the IP address of client machine.
check_nrpe -H 192.168.1.11 NRPE v2.15
The output “NRPE v2.15” shows that the Nagios server successfully communicated with NRPE.
Step 4 – Add Check Commands in NRPE
All the services check commands with the nagios plugins packages, which is by default installed in /usr/lib/nagios/plugins/ for 32 bit systems. Default installation adds few commands in configuration file. Add more commands as per your requirements like below
command[check_users]=/usr/lib/nagios/plugins/check_users -w 5 -c 10 command[check_load]=/usr/lib/nagios/plugins/check_load -w 15,10,5 -c 30,25,20 command[check_hda1]=/usr/lib/nagios/plugins/check_disk -w 20% -c 10% -p /dev/hda1 command[check_zombie_procs]=/usr/lib/nagios/plugins/check_procs -w 5 -c 10 -s Z command[check_total_procs]=/usr/lib/nagios/plugins/check_procs -w 150 -c 200
Step 5 – Start/Stop NRPE Service
Use the following commands to start, stop or restart NRPE service. Each time we make any changes in the configuration file required to restart service
sudo /etc/init.d/nagios-nrpe-server stop sudo /etc/init.d/nagios-nrpe-server start sudo /etc/init.d/nagios-nrpe-server restart