check_mk

Puppet module for:

• Installing and configuring the Open Monitoring Distribution (OMD) which includes Nagios, check_mk and lots of other tools

• Installing and configuring check_mk agents

Agent hostnames are automatically added to the server all_hosts configuration using stored configs.

Currently only tested on Redhat-like systems.

Server

• Installs omd package either using the system repository (eg. yum, apt) or from a package file retrieved from the Puppet file store

• Populates the all_hosts array in /etc/check_mk/main.mk with hostnames exported by check::agent classes on agent hosts

Example 1

include check_mk

Installs the 'monitoring' package from the system repository. The default 'monitoring' site is used.

Example 2

class { 'check_mk':
  filestore => 'puppet:///files/check_mk',
  package   => 'omd-0.56-rh60-29.x86_64.rpm'
}

Installs the specified omd package after retrieving it from the Puppet file store.

Example 3

class { 'check_mk':
  site => 'acme',
}

Installs the omd package from the system repository. A site called 'acme' is created making the URL http://hostname/acme/check_mk/ running as the 'acme' user.

check_mk parameters

package: The omd package (rpm or deb) to install. Optional.

filestore: The Puppet file store location where the package can be found (eg. 'puppet:///files/check_mk'). Optional.

host_groups: A hash with the host group names as the keys with a list of host tags to match as values. (See 'Host groups and tags' below). Optional.

site: The name of the omd site (and the user/group it runs as). Default: 'monitoring'

workspace: The directory to use to store files used during installation. Default: '/root/check_mk'

Notes

• A user and group with the same value as the site parameter is created. By default this is 'monitoring'.

• The URL is http://yourhostname/sitename/check_mk/ - for example http://monhost.domain/monitoring/check_mk/

• The default username/password is omdadmin/omd. To change this or add additional users log in as the site user and run htpasswd - for example:

  monitoring$ htpasswd -b ~/etc/htpasswd guest guest

• A user called 'guest' is configured as a guest user but is not enabled unless a password is set (as above).

• RedHat-like RPM downloads from http://files.omdistro.org/releases/centos_rhel/

Agent

• Installs the check_mk-agent and check_mk-agent-logwatch packages

• Configures the /etc/xinetd.d/check_mk configuration file

Example 1

include check_mk::agent

Installs the check_mk and check_mk_logwatch packages from the system repository and configures /etc/xinetd.d/check_mk with no IP whitelist restrictions.

Example 2

class { 'check_mk::agent':
  version => '1.2.0p3-1',
  ip_whitelist => [ '10.7.96.21', '10.7.96.22' ],
}

Installs the specified versions of the check_mk and check_mk_logwatch packages after retrieving them from the Puppet file store. Configures /etc/xinetd.d/check_mk so that only the specified IPs (and localhost/127.0.0.1) are allowed to connect.

check_mk::agent parameters

filestore: The Puppet file store location where the packages can be found (eg. 'puppet:///files/check_mk'). Optional.

ip_whitelist: The list of IP addresses that are allowed to retrieve check_mk data. (Note that localhost is always allowed to connect.) By default any IP can connect.

port: The port the check_mk agent listens on. Default: '6556'

server_dir: The directory in which the check_mk_agent executable is located. Default: '/usr/bin'

use_cache: Whether or not to cache the results - useful with redundant monitoring server setups. Default: 'false'

user: The user that the agent runs as. Default: 'root'

version: The version in the check_mk packages - for example if the RPM is 'check_mk-agent-1.2.0p3-1.noarch.rpm' then the version is '1.2.0p3-1'. Only required if a filestore is used.

workspace: The directory to use to store files used during installation. Default: '/root/check_mk'

Host groups and tags

By default check_mk puts all hosts into a group called 'check_mk' but where you have more than a few you will often want your own groups. We can do this by setting host tags on the agents and then configuring host groups on the server side to match hosts with these tags.

For example in the hiera config for your agent hosts you could have:

check_mk::agent::host_tags:
  - '%{osfamily}'

and on the monitoring host you could have:

check_mk::host_groups:
  RedHat:
    description: 'RedHat or_CentOS hosts'
    host_tags:
      - RedHat
  Debian:
    description: 'Debian or Ubuntu_hosts'
    host_tags:
      - Debian
  SuSE:
    description: 'SuSE hosts'
    host_tags:
      - Suse

You can of course have as many host tags as you like. I have custom facts for the server role and the environment type (dev, qa, stage, prod) and define groups based on the role and envtype host tags.

Remember to run the Puppet agent on your agent hosts to export any host tags and run the Puppet agent on the monitoring host to pick up any changes to the host groups.

Static host config

Hosts that do not run Puppet with the check_mk module needs to get added to hiera. check_mk::config creates the config file /omd/sites/monitoring/etc/check_mk/all_hosts_static from a template. The template will look for hiera variables. The hiera variable check_mk::all_hosts_static has to be an array:

check_mk::all_hosts_static:

• host1.domain
• host2.domain

You can also include host tags - for example:

check_mk::all_hosts_static:

• host1.domain|windows|dev,
• host2.domain|windows|prod,

0.3.1:

• Added real world example config

• Fixed RedHat-like RPM URL (thanks #abien)

• Fetch static hosts config from hiera (thanks Martin Alfke)

0.3.0:

• Added host tags to agent config so that host groups can be auto-populated

• Fixed incorrect package name when using a file store that was causing the package existence check to fail always causing an often failing reinstall

• Enable a static list of hosts to be specified for those without the Puppet check_mk module installed

0.2.0:

• Switched to using OMD rather than manually compiling check_mk

• Added support for host tags and creating host groups based on these tags

• Allow local check_mk configuration to be specified in /etc/check_mk/main.mk.local that is appended to /etc/check_mk/main.mk as check_mk can do a lot more than is covered by this module

0.1.1:

• Brown paper bag release to fix a silly typo

0.1:

• Initial release