Munin plugin scripts

A single plugin file defines (multiple) graphs by subclassing the bases as mentioned in the next section. The main function uses the called script’s filename to determine which of the defined graphs is relevant.

Data for each graph is determined by retrieving a text file from a URL (with possibly given basic authentication data).

The format for the data is plain/text wich each line having key/value pairs split by ‘:’. The values are expected to be floats.

All graph bases expect two environment variables to be set:

URL

The URL at which to retrieve data from. Must include a ‘%s’ which encodes the graph name.

AUTH

HTTP basic authentication information. Either empty or in the form of ‘username:password’.

The environment variables can be configured using munin’s plugin-conf.d like this:

The plugin is called prefix_something_1:

[prefix_*]
env.URL http://foo:8900/myapp/munin?data=%s
env.AUTH admin:admin

Graph bases

The following base classes are currently defined:

SimpleGraph

A simple graph with a single value that is plotted as an absolute value.

SimpleMultiGraph

Multiple absolute values plotted on the same graph and scale.

more bases will be added as needed.

Main function

The main function handles munin-typical type_option_index symlink scripts by looking at the name from which the main script was called.

Example script

Here’s a sample script that you could symlink into the plugins directory:

from gocept.munin.client import SimpleGraph, main

class people(SimpleGraph):
    name = key = 'people'
    title = 'How many people are there?'
    category = 'Office'

main()