This repository contains a simple Python script which can be used to export data from Munin's raw RRD files to a JSON format suitable for use with the line and bar graphs of Panic Inc's iPad Status Board 2 app. If you already have a server on which you use Munin to monitor its status, therefore, you can trivially get that data live updating on your iPad along with all the other views that Status Board 2 supports.
The code is all contained in a single script, munin-to-status-board.py,
which you can install anywhere you fancy. This script expects one or
more configuration files as its parameters which specify the source RRD
files to use and also the graphs to generate. Typically you'll execute this
via a crontab entry like this:
*/5 * * * * /path/to/munin-to-status-board.py /path/to/config.cfg
See the later Configuration section for creating the configuration file.
The configuration file specifies where the output JSON files are to be
generated -- this should be in the web root of your favourite webserver,
the configuration of which is outside the scope of these instructions. If
you're just serving small static content I recommend nginx, but since all
that's required is serving static content then more or less any webserver
should be more than sufficient, even Python's own
SimpleHTTPServer.
I strongly recommend confirming that this file is generating and looks at least approximately correct before attempting to set up the iPad app -- this makes it easier to debug any issues.
On the iPad app you just need to add a widget of type Graph and in the configuration for it enter the full URL to the JSON file generated by the script. All other configuration for it should be automatic.
The configuration can be split across as many files as you like -- the
contents of all those specified on the command-line will be merged. The
basic syntax is that expected by Python's ConfigParser module, which is
similar to the Windows .ini file format.
The file is split into sections specified by a heading in square brackets.
Each section specifies either a data source or a graph, and there is a special
settings section which currently just contains logging configuration.
An annotated sample configuration is shown below to demonstrate the available settings:
[DEFAULT]
# As per Python's ConfigParser module, the DEFAULT section can be used
# to provide default values for other sections and also names to be
# substituted in as part of other settings with syntax %(value)s.
srcprefix: /var/lib/munin/com/example.com
webroot: /var/lib/www/dashboard
logroot: /var/log
[settings]
# If specified, logging will be performed to the named file. If not,
# logging will be done to stderr. If --debug is specified, stderr logging
# will be done separately and in addition to logging to this file.
logfile: %(logroot)s/munintostatus.log
# Should be one of CRITICAL, ERROR, WARNING, INFO and DEBUG - this affects
# the level of logging into the log file.
# Default is INFO.
loglevel: INFO
# A section starting with the word "source" defines a source - the rest
# of the name is arbitrary but is used in later "graph" sections to
# tie sources into graphs.
[source net-traffic-up]
# The title of the data set in the graph legend.
title: TX
# The path of the RRD file to populate this data source.
source-file: %(srcprefix)s-if_venet0-up-d.rrd
# Optionally force the colour of the line on the graph, for choices see
# https://library.panic.com/status-board/graph_tutorial/#color
# Default is to allow status board to pick the colours.
color: green
[source net-traffic-down]
title: RX
source-file: %(srcprefix)s-if_venet0-down-d.rrd
color: red
# A section starting with the word "graph" defines a graph - the rest
# of the name is arbitrary and is currently not used anywhere.
[graph net-traffic]
# The title of the whole graph.
title: Net Traffic (bit/s)
# Optionally set scale to "K" or "M", which will cause the graph to scale
# values to thousands or millions respectively, and also cause the K
# or M suffix to be added to values on the y-axis.
scale: K
# Specify type of graph, either "line" or "bar".
# Default is "line".
type: line
# The full path of the generated JSON text file.
output-file: %(webroot)s/network.json
# The interval at which the status board should re-fetch the JSON file.
# Defaults to whatever "resolution" is set to.
refresh-every: 5m
# The interval between data points in the generated set.
# Default is 5m.
resolution: 5m
# The period of time over which to return data - the combination of
# this and 'resolution' determines the number of data points.
# Default is 24h.
period: 6h
# A comma-separated list of the names of sources defined by earlier
# "source" sections. Each of these sources will become one data set
# shown on the graph.
sources: net-traffic-up, net-traffic-down
If you have any questions then feel free to get in touch, I'll help however I can. The whole thing is quite simple, however, so you might find you get a faster response just reading the code yourself.