In this tutorial we look at installing the renowned monitoring software Nagios 3 core onto Ubuntu 12.04 LTS server. This is installing onto a clean install of Ubuntu where we choose to install the basic server with SSH and LAMP. Nagios is reliant on the LAMP stack.
With the install complete and the network configuration finished we are ready to install nagios 3
sudo apt-get install -y nagios3
During the install the dpkg-reconfigure program will run and will prompt for the email server to be configured. In the example we leave it at an Internet Host, we can pass SMTP messages to another server on the internet so long as it will relay from us. We also set the password for nagiosadmin the nagios web user.
I would restart the apache at this stage
sudo service apache restart
Now we are ready to access the Nagios site. From a browser we visit:
http://192.168.0.7/nagios3
And authenticate as nagiosadmin with the password we set.