---
- name: 📊 Gather service facts
  ansible.builtin.service_facts:

- name: ✅ Assert systemd is available
  ansible.builtin.assert:
    that:
      - ansible_facts['service_mgr'] == "systemd"
    fail_msg: >
      systemd is not available. This role requires systemd (service manager = {{ ansible_facts['service_mgr'] }}).

- name: 📖 Read PID 1 process name
  ansible.builtin.slurp:
    src: /proc/1/comm
  register: pid1_comm

- name: 🛑 Fail if PID1 is not systemd
  ansible.builtin.assert:
    that:
      - pid1_comm.content | b64decode | trim == "systemd"
    fail_msg: "PID 1 is not systemd (PID1={{ pid1_comm.content | b64decode | trim }}). Docker service management will hang."

- name: 🔎 Check docker socket
  ansible.builtin.stat:
    path: /var/run/docker.sock
  register: docker_sock

- name: ✅ Assert docker service exists
  ansible.builtin.assert:
    that:
      - "'docker.service' in ansible_facts.services"
    fail_msg: >
      docker.service is not registered in systemd.
      Docker engine does not appear to be installed.