Ansible Role: Monitoring Plugins

This role installs packaged and custom monitoring plugins on RHEL/CentOS and Debian/Ubuntu systems.

Requirements

Root accesss is required for installing packages, so you must run it in a playbook with global root privileges or define become: yes when the role is included.

- hosts: monitored_servers
  roles:
    - role: transitiv.monitoring_plugins
      become: yes

Package Repositories

On CentOS and RHEL the EPEL repository must be enabled in order to install the default packages.

On CentOS 8 the PowerTools repository must also be enabled to install the default packages.

Dependencies

This role has no dependencies.

Variables

monitoring_plugins_install_recommends: true

(Debian/Ubuntu) Defines whether apt installs recommended packages.

# Debian / Ubuntu
monitoring_plugins_packages:
  - monitoring-plugins-standard
  - libmonitoring-plugin-perl
# CentOS / RHEL
monitoring_plugins_packages:
  - perl-Monitoring-Plugin
  - nagios-plugins-all

Defines the packages installed by this role. This variable is "flattened" before it is used so it can contain nested lists if required.

monitoring_plugins_config_file: /etc/monitoring-plugins.ini

Defines the location of an INI file that can be used for the "Extra-Opts" functionality supported by the standard monitoring plugins and plugins utilising the Nagios::Plugin or Monitoring::Plugin Perl libraries. This is useful for passing sensitive information such as passwords to plugins without it being appearing in the command line.

monitoring_plugins_config_user: ''
monitoring_plugins_config_group: ''
monitoring_plugins_config_mode: '0644'

Defines the user, group and permissions of the file specified in monitoring_plugins_config_file.

Note that the default is not secure. If you will be using this functionality then the mode should be set to a minimum of '0640', along with the user and/or group that will be executing the plugins.

monitoring_plugins_custom_directory: /usr/local/lib/nagios/plugins

Defines the destination directory for any custom monitoring plugins. The directory will be created if it does not exist.

monitoring_plugins_custom_directory_user: ''
monitoring_plugins_custom_directory_group: ''
monitoring_plugins_custom_directory_mode: '0755'

Defines the the user, group and permissions of the directory specified in monitoring_plugins_custom_directory.

The default values should be sufficient unless your custom plugins contain sensitive information.

monitoring_plugins_custom_plugins_source_directory: files/monitoring-plugins

Defines the directory on the local filesystem used as the source for custom plugins.

monitoring_plugins_custom_plugins_user: ''
monitoring_plugins_custom_plugins_group: ''
monitoring_plugins_custom_plugins_mode: '0755'

Defines the user, group and permissions of the custom plugins copied into the directory specified in monitoring_plugins_custom_directory.

monitoring_plugins_custom_plugins: []
monitoring_plugins_group_custom_plugins: []
monitoring_plugins_host_custom_plugins: []

Defines the custom plugins that will be copied into the directory specified in monitoring_plugins_custom_directory. The group and host variables can be used to specify additional custom plugins on a group and host specific basis.

Values for entries can either be a plain filename or a hash with the following keys:

• file (required) - defines location of the plugin on the local filesystem (relative to monitoring_plugins_custom_plugins_source_directory)
• name (optional) - defines the filename of the plugin on the host (defaults to the basename of file)
• user (optional) - defines the owner of the plugin on the host
• group (optional) - defines the group of the plugin on the host
• mode (optional) - defines the permissions of the plugin on the host (defaults to monitoring_plugins_custom_plugins_mode)

monitoring_plugins_config: {}
monitoring_plugins_group_config: {}
monitoring_plugins_host_config: {}

Defines the values used to render the file specified in monitoring_plugins_config_file. The format of the file is a 2 level nested hash with the top level key being the name of the group in the INI file and inner hash specifying the keys and values within that group.

Note that the values of the base, group and host variables are merged using the "combine" filter, allowing values to be overridden or extra values to be added on a per group or host basis.

Example

Inventory

[database_servers]
db01

[monitored_servers]
db01

Playbook

- hosts: monitored_servers
  become: yes
  roles:
    - transitiv.monitoring-plugins

Variables

Inside group_vars/all.yml:

monitoring_plugins_config_user: 'nagios'
monitoring_plugins_config_mode: '0640'

monitoring_plugins_custom_plugins:
  - check_linux_memory.pl
  - check_zfs_pool_usage.pl

Inside group_vars/database_servers.yml:

monitoring_plugins_group_custom_plugins:
  - check_mysql_health.pl

monitoring_plugins_group_config:
  check_mysql_health:
    username: monitoring

Inside host_vars/db01.yml:

monitoring_plugins_host_config:
  check_mysql_health:
    database: wordpress
    password: "{{ lookup('password', 'passwords/db01/monitoring' }}"

License

MIT

Author Information

This role was created in 2019 by Transitiv Technologies Ltd.