ansible-collection-prometheus/roles/prometheus/tasks/prometheus.yml

---

- name: create config fragment directory
  delegate_to: localhost
  run_once: yes
  file:
    path: "{{ playbook_dir }}/.prometheus/{{ item }}.d"
    state: directory
  loop:
    - conf
    - alerts

- name: list current config fragments
  delegate_to: localhost
  find:
    paths:
      - "{{ playbook_dir }}/.prometheus/conf.d/"
      - "{{ playbook_dir }}/.prometheus/alerts.d/"
    recurse: yes
    patterns: "*.yml"
    excludes: "00-base.yml"
  register: prometheus_register_current_fragments

- name: process current config fragments
  set_fact:
    prometheus_register_current_fragments:
      "{{ prometheus_register_current_fragments.files | map(attribute='path') | list }}"

- name: render prometheus base config
  delegate_to: localhost
  run_once: yes
  template:
    src: prometheus-base.yml
    dest: "{{ playbook_dir }}/.prometheus/conf.d/00-base.yml"

- name: render prometheus job configs
  delegate_to: localhost
  run_once: yes
  template:
    src: prometheus-job.yml
    dest: "{{ playbook_dir }}/.prometheus/conf.d/{{ '%02d' | format(counter+1) }}-job-{{ item.name }}.yml"
  vars:
    job: "{{ item }}"
  loop: "{{ hostvars[inventory_hostname] | dict2items | selectattr('key', 'match', '^prometheus_job_.+$') | map(attribute='value') | list }}"
  loop_control:
    index_var: counter
  register: prometheus_register_new_config_fragments

- name: remove newly created files from deletion list
  set_fact:
    prometheus_register_current_fragments:
      "{{ prometheus_register_current_fragments | difference(prometheus_register_new_config_fragments.results | map(attribute='dest') | list) }}"

- name: render prometheus alert base config
  delegate_to: localhost
  run_once: yes
  template:
    src: prometheus-alert-base.yml
    dest: .prometheus/alerts.d/00-base.yml

- name: render prometheus alert configs
  delegate_to: localhost
  run_once: yes
  copy:
    content: "{{ item.alerts | to_nice_yaml(indent=2) | indent(2, first=true) }}"
    dest: "{{ playbook_dir }}/.prometheus/alerts.d/{{ '%02d' | format(counter+1) }}-alert-{{ item.name }}.yml"
  loop: "{{ hostvars[inventory_hostname] | dict2items | selectattr('key', 'match', '^prometheus_job_.+$') | map(attribute='value') | list }}"
  loop_control:
    index_var: counter
  register: prometheus_register_new_alert_fragments

- name: remove newly created files from deletion list
  set_fact:
    prometheus_register_current_fragments:
      "{{ prometheus_register_current_fragments | difference(prometheus_register_new_alert_fragments.results | map(attribute='dest') | list) }}"

- name: render host-specific prometheus alert configs
  delegate_to: localhost
  copy:
    content: "{{  hostvars[item].prometheus_host_specific_alerts | to_nice_yaml(indent=2) | indent(2, first=true) }}"
    dest: "{{ playbook_dir }}/.prometheus/alerts.d/{{ '99-host-%s' | format(hostvars[item].inventory_hostname) }}-alerts.yml"
  when: "'prometheus_host_specific_alerts' in hostvars[item]"
  loop: "{{ hostvars.keys() | list }}"
  register: prometheus_register_new_host_specific_alert_fragments

- name: remove newly created files from deletion list
  set_fact:
    prometheus_register_current_fragments:
      "{{ prometheus_register_current_fragments | difference(prometheus_register_new_host_specific_alert_fragments.results | selectattr('dest', 'defined') | map(attribute='dest') | list) }}"  # noqa 204

- name: delete old config fragments
  delegate_to: localhost
  file:
    path: "{{ item }}"
    state: absent
  loop: "{{ prometheus_register_current_fragments }}"

- name: assemble fragment directories
  delegate_to: localhost
  assemble:
    src: "{{ playbook_dir }}/.prometheus/{{ item.local }}.d/"
    dest: "{{ playbook_dir }}/.prometheus/{{ item.remote }}.yml"
    delimiter: "\n\n"
  loop:
    - local: conf
      remote: prometheus
    - local: alerts
      remote: alert_rules

- name: upload config files to host
  copy:
    src: "{{ playbook_dir }}/.prometheus/prometheus.yml"
    dest: "/etc/prometheus/prometheus.yml"
    owner: root
    group: root
    mode: 0644
    validate: /usr/bin/promtool check config %s
  notify: restart prometheus

- name: upload alert config file to host
  copy:
    src: "{{ playbook_dir }}/.prometheus/alert_rules.yml"
    dest: "/etc/prometheus/alert_rules.yml"
    owner: root
    group: root
    mode: 0644
    validate: /usr/bin/promtool check rules %s
  notify: restart prometheus

- name: configure prometheus lookback delta
  lineinfile:
    path: /etc/default/prometheus
    regexp: "^ARGS=.*$"
    line: >-
      ARGS="--query.lookback-delta={{ prometheus_lookback_delta }}"      
    insertbefore: BOF
  notify: restart prometheus