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 <david@schmitt.edv-bus.at>
See the file LICENSE in the top directory for the full license.