Graphvis visualisation of Nagios Config

Project Notes

I have written a couple of utilities one to walk a nagios config tree and turn it into a perl hash (called nagparse)and another to use that hash converting the tree into a graphvis directed graph (called graphit). These are then brought together with a CGI program called explorenagios that lets you select what parts of the config to graph. If you have a non trivial config then showing it ALL in one graph is not fun!

You can use the two component programs on the command line too - and feed the output into dot (it has been optomised to make nice dot graphs) or one of the other engines like neato if you want to do some hacking of the output options.

It is now useful enough to be worth sharing. Not prefect yet but useful. Surprisingly fast.

If you use the explorenagios with the debug flag checked the resulting output can be used with the Twiki wiki GraphVis plugin too.

If you are working on a large and complex configuration being able to see large groups of hosts and how they link up to services etc on a graph is a great fault finding aid. You get to spot the odd ones out easily.