To get Nagios up and running, you initially need to download two packages. One is the Nagios core package, which includes the Nagios daemon and its web interface. The second is the Official Nagios Plug-ins. At the time of this writing, the core Nagios package is at version 2.5, and the Official Nagios Plug-ins package is at version 1.4.3. You can find links to both packages at Nagios’s download page at http://www.nagios.org/download/. As an alternative to downloading and compiling manually, you can also install a package for your operating system, depending on your distribution, how many distributions you have, which distributions carry Nagios, and which do not carry the 2.x branch and are still using 1.x. This document assumes you are using Nagios 2.x. The rest of our installation steps will deal with downloading and compiling manually. We will start with the Nagios core package.
It is a wise idea to have Nagios operate as its own user. Furthermore, in order to use the web interface, Apache will also need to run with permissions to access some of Nagios’s files. Therefore, the first step is to create our required users and set up our groups:
localhost:~ # groupadd nagios localhost:~ # useradd –g nagios –d /usr/local/nagios –c "Nagios User" nagios localhost:~ # usermod –G nagios www-data
In the preceding steps, the first thing we did was to add a new group to our system. The reason we want a new group is so we can also add our web server’s user to the group so it ...