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Description

Check_MK is described as a general purpose Nagios-plugin for retrieving data. This cookbook aims to be the definitive cookbook for check_mk.

Check_MK and Nagios are both file configured and as such, have configuration shortcuts like host_groups (Nagios) and tags (Check_MK). This cookbook considers these types of configuration variables as a human interface, so in most cases you'll see duplicated settings. For example, when configuring custom checks in a role, these checks will be configured for each host separately.

This cookbook does not depend on the Nagios cookbook since it tries to do too much. Instead, it is treated as a backend and configured in a minimalistic fashion.

Most of the attributes correspond to the values that are expected from that packages.

Requirements

Platform

Currently supported platforms

• Ubuntu >= 10.04
• Debian >= 6.0.0

Platforms to be supported (TODO)

• Red Hat branch

Cookbooks

• apache2
• fewbytes-common
• xinetd
• ark
• sudo

Attributes

Default attributes

The cookbook attributes

• node["check_mk"]["server"]["package"]["name"] - Check_MK package name (Default: check_mk)

• node["check_mk"]["server"]["package"]["version"] - Version

• node["check_mk"]["server"]["package"]["filename"] - Package file name

• node["check_mk"]["server"]["package"]["url"] - Download URL

• node["check_mk"]["server"]["package"]["checksum"] - Downloaded file checksum (sha256)

• node["check_mk"]["server"]["user"] - Nagios user name (Default: nagios)

• node["check_mk"]["server"]["group"] - Nagios group (Default: nagios)

• node["check_mk"]["server"]["conf"]["dir"] - Check_MK configuration directory (Default /etc/check_mk)

• node["check_mk"]["server"]["conf"]["main"] - Check_MK main configuration file (Default: /etc/check_mk/main.mk)

• node["check_mk"]["server"]["conf"]["multisite"] - Check_MK Multisite configuration file (Default: /etc/check_mk/multisite.mk)

• node["check_mk"]["server"]["conf"]["unix_socket"] - Nagios and Check_MK unix socket (Default: /var/log/nagios/rw/live)

• node["check_mk"]["nagios"]["conf.d"] - Nagios configuration directory

• node["check_mk"]["nagios"]["conf"] - Nagios main config file (Default: /etc/nagios3/nagios.cfg)

• node["check_mk"]["nagios"]["cgi"] - Nagios cgi config file (Default: /etc/nagios3/cgi.cfg)

• node["check_mk"]["nagios"]["command_file"] - Nagios command file (Default: /var/log/nagios/rw/nagios.cmd)

• node["check_mk"]["nagios"]["plugins_dir"] - Nagios plugins directory, used primarily to target plugins from the agent (MRPE) (Default: /usr/lib/nagios/plugins)

• node["check_mk"]["nagios"]["extra_plugins"] - Install nagios' extra plugins or not (Default: true)

• node["check_mk"]["nagios"]["extra_plugins_package"] - The extra plugins package name

• node["check_mk"]["www"]["auth"] - CGI auth file (Default: /etc/nagios3/htpasswd.users)

• node["check_mk"]["www"]["user"] - Webserver user (Default: www-data)

• node["check_mk"]["www"]["group"] - Webserver group (Default: www-data)

• node["check_mk"]["www"]["conf"] - Check_MK webserver config file (Default: /etc/apache2/conf.d/zzz_check_mk.conf)

Optional node attributes

Check_MK configuration variables attributes

Check_MK server config related attributes

These attributes configure global variables of the main.mk file.

TODO: !

Check_MK hosts attributes

These attributes configure various related variables per host. On some of them, you'll see a hash with keys called pXX, only their values are used (this is due to how chef treats arrays in Attribute#deep_merge). One advantage is that you can override a certain parameter from a different attribute set. Each attribute corresponds a variable in the list of configuration variables of Check_MK.

checks

'check_mk': {
    'config': {
        'checks': {
            'check_type': {
                'check_name': {
                    'p01': '/usr/sbin/sshd',
                    'p02': '1',
                    'p03': '1',
                    'p04': '1',
                    'p05': '1'
                }
            }
        }
    }
}

• check_type - The check type, like ps or ps.perf.
• check_name - The check as will be seen in Nagios (Check_MK).
• Last level of attributes are the check parameters (only values are used). This structure is used to enable overriding specific values from high-level attributes.

check_parameters

'check_mk': {
    'config': {
        'check_parameters': {
            'service_pattern': 'parameters'
        }
    }
}

• service_pattern - The service pattern as explained on Check_MK documentation.
• parameters - Taken as is and placed as the first item in the check_parameters tuple.

extra_service_conf

'check_mk': {
    'config': {
        'extra_service_conf': {
            'service_name': {
                'active_checks_enabled': '0',
                'is_volatile': '1'
            }
        }
    }
}

Hash of key value pairs for configuration variables that will be attached to this service check.

