.. link:
.. description: is a tiny munin-node implementation for FreeBSD written in pure bourne shell providing basic plugin support.
.. tags: project
.. date: 2015/02/01 19:10:08
.. title: minimunin
.. subtitle: A tiny munin-node implementation for FreeBSD written in pure bourne shell providing basic plugin support
.. slug: ../arts/software/minimunin/index
.. prio: 800

.. contents::
  :depth: 1
  :class: ezjail-toc

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.. image:: /arts/software/minimunin/minimunin.png
  :align: center

Overview
========

`munin <http://munin-monitoring.org/>`_ is an open source multi platform service monitoring framework, written in perl. Munin nodes report server statistics to their respective masters. Unfortunally, the munin-node script is written in perl, too – even though the language features never actually are used. On a FreeBSD system this introduces unnecessary dependencies. *minimunin* tries to address this: It was implemented as a simple shell script triggered from inetd.conf and comes with some handy built in monitoring commands. Most of the munin plugins should also work.

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Code
====

.. image:: http://www.freebsd.org/gifs/daemon_hammer-tn25.jpg
  :align: right

You can always get the latest version of *minimunin*, use ``git clone git://erdgeist.org/minimunin`` or the legacy view ``cvs -d :pserver:anoncvs@cvs.erdgeist.org:/home/cvsroot co minimunin`` with an empty password to check it out. There is a `minimunin tarball <minimunin-0.2.tar.bz2>`_. You can scroll through the source at `minimunin gitweb </gitweb/minimunin>`_ or `minimunin cvsweb (deprecated) </cvsweb/minimunin>`_. Typing ``make install`` installs the binary in your ``${PREFIX}/bin`` (or ``/usr/local``, if none is set).

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Installation
============

After getting *minimunin* either from source or by installing the FreeBSD port/package, you need to activate *minimunin*. Just add the line::

  munin stream tcp nowait nobody /usr/libexec/tcpd /usr/local/bin/minimunin

to your ``/etc/inetd.conf``. Alternatively, if you plan to run plugins that require root permissions (e.g. for changing to a different user via the plugin config), add::

  munin stream tcp nowait root /usr/libexec/tcpd /usr/local/bin/minimunin

to your ``/etc/inetd.conf``.

In both cases you need to enable inetd by setting ``inetd_enable="YES"`` in your ``/etc/rc.conf`` and restart inetd with the ``service inetd start`` command. You may also want to restrict access to your munin node via the ``/etc/hosts.allow`` and ``/etc/hosts.deny`` configuration files.

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Plugins
=======

Munin has been designed to allow administrators to `write their own plugins <http://munin-monitoring.org/wiki/HowToWritePlugins>`_ to provide statistics not covered by the base installation. You can find `many munin plugins here <http://munin-monitoring.org/browser/munin-contrib/plugins>`_. *minimunin* can execute those plugins, as well. It expects plugin files in the folder /usr/local/etc/minimunin-plugins and will ignore `wild card plugins <http://munin-monitoring.org/wiki/WildcardPlugins>`_. In order to use them (after reading the documentation on the project website ;) create the appropriate soft link, e.g. ``ln -s if_ /usr/local/etc/minimunin-plugins/if_bge0``. Please note that the plugins must be executable and you may need to install further dependencies for plugins, such as perl, python or monitoring helpers.

munin plugins `can be configured with ini-file style config files <http://munin-monitoring.org/wiki/plugin-conf.d>`_. *minimunin* expects config to reside under ``/usr/local/etc/minimunin-configs``, either as a single config file or a directory containing respective configs. Currently *minimunin* only supports the config parameters ``env.``-variables, ``user`` and ``command``. The ``group`` and ``timeout`` config parameters are not supported. The ``user`` parameter only works if *minimunin* finds itself being root and otherwise silently ignores the ``user`` parameter.

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Version history
===============

* V0.2 `minimunin-0.2.tar.bz2 <minimunin-0.2.tar.bz2>`_ (2014-13-02)

  * Fixed a bug where uptime was not reported correctly. Thanks to Lothar Schmidt.
  * Fixed a bug where only the last environment setting of a plugin config was obeyed. Thanks to Philipp Wünsche.
* V0.1 `minimunin-0.1.tar.bz2 <minimunin-0.1.tar.bz2>`_ (2013-09-29)

  * First version, no diffs to previous ones ;)

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License
=======

*minimunin* was written by `Dirk Engling <mailto:erdgeist@erdgeist.org>`_ and is considered `beer ware </beerware.html>`_.

Please do not even think about hesitating to contact me via email or `@erdgeist <http://twitter.com/erdgeist>`_ on twitter.