Configure Nagios on Ubuntu: Part 1 – Nagios Server

This article is part of a 2-part series about installing and configuring Nagios on Ubuntu 14.04.

• Part 1: Nagios Server
• Part 2: Remote Host

Overview

Nagios is a popular server monitoring software suite which can help greatly improve the uptime of your application. In this guide, I’m going to show you how to install Nagios on Ubuntu 14.04.

You need a LAMP stack installed on your server to be able to use Nagios. If you would like to learn how you can do this on Ubuntu, please refer to the guide: How to Install Apache, MySQL, and PHP on Ubuntu

Step 1: Installing prerequisites

Aside from a functioning LAMP stack, there are three prerequisites. Install them with apt-get:

apt-get install build-essential libgd2-xpm-dev apache2-utils

Step 2: Creating a group and user

For Nagios, we need to create a group and user. First off, create the user:

useradd -m nagios

If you didn’t give it a password yet, do this with the passwd command:

passwd nagios

We will now create the Nagios group:

groupadd nagcmd

Add the Nagios user to the Nagios group:

usermod -a -G nagcmd nagios

And add the www-data user to the Nagios group:

usermod -a -G nagcmd www-data

Step 3: Downloading Nagios

Now, we can download Nagios. Install wget now, if you don’t already have it installed:

apt-get install wget

Then, download the Nagios files:

wget http://prdownloads.sourceforge.net/sourceforge/nagios/nagios-4.0.8.tar.gz
wget http://nagios-plugins.org/download/nagios-plugins-2.0.3.tar.gz

Untar it:

tar xzf nagios*

And finally, navigate to the directory:

cd nagios*

Step 4: Installing Nagios

Now that our server is setup, we can compile and install Nagios.

./configure --with-command-group=nagcmd
make all
make install
make install-init
make install-config
make install-commandmode
make install-webconf

Step 5: Configuring the Nagios web interface

Nagios features a web interface for easy management. For security purposes, you should limit who can access the web interface with either a firewall or a password-protected Apache configuration.

Restart Apache:

service apache2 restart

Start the Nagios service:

service nagios start

Continue to: Part 2: Remote Host