config_pgcluster.yml

---
- name: config_pgcluster.yml | Configuration PostgreSQL HA Cluster (based on "Patroni" and "{{ dcs_type }}")
  hosts: all
  gather_facts: true
  vars_files:
    - vars/main.yml
    - vars/system.yml
  pre_tasks:
    - name: Include OS-specific variables
      ansible.builtin.include_vars: "vars/{{ ansible_os_family }}.yml"
      tags: always

    - name: Set maintenance variable
      ansible.builtin.set_fact:
        postgresql_cluster_maintenance: true
      tags: always

  roles:
    - role: pre-checks
      vars:
        minimal_ansible_version: 2.11.0
        timescale_minimal_pg_version: 12 # if enable_timescale is defined
      tags: always

    - role: hostname
    - role: resolv_conf
    - role: etc_hosts
    - role: timezone

- name: config_pgcluster.yml | Configure Postgres Cluster
  hosts: postgres_cluster
  become: true
  become_method: sudo
  gather_facts: true
  any_errors_fatal: true
  vars_files:
    - vars/main.yml
    - vars/system.yml

  pre_tasks:
    - name: Include OS-specific variables
      ansible.builtin.include_vars: "vars/{{ ansible_os_family }}.yml"
      tags: always

    - name: Checking Linux distribution
      ansible.builtin.fail:
        msg: "{{ ansible_distribution }} is not supported"
      when: ansible_distribution not in os_valid_distributions

    - name: Checking version of OS Linux
      ansible.builtin.fail:
        msg: "{{ ansible_distribution_version }} of {{ ansible_distribution }} is not supported"
      when: ansible_distribution_version is version_compare(os_minimum_versions[ansible_distribution], '<')

    - name: Update apt cache
      ansible.builtin.apt:
        update_cache: true
        cache_valid_time: 3600
      register: apt_status
      until: apt_status is success
      delay: 5
      retries: 3
      environment: "{{ proxy_env | default({}) }}"
      when: ansible_os_family == "Debian" and installation_method == "repo"
      tags: add_repo, install_packages, install_postgres

    - name: Make sure the gnupg and apt-transport-https packages are present
      ansible.builtin.apt:
        pkg:
          - gnupg
          - apt-transport-https
        state: present
      register: apt_status
      until: apt_status is success
      delay: 5
      retries: 3
      environment: "{{ proxy_env | default({}) }}"
      when: ansible_os_family == "Debian" and installation_method == "repo"
      tags: add_repo, install_packages, install_postgres

    - name: Build a firewall_ports_dynamic_var
      ansible.builtin.set_fact:
        firewall_ports_dynamic_var: "{{ firewall_ports_dynamic_var | default([]) + (firewall_allowed_tcp_ports_for[item] | default([])) }}"
      loop: "{{ hostvars[inventory_hostname].group_names }}"
      when: firewall_enabled_at_boot | bool
      tags: config_firewall, firewall

    - name: Build a firewall_rules_dynamic_var
      ansible.builtin.set_fact:
        firewall_rules_dynamic_var: "{{ firewall_rules_dynamic_var | default([]) + (firewall_additional_rules_for[item] | default([])) }}"
      loop: "{{ hostvars[inventory_hostname].group_names }}"
      when: firewall_enabled_at_boot | bool
      tags: firewall

  roles:
    - role: ansible-role-firewall
      environment: "{{ proxy_env | default({}) }}"
      vars:
        firewall_allowed_tcp_ports: "{{ firewall_ports_dynamic_var | default([]) | unique }}"
        firewall_additional_rules: "{{ firewall_rules_dynamic_var | default([]) | unique }}"
      when: firewall_enabled_at_boot|bool
      tags: firewall

    - role: add-repository
    - role: packages
    - role: sudo
    - role: swap
    - role: sysctl
    - role: transparent_huge_pages
    - role: pam_limits
    - role: io-scheduler
    - role: locales
    - role: ntp
    - role: ssh-keys
    - role: copy

- name: config_pgcluster.yml | Configure HAProxy Load Balancing
  ansible.builtin.import_playbook: balancers.yml
  when: with_haproxy_load_balancing|bool
  tags: config_balancers,load_balancing, haproxy

- name: config_pgcluster.yml | Configure Postgres Cluster
  hosts: postgres_cluster
  become: true
  become_method: sudo
  gather_facts: true
  any_errors_fatal: true
  handlers:
    - ansible.builtin.import_tasks: roles/patroni/handlers/main.yml
    - ansible.builtin.import_tasks: roles/pgbouncer/handlers/main.yml
  vars_files:
    - vars/main.yml
    - vars/system.yml

  pre_tasks:
    - name: Include OS-specific variables
      ansible.builtin.include_vars: "vars/{{ ansible_os_family }}.yml"
      tags: always

  roles:
    - role: pgpass

    - role: cron

    - role: patroni/config

    - role: vip-manager
      when: not with_haproxy_load_balancing|bool and
        (cluster_vip is defined and cluster_vip | length > 0)

    # optional
    - role: postgresql-users
      when: is_master | bool and postgresql_users | length > 0

    - role: postgresql-databases
      when: is_master | bool and postgresql_databases | length > 0

    - role: postgresql-schemas
      when: is_master | bool and postgresql_schemas | length > 0

