As a System Administrator i have the need to monitor all my infrastructure. After searching the web i found that Nagios system is one of the most powerful and free monitoring software out there.
Nagios is a system monitoring for IT infrastructure that help to solve/detect problems before they affect the business process.
Lets start the installation.
Nagios is a system that runs on CentOS or Ubuntu. For this tutorial i am going to use Ubuntu Server 12.04.2 32bits
The Ubuntu Server installation is a very straight forward process so i am not going to focus on that.
After you install the Server lets update the repository list with the command:
$ sudo apt-get update
$ sudo apt-get upgrade
$ sudo apt-get install build-essential
Now to install the nagios just use the commands
$ apt-get install -y nagios3 nagios-nrpe-plugin
$ usermod -a -G nagios www-data
$ chmod -R g+x /var/lib/nagios3/
$ sed -i ‘s/check_external_commands=0/check_external_commands=1/g’ /etc/nagios3/nagios.cfg
now lets set the password for nagiosadmin
$ htpasswd -c /etc/nagios3/htpasswd.users nagiosadmin
restart the nagios3 and apache2 services
$ service nagios3 restart && service apache2 restart
Now your server is ready to be accessed from a internet browser. Just use the link http://ip_address_of_the_server/nagios3 in my case http://10.60.2.133/nagios3
That’s all for now.