# pg_auto_failover data node — joins the monitor and lets the
# formation decide primary/secondary by election order. The first
# node to register becomes primary; later nodes become secondaries.
#
# Sync replication is configured by the monitor itself based on
# `number_sync_standbys` + `replication_quorum`, set on the formation
# in monitor.yml's post-init step.
---
- name: Check whether the data node is already initialised
  ansible.builtin.stat:
    path: "{{ pg_auto_failover_state_dir }}/postgres/postgresql.conf"
  register: node_initialised

- name: Initialise pg_auto_failover data node (joins the monitor)
  become: true
  become_user: postgres
  ansible.builtin.command:
    cmd: >
      /usr/lib/postgresql/{{ postgres_version }}/bin/pg_autoctl create postgres
      --pgdata {{ pg_auto_failover_state_dir }}/postgres
      --pgctl /usr/lib/postgresql/{{ postgres_version }}/bin/pg_ctl
      --pgport {{ pg_auto_failover_node_port }}
      --hostname {{ ansible_fqdn }}
      --monitor postgres://autoctl_node@{{ pg_auto_failover_monitor_host }}:{{ pg_auto_failover_monitor_port }}/{{ pg_auto_failover_monitor_dbname }}?sslmode=require
      --auth trust
      --ssl-self-signed
      --dbname {{ pg_auto_failover_app_dbname }}
      --username {{ pg_auto_failover_app_user }}
      --run-as-keeper
  args:
    creates: "{{ pg_auto_failover_state_dir }}/postgres/postgresql.conf"
  when: not node_initialised.stat.exists

- name: Render systemd unit for pg_autoctl data node
  ansible.builtin.template:
    src: pg_autoctl-node.service.j2
    dest: /etc/systemd/system/pg_autoctl.service
    owner: root
    group: root
    mode: "0644"
  notify: Restart pg_autoctl

- name: Enable + start pg_autoctl data node service
  ansible.builtin.systemd:
    name: pg_autoctl
    state: started
    enabled: true
    daemon_reload: true

- name: Set formation sync replication policy (run from any data node, idempotent)
  become: true
  become_user: postgres
  ansible.builtin.command:
    cmd: >
      /usr/lib/postgresql/{{ postgres_version }}/bin/pg_autoctl set formation
      number-sync-standbys {{ pg_auto_failover_number_sync_standbys }}
      --pgdata {{ pg_auto_failover_state_dir }}/postgres
  changed_when: false
  failed_when: false
  # Only one node needs to push the policy — but the command is
  # idempotent on the monitor side, so running it from every node
  # keeps the role re-entrant without coordination.
  run_once: false