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 and on Debian.

For examples how to use this class see the example/ directory.

Server

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

• Use check_mk::omd_repo to enable a debian repository for omd (requires apt module from i.e. https://labs.riseup.net/code/projects/shared-apt). For now, you need to fetch the omd apt-key manually from http://labs.consol.de/nagios/omd-repository/, put it into your site_apt/files/keys directory and pass the custom_key_dir parameter to the apt class, like

  class { 'apt': custom_key_dir => 'puppet:///modules/site-apt/keys' }

• 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'

omdadmin_htpasswd: changes the htpasswd of the amdadmin user (requires apache module from i.e. https://labs.riseup.net/code/projects/shared-apache)

use_ssh: Configures ssh to agents that use the same parameter. Default: false.

inventory_only_on_changes: By default (parameter set to true) these two execs are called only when config files changes: - Exec['check_mk-refresh'] (which runs a check inventory by calling check_mk -II) - Exec['check_mk-reload'] (which generates the nagios config and reloads nagios by calling check_mk -O) By setting this parameter to false these execs will be called on each puppetrun.

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'

method: "xinetd" (default) or "ssh" "ssh": Use ssh instead of the tcp wrapper in order to allows the server to execute the agent on the client.

generate_sshkey: true or false (default)

       * Deploys ssh keypair on server (in /opt/omd/sites/monitoring/.ssh)
       * Saves keypair on puppetmaster (/etc/puppet/modules/keys/files/check_mk_keys by default)
       * Deploys public key on client in /root/.ssh/authorized_keys (restricting allows command to "/usr/bin/check_mk_agent")

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 are not automatically added to the all_hosts list in main.mk. To manually include these hosts you can add them to '/omd/sites/monitoring/etc/check_mk/all_hosts_static' (replacing 'monitoring' with your site name). Use the quoted fully qualified domain name with a two-space prefix and a comma suffix - for example:

  'host1.domain',
  'host2.domain',

You can also include host tags - for example:

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

Remember to run the Puppet agent on your monitoring host to pick up any changes.

Migrating from nagios-statd

nagios-statd provides several features that can be replaced with check_mk plugins.

nagios-stat-proc: checks processes on the agent system If you previously used the nagios puppet module to do something like:

   check_command => 'nagios-stat-proc!/usr/sbin/foo!1!1!proc'

you can now use the check_mk ps check:

   check_mk::agent::ps {
     'foo':
       procname => '/usr/local/weirdpath/foo',
       levels => '1, 2, 2, 3',
       owner => 'alice'
   }

defaults: procname: "/usr/sbin/${name}" levels: '1, 1, 1, 1' owner: not required

Run check_mk with '-M ps' for the manpage explaining the parameters.

swap: check_mk has a 'mem.used' check which is enabled by default. But as it's manpage explains if you want to measure swappiness you are better off using the 'kernel' check and measuring 'Major Page Faults' (pgmajfault).

disk: check_mk has a 'df' check which is enabled by default.

Migrating from nrpe to mrpe

If you were using nrpe to run a nagios plugin locally, first check if a native check_mk check exists with the same functionality, if not consider writing one. But if continuing to use the nagios plugin makes sense you can switch to mrpe.

• Continue to deliver the plugin to the agent system

• include check_mk::agent::mrpe

• add a line to the mrpe.cfg file using augeas

   augeas {
     "Foo":
       incl    => '/etc/check_mk/mrpe.cfg',
       lens    => 'Spacevars.lns',
       changes => 'set FOO /usr/local/lib/nagios/plugins/check_foo',
       require => [ File['/usr/local/lib/nagios/plugins' ], Package['check-mk-agent'] ];
   }
  

This is the riseup clone, available at:

git://labs.riseup.net/module_check_mk