homelab/ansible/roles/multica_agent_host/tasks/daemon.yml

---
# On Linux `multica daemon autostart enable` writes a systemd *user* unit.
# A user unit does not start at boot unless the user lingers — without this the
# daemon only comes back when someone logs in, which on a headless agent host
# is never.
- name: Daemon | Enable systemd lingering for the daemon user
  ansible.builtin.command:
    argv: ["loginctl", "enable-linger", "{{ multica_user }}"]
    creates: "/var/lib/systemd/linger/{{ multica_user }}"
  become: true
  when:
    - multica_enable_linger | bool
    - multica_autostart | bool

- name: Daemon | Wait for the user's runtime directory
  ansible.builtin.wait_for:
    path: "/run/user/{{ _multica_uid }}"
    state: present
    timeout: 30
  become: true
  when:
    - multica_enable_linger | bool
    - multica_autostart | bool

- name: Daemon | Read the current autostart registration
  ansible.builtin.command:
    argv: "{{ _multica_cmd + ['daemon', 'autostart', 'status'] }}"
  become: true
  become_user: "{{ multica_user }}"
  environment: "{{ _multica_user_env }}"
  register: _multica_autostart_status
  changed_when: false
  failed_when: false
  check_mode: false

- name: Daemon | Register boot autostart
  ansible.builtin.command:
    argv: "{{ _multica_cmd + ['daemon', 'autostart', 'enable'] }}"
  become: true
  become_user: "{{ multica_user }}"
  environment: "{{ _multica_user_env }}"
  when:
    - multica_autostart | bool
    - _multica_autostart_status.rc != 0
      or 'enabled' not in (_multica_autostart_status.stdout | default('') | lower)
  register: _multica_autostart_enable
  changed_when: true

# Lifecycle goes through systemd, never `multica daemon start|restart`. Those
# fork the daemon inside the CALLER's session (here, Ansible's SSH session
# scope), outside the unit's cgroup: the unit stays inactive, nothing
# supervises the process, and the next `systemctl --user start` collides with
# it on daemon.lock. Seen on haunted-mansion (2026-10-21) and spaceship-earth
# (2026-10-22).
#
# The unit name comes from `autostart status` ("Location: .../<name>.service")
# so a --profile host resolves its own unit.
- name: Daemon | Re-read the autostart registration
  ansible.builtin.command:
    argv: "{{ _multica_cmd + ['daemon', 'autostart', 'status'] }}"
  become: true
  become_user: "{{ multica_user }}"
  environment: "{{ _multica_user_env }}"
  register: _multica_autostart_reread
  changed_when: false
  failed_when: false
  check_mode: false
  when: _multica_autostart_enable is changed

- name: Daemon | Resolve the systemd user unit
  ansible.builtin.set_fact:
    _multica_unit: >-
      {{ ((_s.stdout | default('')) ~ '\n' ~ (_s.stderr | default('')))
         | regex_search('Location:\s*\S*/([^/\s]+\.service)', '\1')
         | default(['multica-daemon.service'], true) | first }}
  vars:
    _s: "{{ _multica_autostart_reread if _multica_autostart_enable is changed else _multica_autostart_status }}"

# `autostart enable` may rewrite the unit file while the user manager still
# holds the old definition.
- name: Daemon | Reload the user manager after a (re)registration
  ansible.builtin.command:
    argv: [systemctl, --user, daemon-reload]
  become: true
  become_user: "{{ multica_user }}"
  environment: "{{ _multica_user_env }}"
  when: _multica_autostart_enable is changed
  changed_when: true

- name: Daemon | Read the unit state
  ansible.builtin.command:
    argv: [systemctl, --user, is-active, "{{ _multica_unit }}"]
  become: true
  become_user: "{{ multica_user }}"
  environment: "{{ _multica_user_env }}"
  register: _multica_unit_state
  changed_when: false
  failed_when: false
  check_mode: false

- name: Daemon | Read daemon status
  ansible.builtin.command:
    argv: "{{ _multica_cmd + ['daemon', 'status', '--output', 'json'] }}"
  become: true
  become_user: "{{ multica_user }}"
  environment: "{{ _multica_user_env }}"
  register: _multica_daemon_status
  changed_when: false
  failed_when: false
  check_mode: false

# Running, but not under the unit: an orphan. Stop it so the unit can own the
# lock and the process.
- name: Daemon | Stop a daemon running outside its unit
  ansible.builtin.command:
    argv: "{{ _multica_cmd + ['daemon', 'stop'] }}"
  become: true
  become_user: "{{ multica_user }}"
  environment: "{{ _multica_user_env }}"
  when:
    - (_multica_unit_state.stdout | trim) != 'active'
    - _multica_daemon_status.rc == 0
    - ((_multica_daemon_status.stdout | from_json).status | default('')) == 'running'
  changed_when: true

- name: Daemon | Start the unit if it is not active
  ansible.builtin.command:
    argv: [systemctl, --user, start, "{{ _multica_unit }}"]
  become: true
  become_user: "{{ multica_user }}"
  environment: "{{ _multica_user_env }}"
  when: (_multica_unit_state.stdout | trim) != 'active'
  changed_when: true

# Anything that changed the binary, the config or the credentials restarts the
# daemon here, before verification reads its state back.
- name: Daemon | Flush handlers
  ansible.builtin.meta: flush_handlers