The Munin plugin


A Munin plugin is a simple executable invoked in a command line environment whose role is to gather a set of facts on a host and present them in a format Munin can use.

A plugin is usually called without any arguments. In this circumstance, the plugin returns the data in a ‘key value’ format. For example, the ‘load’ plugin, which comes standard with Munin, will output the current system load:

# munin-run load
load.value 0.03

All plugins must also support the argument ‘config’ to get metadata on the plugin:

# munin-run load config
graph_title Load average
graph_args --base 1000 -l 0
graph_vlabel load
graph_scale no
graph_category system
load.label load
graph_info The load average of the machine describes how many processes are in the run-queue (scheduled to run "immediately"). 5 minute load average

Plugins may support other arguments, but the two cases described above will work for any plugin.