# ------------------------------------------------------------------------------
# FILE: roles/deploy-vllm/tasks/systemd.yml
# PHASE 4: vLLM systemd service(s).
#
# vLLM 0.5.x serves ONE model per process. The primary model (role: primary,
# e.g. Qwen2.5-32B-Instruct-AWQ) gets the canonical unit name vllm.service
# (matches the spec's /etc/systemd/system/vllm.service). Any additional
# enabled models (aux/embedding, added in later phases per the "Phased
# Strategy") each get their own instance unit vllm-<id>.service on a distinct
# port, generated from the same template.
#
# Idempotent: ansible.builtin.template only reports changed when content
# actually differs; the "restart vllm services" handler only fires on that
# change (or on api-key.yml rewriting the shared env file).
#
# vllm_service_state defaults to "stopped" — this role stages everything
# (venv, model, unit file, key) but does NOT flip production traffic without
# an explicit --extra-vars vllm_service_state=started, matching the deploy-
# then-validate-then-cutover sequencing approved for astro-orbiter.
# ------------------------------------------------------------------------------

- name: Render systemd unit for each enabled model
  ansible.builtin.template:
    src: vllm.service.j2
    dest: "/etc/systemd/system/{{ 'vllm.service' if item.role == 'primary' else 'vllm-' + item.id + '.service' }}"
    owner: root
    group: root
    mode: "0644"
  loop: "{{ vllm_enabled_models }}"
  loop_control:
    label: "{{ item.id }}"
  become: true
  notify: reload systemd

- name: Render workspace helper script (manual debugging / smoke-testing)
  ansible.builtin.template:
    src: vllm-workspace.sh.j2
    dest: "/home/{{ vllm_venv_owner }}/vllm-workspace.sh"
    owner: "{{ vllm_venv_owner }}"
    group: "{{ vllm_venv_owner }}"
    mode: "0750"
  become: true

- name: Flush handlers so unit files are known to systemd before enabling
  ansible.builtin.meta: flush_handlers

- name: Enable/disable + start/stop each vLLM systemd unit
  ansible.builtin.systemd:
    name: "{{ 'vllm.service' if item.role == 'primary' else 'vllm-' + item.id + '.service' }}"
    enabled: "{{ vllm_service_enabled }}"
    state: "{{ vllm_service_state }}"
    daemon_reload: true
  loop: "{{ vllm_enabled_models }}"
  loop_control:
    label: "{{ item.id }}"
  become: true