Ansible Role: Node Exporter

Role to install (by default) node_exporter on Debian/Ubuntu and EL systems.

Requirements

None per se.

The systemd service file created for node_exporter streams standard output and standard error to syslog and the SyslogIdentifier is set as node_exporter. Hence, you can review node_exporter logs by executing the command sudo journalctl -u node_exporter.service on the system. Additionally, you may wish to configure rsyslog to collect logs with programname node_exporter and output to a specific file for maintaining log files. For log rotation, darkwizard242.logrotate role is available on Ansible Galaxy.

Role Variables

Available variables are listed below (located in defaults/main.yml):

Variables list:

node_exporter_app: node_exporter
node_exporter_version: 1.5.0
node_exporter_osarch: linux-amd64
node_exporter_archive_format: tar.gz
node_exporter_dl_url: "https://github.com/prometheus/{{ node_exporter_app }}/releases/download/v{{ node_exporter_version }}/{{ node_exporter_app }}-{{ node_exporter_version }}.{{ node_exporter_osarch }}.{{ node_exporter_archive_format }}"

node_exporter_app_group: "{{ node_exporter_app }}"
node_exporter_app_group_desired_state: present

node_exporter_app_user: "{{ node_exporter_app }}"
node_exporter_app_user_desired_state: present
node_exporter_app_user_home_state: no
node_exporter_app_user_shell: /bin/false

node_exporter_temp_path: /tmp

node_exporter_bin_path: /usr/local/bin
node_exporter_bin_path_mode: '0755'
node_exporter_bin_path_remote_src: yes

node_exporter_systemd_service_setup: true
node_exporter_systemd_service_name: "{{ node_exporter_app }}"
node_exporter_systemd_service_flags: --collector.systemd --collector.processes --collector.mountstats
node_exporter_systemd_service_template: "{{ node_exporter_app }}.service.j2"
node_exporter_systemd_service_template_dest: "/etc/systemd/system/{{ node_exporter_app }}.service"
node_exporter_systemd_service_template_user: root
node_exporter_systemd_service_template_group: root
node_exporter_systemd_service_template_dest_mode: '0644'
node_exporter_systemd_service_template_backup: yes
node_exporter_systemd_service_desired_state: restarted
node_exporter_systemd_service_desired_boot_enabled: yes

node_exporter_app_port: 9100
node_exporter_app_check_status_code: 200
node_exporter_app_check_status_code_retries: 10
node_exporter_app_check_status_code_delay: 5

Variables table:

Variable	Description
node_exporter_app	Defines the app to install i.e. node_exporter
node_exporter_version	Defined to dynamically fetch the desired version to install. Defaults to: 1.5.0
node_exporter_osarch	Defines os architecture. Used for obtaining the correct type of binaries based on OS System Architecture. Defaults to: linux-amd64
node_exporter_archive_format	Defined to use while downloading the archive.
node_exporter_dl_url	Defines URL to download the node_exporter binary from.
node_exporter_app_group	Name of the group that the node_exporter owner will belong to. Defaults to node_exporter.
node_exporter_app_group_desired_state	present indicates creating the group if it doesn't exist. Alternative is absent.
node_exporter_app_user	Name of the user that node_exporter will be owned by. Defaults to node_exporter.
node_exporter_app_user_desired_state	present indicates creating the user if it doesn't exist. Alternative is absent.
node_exporter_app_user_home_state	Set to 'no' to not create a home directory for node_exporter user.
node_exporter_app_user_shell	Variable is used to define if the user should have a default shell. Set to /bin/false as not required.
node_exporter_temp_path	Temporary path where node_exporter archive is downloaded and extracted.
node_exporter_bin_path	Path in which to place the actual node_exporter in.
node_exporter_bin_path_mode	Permissions for node_exporter binary.
node_exporter_bin_path_remote_src	Defined to let ansible handle unarchive operation on remote hosts.
node_exporter_systemd_service_setup	Utilized as a when condition to setup a systemd service file for node_exporter. If set to false. Systemd service file for node_exporter will be created.
node_exporter_systemd_service_name	Name of the systemd service file when node_exporter_systemd_service_setup is set to true.
node_exporter_systemd_service_flags	Variable to store and pass any commandline flags of node_exporter in it's service file when node_exporter_systemd_service_setup is set to true.
node_exporter_systemd_service_template	Jinja2 source systemd service template file to place on host role is applied on when node_exporter_systemd_service_setup is set to true.
node_exporter_systemd_service_template_dest	Destination filename of node_exporter systemd service when node_exporter_systemd_service_setup is set to true.
node_exporter_systemd_service_template_user	Owner of node_exporter systemd service file when node_exporter_systemd_service_setup is set to true.
node_exporter_systemd_service_template_group	Group of node_exporter systemd service file when node_exporter_systemd_service_setup is set to true.
node_exporter_systemd_service_template_dest_mode	Mode of node_exporter systemd service file when node_exporter_systemd_service_setup is set to true.
node_exporter_systemd_service_template_backup	To backup any existing node_exporter systemd service file when node_exporter_systemd_service_setup is set to true.
node_exporter_systemd_service_desired_state	Desired state of node_exporter systemd service when node_exporter_systemd_service_setup is set to true.
node_exporter_systemd_service_desired_boot_enabled	To set node_exporter service as enabled when node_exporter_systemd_service_setup is set to true.
node_exporter_app_port	As the default port of node_exporter is 9100, this variable is utilized in a handler that checks for whether node_exporter is running on port 9100 or not.
node_exporter_app_check_status_code	Status code that the handler looks for when running the check for node_exporter.
node_exporter_app_check_status_code_retries	Number of times handler tries to check for node_exporter running.
node_exporter_app_check_status_code_delay	Number of time of delays in seconds that the handler waits for in between checks for node_exporter.

Dependencies

None

Example Playbook

For default behaviour of role (i.e. installation of node_exporter) in ansible playbooks.

- hosts: servers
  roles:
    - role: darkwizard242.node_exporter

For customizing behavior of role (i.e. specifying the desired node_exporter version) in ansible playbooks.

- hosts: servers
  roles:
    - role: darkwizard242.node_exporter
      vars:
        node_exporter_version: 1.0.1

For customizing behavior of role (i.e. disabling the setup node_exporter systemd service) in ansible playbooks.

- hosts: servers
  roles:
    - role: darkwizard242.node_exporter
      vars:
        node_exporter_systemd_service_setup: false

License

MIT

Author Information

This role was created by Ali Muhammad.