I came across check_mk when looking for plugins for our Nagios installation, at that time I did not have the time to check it out. A project I'm working on at a customer site needs monitoring and I decided to try check_mk.
check_mk is an add on to Nagios build by a German Linux consulting firm. We already had a running installation of Nagios and pnp4nagios on a CentOs server. Nagios is a prerequisite for installing check_mq, I'm not sure if pnp4nagios is required or not.
There are several installation images available in rpm and deb format but I decided to go for that from source installation.
If you have the compiler available this is pretty straightforward. Download the tarball , extract it and start setup.sh. setup.sh has a character based nice interface and it auto-detects most if not all answers to the questions
Just follow the instructions . I had two minor issues.
gcc-c++ was not installed this caused the first install to fail, also mod_python was missing. This is mentioned in the requirements in the documenation but it would be nice if the setup script would check this.
The second is was that the auto-detected AuthUserFile for the httpd configuration was not the correct one. This was probably caused by an older Nagios install on the same server.
After the setup you just navigate your browser to your-nagios-server/check_mk where you get a brand new look for your exisiting Nagios information.