    - role: postgresql-extensions
      when: is_master | bool and postgresql_extensions | length > 0

    - role: pgbouncer/config
      when: pgbouncer_install|bool

- name: config_pgcluster.yml | Check needed restart cluster and prepare for it
  hosts: postgres_cluster
  gather_facts: true
  become: true
  become_method: sudo
  any_errors_fatal: true
  vars_files:
    - vars/main.yml
  tasks:
    - name: "[Prepare] Get Patroni Cluster Leader Node"
      ansible.builtin.uri:
        url: http://{{ inventory_hostname }}:{{ patroni_restapi_port }}/leader
        status_code: 200
      register: patroni_leader_result
      changed_when: false
      failed_when: false

    - name: '[Prepare] Add host to group "primary" (in-memory inventory)'
      ansible.builtin.add_host:
        name: "{{ item }}"
        groups: primary
      when: hostvars[item]['patroni_leader_result']['status'] == 200
      loop: "{{ groups['postgres_cluster'] }}"
      changed_when: false

    - name: '[Prepare] Add hosts to group "secondary" (in-memory inventory)'
      ansible.builtin.add_host:
        name: "{{ item }}"
        groups: secondary
      when: hostvars[item]['patroni_leader_result']['status'] != 200
      loop: "{{ groups['postgres_cluster'] }}"
      changed_when: false

    - name: "Print Patroni Cluster info"
      ansible.builtin.debug:
        msg:
          - "Cluster Name: {{ patroni_cluster_name }}"
          - "Cluster Leader: {{ ansible_hostname }}"
      when: inventory_hostname in groups['primary']

    - name: "Check if there are any changed parameters that require a restart"
      become_user: postgres
      community.postgresql.postgresql_query:
        login_host: "127.0.0.1"
        login_port: "{{ postgresql_port }}"
        login_user: "{{ patroni_superuser_username }}"
        login_password: "{{ patroni_superuser_password }}"
        login_db: "postgres"
        query: "select name from pg_settings where pending_restart is true"
      register: pending_restart_result

    - name: "Set pg_pending_restart_settings variable"
      ansible.builtin.set_fact:
        pg_pending_restart_settings: "{{ pending_restart_result.query_result }}"

    - name: "Display parameters requiring PostgreSQL restart"
      ansible.builtin.debug:
        msg:
          - "On server {{ ansible_hostname }}, the following parameters have changed and require PostgreSQL to restart:"
          - "{{ pg_pending_restart_settings | map(attribute='name') | list }}"
      when: pg_pending_restart_settings | length > 0
  tags:
    - patroni_conf

- name: config_pgcluster.yml | Restart patroni on secondary after config settings if need
  hosts: secondary
  serial: 1 # restart replicas one by one
  gather_facts: false
  become: true
  become_method: sudo
  any_errors_fatal: true
  vars_files:
    - vars/main.yml
  pre_tasks:
    - name: Include OS-specific variables
      ansible.builtin.include_vars: "vars/{{ ansible_os_family }}.yml"
      tags: always

  tasks:
    - name: Stop read-only traffic
      ansible.builtin.include_role:
        name: update
        tasks_from: stop_traffic
      when:
        - pending_restart | bool
        - pg_pending_restart_settings | length > 0

    - name: Stop Services
      ansible.builtin.include_role:
        name: update
        tasks_from: stop_services
      when:
        - pending_restart | bool
        - pg_pending_restart_settings | length > 0

    - name: Start Services
      ansible.builtin.include_role:
        name: update
        tasks_from: start_services
      when:
        - pending_restart | bool
        - pg_pending_restart_settings | length > 0

    - name: Start read-only traffic
      ansible.builtin.include_role:
        name: update
        tasks_from: start_traffic
      when:
        - pending_restart | bool
        - pg_pending_restart_settings | length > 0
  tags:
    - patroni_conf

- name: config_pgcluster.yml | Restart patroni on master after config settings if need
  hosts: primary
  gather_facts: false
  become: true
  become_method: sudo
  any_errors_fatal: true
  environment: "{{ proxy_env | default({}) }}"
  vars_files:
    - vars/main.yml
  pre_tasks:
    - name: Include OS-specific variables
      ansible.builtin.include_vars: "vars/{{ ansible_os_family }}.yml"
      tags: always

  tasks:
    - name: Switchover Patroni leader role
      ansible.builtin.include_role:
        name: update
        tasks_from: switchover
      when:
        - pending_restart | bool
        - pg_pending_restart_settings | length > 0

    - name: Stop read-only traffic
      ansible.builtin.include_role:
        name: update
        tasks_from: stop_traffic
      when:
        - pending_restart | bool
        - pg_pending_restart_settings | length > 0

    - name: Stop Services
      ansible.builtin.include_role:
        name: update
        tasks_from: stop_services
      when:
        - pending_restart | bool
        - pg_pending_restart_settings | length > 0

    - name: Start Services
      ansible.builtin.include_role:
        name: update
        tasks_from: start_services
      when:
        - pending_restart | bool
        - pg_pending_restart_settings | length > 0

    - name: Start read-only traffic
      ansible.builtin.include_role:
        name: update
        tasks_from: start_traffic
      when:
        - pending_restart | bool
        - pg_pending_restart_settings | length > 0
  tags:
    - patroni_conf