Installing Nagios 3.5 on Ubuntu 12.04 with Plugins 1.4.11

Nagios is a powerful monitoring system that enables organizations to identify and resolve IT infrastructure problems before they affect critical business processes.

First launched in 1999, Nagios has grown to include thousands of projects developed by the worldwide Nagios community. Nagios is officially sponsored by Nagios Enterprises, which supports the community in a number of different ways through sales of its commercial products and services.

Nagios monitors your entire IT infrastructure to ensure systems, applications, services, and business processes are functioning properly. In the event of a failure, Nagios can alert technical staff of the problem, allowing them to begin remediation processes before outages affect business processes, end-users, or customers. With Nagios you'll never be left having to explain why a unseen infrastructure outage hurt your organization's bottom line.

This is how we installed Nagios Core 3.5 in Ubuntu 12.04 with Plugins V. 1.4.11


Step 1 : Install the necessary packages and libraries


You have to install the following packages on your Ubuntu installation before continuing.

    Apache 2
    PHP
    GCC compiler and development libraries
    GD development libraries

You can use apt-get to install these packages by running the following commands:

sudo apt-get install apache2

sudo apt-get install libapache2-mod-php5

sudo apt-get install build-essential

sudo apt-get install libgd2-xpm-dev


Step 2 : Create Account Information

Become the root user.

sudo -s

Create a new nagios user account and give it a password.

/usr/sbin/useradd -m -s /bin/bash nagios

passwd nagios

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On older Ubuntu server editions (6.01 and earlier), you will need to also add a nagios group (it's not created by default). You need not to do this step on new editions of Ubuntu.

/usr/sbin/groupadd nagios

/usr/sbin/usermod -G nagios nagios 

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Create a new nagcmd group for allowing external commands to be submitted through the web interface. Add both the nagios user and the apache user to the group.

/usr/sbin/groupadd nagcmd

/usr/sbin/usermod -a -G nagcmd nagios

/usr/sbin/usermod -a -G nagcmd www-data

Step 3 : Download Nagios and the Plugins

Create a directory for storing the downloads.

mkdir ~/downloads

cd ~/downloads

Download the source code tarballs of both Nagios and the Nagios plugins (visit http://www.nagios.org/download/ for links to the latest versions). These directions were tested with Nagios 3.5.0 and Nagios Plugins 1.4.11.

wget http://prdownloads.sourceforge.net/sourceforge/nagios/nagios-3.2.3.tar.gz

wget http://prdownloads.sourceforge.net/sourceforge/nagiosplug/nagios-plugins-1.4.11.tar.gz

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If you don't have wget installed you can install it by using the command below

sudo apt-get install wget
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Step 4 : Compile and Install Nagios

Extract the Nagios source code tarball.

cd ~/downloads

tar xzf nagios-3.5.0.tar.gz

cd nagios

Run the Nagios configure script, passing the name of the group you created earlier like so:

./configure --with-command-group=nagcmd

Compile the Nagios source code.
 
make all

Install binaries, init script, sample config files and set permissions on the external command directory.

make install

make install-init

make install-config

make install-commandmode

Don't start Nagios yet - there's still more that needs to be done...

Step 5 : Configure the Web Interface

Install the Nagios web config file in the Apache conf.d directory.

make install-webconf

Create a nagiosadmin account for logging into the Nagios web interface. Remember the password you assign to this account - you'll need it later.

htpasswd -c /usr/local/nagios/etc/htpasswd.users nagiosadmin

Restart Apache to make the new settings take effect.

/etc/init.d/apache2 reload

Step 6 : Compile and Install the Nagios Plugins

Extract the Nagios plugins source code tarball.

cd ~/downloads

tar xzf nagios-plugins-1.4.11.tar.gz

cd nagios-plugins-1.4.11

Compile and install the plugins.

./configure --with-nagios-user=nagios --with-nagios-group=nagios

make

make install

Step 7 : Start Nagios

Configure Nagios to automatically start when the system boots.

ln -s /etc/init.d/nagios /etc/rcS.d/S99nagios

Verify the sample Nagios configuration files.

 /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg

If there are no errors, start Nagios.

/etc/init.d/nagios start

Step 8 : Login to the Web Interface

You should now be able to access the Nagios web interface at the URL below. You'll be prompted for the username (nagiosadmin) and password you specified earlier.

http://localhost/nagios/

Click on the "Service Detail" navbar link to see details of what's being monitored on your local machine. It will take a few minutes for Nagios to check all the services associated with your machine, as the checks are spread out over time.