Introduction/Notes

This modules was inspired and based on the work of David Schmitt The immerda project group adapted and improved this module. Mainly we made it using the new native puppet nagios commands as well we made it more modular to fit for multidistro usage.

In it's current form, this module can be used on CentOS and Debian.

Overview

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

You need to be running verison 0.25 or later of puppet.

Monitor

On one node the nagios class has to be included. By default this installs apache using the apache module. To use lighttpd instead, include "nagios::lighttpd", or, if the web server is not to be managed by puppet, include "nagios::headless".

Hosts

On a node which shall be monitored with nagios, include the "nagios::target". This just creates a host declaration for this host's $::ipaddress fact. If the $::ipaddress of your target is not the one you wish to modify, you can use nagios::target::fqdn instead, which will use the $::fqdn fact of the host instead.

Pass the $parents variable to the target class for enabling the reachability features of nagios. If a node needs more customisation, use the native @@nagios_host type directly (the double-ampersand declares the object as an exported resource).

To monitor hosts not managed by puppet, add nagios_host objects to the monitoring node. The required parameters are alias, address and use. If you don't specify a proper nagios template with the use parameter, some extra parameters are needed. You may look up the nagios documentation for this.

Services

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

The simplest form is:

nagios::service { 'check_http':
    check_command => 'http_port!80',
}

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.

Obviously, the check command must either be defined using nagios_command objects (some are supplied in nagios::defaults::commands) or in the nagios configuration files directly.

NRPE Services

Some Nagios services need to be checked via NRPE. The following will make the nagios server define a service that will check the NRPE command check_cpu on the current node:

nagios::service { 'CPU Usage':
  use_nrpe => 'true',
  check_command => "check_cpu",
  nrpe_args => "-t 60"
}

NRPE Commands

To be able to call NRPE commands on a host, one needs to define that command and what it is going to execute:

nagios::nrpe::command { 'debsums':
  check_command => '/usr/lib/nagios/plugins/check_debsums openssh-server'
}

Upgrade Notes

The nagios::target bits have been reworked, the notable changes that may affect an upgrade are:

• previous versions had nagios::target::nat which used the $::fqdn for the address part of nagios::target, this has been renamed to nagios::target::fqdn to be more clear. if you were using nagios::target::nat then you will need to change those references to ::fqdn

• previous versions of this module used $::fqdn for the nagios::target address, now it is using $::ipaddress. If you need $::fqdn, use nagios::target::fqdn instead of nagios::target

• previous versions of nagios_host used the parameter named ip, that has been changed to address

IRC bot

Notifications can easily be sent to an IRC channel by using a bot. To do so, simply include nagios::irc_bot on the nagios server and define the right $nagios_nsa_* variables (see the 'Variables' section below).

You can then use the notification commands notify-by-irc and host-notify-by-irc with service and host definitions to make them report state changes over IRC.

Caveats

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.

Removal of nagios objects

This module does not automatically purge nagios objects such as hosts and services that become absent from the manifests. One must set ensure => absent to guarantee the removal of nagios objects from the configuration as desired.

Templates not supported using native types

Templates of hosts and services cannot yet be defined using native types. In this module, they are provided using a file resource by the class nagios::defaults::templates

See : http://projects.reductivelabs.com/issues/1180

Variables

Options to change the behavior of the nagios class:

• allow_external_cmd: Set to true, if you'd like to ensure that your http daemon can write to the external command file. You may also need to flip check_external_commands in nagios.cfg to enable this functionality.

For the irc_bot class:

• nsa_socket: This optional variable can be used to specify the path to the socket file that the IRC daemon should use.

• nsa_server: When using the IRC bot, this defines the server address of the IRC network on which the bot will connect.

• nsa_port: Defines the port number on the IRC server on which the bot should connect. When this variable is not set, the port used by default is 6667.

• nsa_nickname: This is the nickname that the IRC bot will take.

• nsa_password: Some networks require a password to connect to them. This defines such a password.

• nsa_channel: The name of the channel that the IRC bot will join and will post notifications to.

• nsa_pidfile: This optional variable can be used to define the path to the file that will contain the process ID of the IRC bot daemon.

• nsa_realname: The IRC bot user's real name that will be displayed. By default, the real name is 'Nagios'.

• nsa_usenotices: The IRC bot will by default "say" to the channel the nagios message, but you can switch this variable to 'notice' if you would prefer them to be sent as IRC NOTICE messages.

PNP4Nagios integration

For PNP4Nagios integration information, please see README.pnp4nagios

Examples

Usage example:

node nagios {

include nagios::apache
include nagios::defaults

    # 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_host {
	    'router01.mydomain.com':
		    alias => 'router01',
		notes => 'MyDomain Gateway',
		address => "10.0.0.1",
		use => 'generic-host';
	    "router02.mydomain.com":
		alias => 'router02',
		    address => '192.168.0.1',
		    parents => 'router01',
		use => 'generic-host';
    }

 }


  node target {

  # Monitor this host
  class{'nagios::target':
    parents = 'router01'
  }

  # monitor a service
  $apache2_port = 8080
  include apache2

  # This actually does this somewhere:
  #nagios::service { "http_${apache2_port}":
  #       check_command => "http_port!${apache2_port}"
  #}

  }

TODO

• Provide a default http vhost
• Add facility to deploy nagios plugins
• Add more useful commands and services
• When Puppet will support them, supply nagios templates using native types

License

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

Copyright (C) 2010 Riseup Networks [email protected]