ansible/roles/prometheus/tasks/main.yml

---
- name: Install Prometheus
  apt:
    update_cache: true
    name:
      - prometheus
      - prometheus-snmp-exporter
  register: apt_result
  retries: 3
  until: apt_result is succeeded

- name: Configure Prometheus
  template:
    src: prometheus/prometheus.yml.j2
    dest: /etc/prometheus/prometheus.yml
  notify: Restart Prometheus

- name: Configure Prometheus alert rules
  template:
    src: "prometheus/{{ item }}.j2"
    dest: "/etc/prometheus/{{ item }}"
  notify: Restart Prometheus
  loop:
    - alert.rules.yml
    - django.rules.yml

- name: Make Prometheus snmp-exporter listen on localhost only
  lineinfile:
    path: /etc/default/prometheus-snmp-exporter
    regexp: '^ARGS='
    line: "ARGS=\"--web.listen-address=127.0.0.1:9116\""
  notify: Restart prometheus-snmp-exporter

# This file store SNMP OIDs
- name: Configure Prometheus snmp-exporter
  template:
    src: "prometheus/snmp.yml.j2"
    dest: "/etc/prometheus/snmp.yml"
    mode: 0600
    owner: prometheus
  notify: Restart prometheus-snmp-exporter

# We don't need to restart Prometheus when updating nodes
- name: Configure Prometheus nodes
  copy:
    content: "{{ prometheus_targets | to_nice_json }}"
    dest: /etc/prometheus/targets.json

# We don't need to restart Prometheus when updating nodes
- name: Configure Prometheus Ubiquity Unifi SNMP devices
  copy:
    content: "{{ prometheus_unifi_snmp_targets | to_nice_json }}"
    dest: /etc/prometheus/targets_unifi_snmp.json

- name: Activate prometheus service
  systemd:
    name: prometheus
    enabled: true
    state: started

- name: Indicate role in motd
  template:
    src: update-motd.d/05-service.j2
    dest: /etc/update-motd.d/05-prometheus
    mode: 0755