Overview
========

To use the nagios resources, activate storeconfigs on the puppetmaster.

Monitor
-------

On one node the "nagios" class has to be included. This installs nagios and
apache and configures the cgi on http://node/nagios/


Hosts
-----

On a node which shall be monitored with nagios, include the "nagios::target".
This just creates a host declaration for this hosts "$fqdn".
Set the $nagios_parent variable in the node scope for enabling the reachability
features of nagios. If a node needs more customisation, use the
"nagios::host" component directly.

To monitor hosts not managed by puppet, add "nagios::extra_host"s to the
monitoring node. These can be used as intermediate $nagios_parent's


Services
--------

Services can be monitored by using the "nagios::service" component.

The simplest form is::

	nagios::service { check_dns: }

The intention being obviously to put such declarations into a component defining
a service, thereby being automatically applied together with all instances of
the service.



Caveats
=======


Performance
-----------

A major drawback is that currently the needed storeconfig setting and
subsequent filling of the database is really a drag on performance. 0.22.1
for example breaks at approximatly 120 monitored services (depends on H/W of
course). 0.22.3 has improved that my a factor of 3-4. 


Consistency/Validation/Verification
-----------------------------------

After convergance of the configuration, the system is obviously consistent.
That is, all defined services are monitored. The problem is though, that it is
neither automatically valid - it is not guaranteed that all components declare a
nagios::service - and even if the configuration is valid it definitly is
unverified, since that is always a judgment call for an external observer.



Examples
========

Usage example::

node nagios {

	include nagios

	# Declare another nagios command
	nagios::command { http_port: command_line
=> '/usr/lib/nagios/plugins/check_http -p $ARG1$ -H $HOSTADDRESS$ -I
$HOSTADDRESS$'

	# Declare unmanaged hosts
	nagios_extra_host {
        	"router01":
                	parent => "gateway",
                	ip => "10.0.0.1";
        	"router02":
                	parent => "router01",
                	ip => "192.168.0.1";
	}

}


node target {

	# Monitor this host
	$nagios_parent = "router01"
	include nagios_target

	# monitor a service
	$apache2_port = 8080
	include apache

	# The apache class actually does this somewhere:
	#nagios::service { "http_${apache2_port}":
	#       check_command => "http_port!${apache2_port}"
	#}
	# which goes via export/collect to the nagios node.

}


License
=======

Copyright (C) 2007 David Schmitt <[email protected]>
See the file LICENSE in the top directory for the full license.