In network and services monitoring, Nagios Core stands as a prominent tool. However, to further enhance its capabilities, we introduce Nagios Remote Plugin Executor (NRPE). NRPE is an agent that allows Nagios plugins to be executed remotely on other Linux/Unix machines. It can also communicate with Windows agent addons like NSClient++, enabling monitoring of resources such as disk usage, CPU load, and more.
This guide will walk you through the process of installing and configuring Nagios NRPE on your Nagios server.
Installation Steps
Step 1: Install Nagios NRPE and Nagios-devel
Nagios-devel comprises header files, libraries, and development documentation for Nagios. To install Nagios NRPE and Nagios-devel, use the following command:
[root@server ~]# yum --enablerepo=rpmforge install nagios-nrpe nagios-devel
This command will resolve dependencies and install the necessary packages.
Example:
[root@server ~]# yum --enablerepo=rpmforge install nagios-nrpe nagios-devel Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * addons: ossm.utm.my * base: ossm.utm.my * epel: ftp.cuhk.edu.hk * extras: ossm.utm.my * rpmforge: fr2.rpmfind.net * updates: ossm.utm.my Setting up Install Process Resolving Dependencies --> Running transaction check ---> Package nagios-devel.i386 0:3.2.3-3.el5.rf set to be updated ---> Package nagios-nrpe.i386 0:2.12-1.el5.rf set to be updated --> Finished Dependency Resolution Dependencies Resolved ===================================================================================== Package Arch Version Repository Size ===================================================================================== Installing: nagios-devel i386 3.2.3-3.el5.rf rpmforge 42 k nagios-nrpe i386 2.12-1.el5.rf rpmforge 35 k Transaction Summary ===================================================================================== Install 2 Package(s) Upgrade 0 Package(s) Total download size: 76 k Is this ok [y/N]: y Downloading Packages: (1/2): nagios-nrpe-2.12-1.el5.rf.i386.rpm | 35 kB 00:00 (2/2): nagios-devel-3.2.3-3.el5.rf.i386.rpm | 42 kB 00:00 ------------------------------------------------------------------------------------- Total 23 kB/s | 76 kB 00:03 Running rpm_check_debug Running Transaction Test Finished Transaction Test Transaction Test Succeeded Running Transaction Installing : nagios-nrpe 1/2 Installing : nagios-devel 2/2 Installed: nagios-devel.i386 0:3.2.3-3.el5.rf nagios-nrpe.i386 0:2.12-1.el5.rf Complete!
Step 2: Set NRPE to Start at Boot and Start NRPE
To ensure NRPE starts automatically at boot, use the following command:
[root@server ~]# chkconfig nrpe on
To start NRPE, use the following command:
[root@server ~]# /etc/init.d/nrpe start ... Starting Nagios NRPE daemon (nrpe): [ OK ]
Step 3: Update /etc/services
Add the following line at the bottom of the /etc/services file:
[root@server ~]# vi /etc/services nrpe 5666/tcp # NRPE
Step 4: Test NRPE Daemon Install
To verify that the NRPE daemon has been installed correctly, use the following command:
[root@server ~]# netstat -at |grep nrpe
If the installation was successful, you should see output similar to the following:
tcp 0 0 server.intranet.local:nrpe *:* LISTEN
Commands Mentioned
- yum –enablerepo=rpmforge install nagios-nrpe nagios-devel – Installs Nagios NRPE and Nagios-devel
- chkconfig nrpe on – Sets NRPE to start at boot
- /etc/init.d/nrpe start – Starts NRPE
- vi /etc/services – Opens the /etc/services file for editing
- netstat -at |grep nrpe – Checks if NRPE daemon is installed and running
Conclusion
Nagios NRPE is a powerful tool that enhances the capabilities of Nagios Core by allowing remote execution of Nagios plugins on other Linux/Unix machines.
This tutorial has provided you with step-by-step instructions on how to install and configure Nagios NRPE on your Nagios server. By following these steps, you can effectively monitor resources such as disk usage, CPU load, and more on your network. For more in-depth information on various web servers, you can explore our articles on best web servers, Apache, Nginx, and LiteSpeed. If you’re interested in different hosting options, we also have articles on dedicated server, VPS server, cloud hosting, and shared hosting.
Remember, the key to effective network and services monitoring lies in the proper installation and configuration of your tools.
FAQ
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What is Nagios NRPE?
Nagios NRPE, or Nagios Remote Plugin Executor, is an agent that allows Nagios plugins to be executed remotely on other Linux/Unix machines. It can also communicate with Windows agent addons like NSClient++, enabling monitoring of resources such as disk usage, CPU load, and more.
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What is Nagios-devel?
Nagios-devel comprises header files, libraries, and development documentation for Nagios. It is necessary for the installation and functioning of Nagios NRPE.
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How do I start NRPE?
You can start NRPE by using the command “/etc/init.d/nrpe start”. This command initiates the Nagios NRPE daemon.
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How do I set NRPE to start at boot?
You can set NRPE to start at boot by using the command “chkconfig nrpe on”. This ensures that NRPE automatically starts whenever your server boots up.
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How do I verify that NRPE is installed and running?
You can verify that NRPE is installed and running by using the command “netstat -at |grep nrpe”. If NRPE is running, this command will return output indicating that the NRPE daemon is listening.