Creating a custom Munin plugin
Odin's Reporter

© Carinabella, photocase.com
Munin collects information and plots parameters of your choice automatically and with minimal configuration. But if you can't find a plugin that captures the data you want to graph, you might have to roll your own.
Graphs make numerical data more accessible; or, as Edward R. Tufte puts it: "Graphics reveal data." [1] The Munin monitoring application is known for drawing simple and practical graphs. This helpful tool, which is named for a mythical raven who delivers news to the Norse god Odin, collects, stores, and plots data in daily, weekly, monthly, and annual charts (Figure 1).
Munin, a GPLed monitoring tool originally developed by the Norwegian Linux service provider Linpro [2], receives data through a system of plugins tailored for various monitoring activities. A collection of useful plugins come pre-bundled with the Munin monitoring tool, and other plugins are available from third-party sources on the Internet. However, if you are faced with a monitoring task that other users haven't imagined yet, you might need to create your own plug-in. The very extensible Munin lets you create custom plugins for monitoring a wide range of activities. In this article, I'll explain how to build a plugin that monitors airport departures and arrivals.
[...]