# The metrics run after apt-daily (update) and apt-daily-upgrade (upgrade), so they show the state apt
# just reached without a timer of their own. The "-" lets a failing metrics run leave apt's units green.
- name: Create the textfile directory
  ansible.builtin.file:
    path: "{{ apt_updates_textfile_dir }}"
    state: directory
    mode: "0755"

- name: Install the apt metrics script
  ansible.builtin.template:
    src: apt-updates-metrics.j2
    dest: /usr/local/sbin/apt-updates-metrics
    mode: "0755"
  register: apt_updates_script

- name: Create the apt timers' drop-in directories
  ansible.builtin.file:
    path: /etc/systemd/system/{{ item }}.service.d
    state: directory
    mode: "0755"
  loop:
    - apt-daily
    - apt-daily-upgrade

- name: Run the apt metrics after the apt timers' services
  ansible.builtin.copy:
    dest: /etc/systemd/system/{{ item }}.service.d/apt-updates-metrics.conf
    mode: "0644"
    content: |
      [Service]
      ExecStartPost=-/usr/local/sbin/apt-updates-metrics
  loop:
    - apt-daily
    - apt-daily-upgrade
  register: apt_updates_dropins

- name: Reload systemd after the apt metrics drop-ins
  ansible.builtin.systemd:
    daemon_reload: true
  when: apt_updates_dropins.changed
  # Check mode does not write the drop-ins.
  ignore_errors: "{{ ansible_check_mode }}"

# Debian's prometheus-node-exporter-apt collector writes apt.prom with the same metric families as this role under
# other HELP texts; node_exporter drops the rows of both files then. This role owns the apt metrics, so the
# collector stays off and its file, also a stale leftover of a removed collector, goes away.
- name: Look for the Debian apt metrics collector
  ansible.builtin.stat:
    path: /lib/systemd/system/prometheus-node-exporter-apt.timer
  register: apt_updates_debian_collector

- name: Stop and disable the Debian apt metrics collector timer
  ansible.builtin.systemd:
    name: prometheus-node-exporter-apt.timer
    enabled: false
    state: stopped
  when: apt_updates_debian_collector.stat.exists

- name: Stop the Debian apt metrics collector service
  ansible.builtin.systemd:
    name: prometheus-node-exporter-apt.service
    state: stopped
  when: apt_updates_debian_collector.stat.exists

- name: Remove the Debian apt metrics collector output
  ansible.builtin.file:
    path: "{{ apt_updates_textfile_dir }}/apt.prom"
    state: absent

# The timers' drop-ins write the metrics after the next apt run; this gives a new host and a changed script
# current metrics at once.
- name: Look for the apt metrics file
  ansible.builtin.stat:
    path: "{{ apt_updates_textfile_dir }}/apt_updates.prom"
  register: apt_updates_prom

- name: Write the apt metrics
  ansible.builtin.command: /usr/local/sbin/apt-updates-metrics
  when: apt_updates_script.changed or not apt_updates_prom.stat.exists
  changed_when: true