• service_name - The service name as Nagios sees it

legacy_checks

'check_mk': {
    'config': {
        'legacy_checks': {
            'check_name': {
                'performance': "True",
                'command': "/bin/echo I am a passive check only",
                'extra_service_conf': {
                    'active_checks_enabled': '0'
                }
            }
        }
    }
}

• check_name - The service name
• performance - Flag for a performance check or not (Default: False). See legacy checks page.
• extra_service_conf - Same as extra_service_conf above, but applied to this legacy check specifically.

Forcibally ignoring a node from Check_MK

'check_mk': {
    'ignore': true
}

Pseudo agents configuration

Many times you have some external device or a port on a load-balancer you'd like to monitor, in which case you cannot use the agent recipe. For this you can use psuedo agents through the check_mk data bag.

Pseudo agents are node-like attribute structures configured in a data bag item. The cookbook only looks at the structure which is relevant for registering the agent on Check_MK. By duplicating the relevant structure, we try to make it easier to remember or transfer some configuration from a node/role to a data bag item.

The server recipe looks for items in the data bag check_mk, with the pseudo_agents usage on the same chef_environment. The exact search call is search(:check_mk, "usage:pseudo_agents AND chef_environment:#{node.chef_environment}").

An example for a data bag item

{
    'id': 'some data bag item id',
    'usage': [
        'pseudo_agents'
    ],
    'chef_environment': [
        '_default'
    ],
    'agents': {
        'arbitrary.agent.name': {
            'fqdn': "somehost.somedomain",
            'ipv4': "ip.add.re.ss",
            'check_mk': {
                'tags': ["sometag"],
                'config': {
                    'legacy_checks': {
                        'Load balancer': {
                            'command': "$USER1$/check_http ..."
                            'performance': "False"
                        }
                    }
                }
            }
        },
        'another.agent': {
            # ...
        }
    }
}

• usage - Required to contain pseudo_agents so it would be returned by the search query.
• chef_environment - Must contain the same environment value like the server.
• agents - The recipe looks for agents under this key.
  • arbitrary.agent.name - Could be any legal data bag item key, not used by cookbook.
    • fqdn - Required. This is how the cookbook chooses the host name.
    • ipv4 - Optional. Normally, the cookbook tries to find the best ip address to use, but since this is not a real node you must supply a real IP address (or hostname) if fqdn cannot be resolved.
    • check_mk - An attribute tree which is treated exactly as it would be in a node's attributes.

External agents configuration

External agents are treated the same as peudo agents with a small difference. Pseudo agents are expected to be non-inventorizable, external agents are treated as normal Check_MK agents.

This falls under the use-case where you want to monitor hosts that are not part of the Chef cluster. Such nodes need minimal configuration as they will be inventorized by Check_MK.

The following is a simple example of an external agent data bag item.

{
    'id': 'some data bag item id',
    'usage': [
        'external_agents'
    ],
    'chef_environment': [
        '_default'
    ],
    'agents': {
        'arbitrary.agent.name': {
            'fqdn': "somehost.somedomain",
            'ipv4': "ip.add.re.ss",
            'check_mk': {
                'tags': ["sometag"]
            }
        },
        'another.agent': {
            # ...
        }
    }
}

Usage

Resources

check_mk_mrpe_plugin

The check_mk_mrpe_plugin adds a new MRPE plugin and creates the mrpe.cfg if needed.
Check_MK treats MRPE plugins like NRPE plugin, so any Nagios plugin can be used.

check_mk_mrpe_plugin "<plugin_name>"
    plugin "<plugin_name>"
    path "/path/to/plugin/executable"
    arguments "-H 127.0.0.1 --foo bar"
end

Configuration variables not yet implemented

• agent_ports
• dyndns_hosts
• ping_levels
• check_periods
• extra_host_conf (see legacy_checks implementation)
• ignored_services
• ignored_checks
• snmp_communities
• snmp_hosts
• snmp_ports