postgresql-replicated.yml

# A replicated postgres cluster installer that works on single node too
---
- hosts: all
  sudo: yes
  remote_user: root

  vars:
    main_nodes_ips: "{% set IP_ARR=[] %}{% for host in groups['all'] %}{% if IP_ARR.insert(loop.index,hostvars[host]['ansible_default_ipv4']['address']) %}{% endif %}{% endfor %}{{IP_ARR|join(' ')}}"
    main_nodes_ipc: "{% set IP_ARR=[] %}{% for host in groups['all'] %}{% if IP_ARR.insert(loop.index,hostvars[host]['ansible_default_ipv4']['address']) %}{% endif %}{% endfor %}{{IP_ARR|join(',')}}"
    master_name: "{{ hostvars[groups['all'][0]]['ansible_hostname'] }}"
    master_ip: "{{ hostvars[groups['all'][0]]['ansible_default_ipv4'] }}"
    slave_name: "{{ hostvars[groups['all'][1]]['ansible_hostname'] }}"
    slave_ip: "{{ hostvars[groups['all'][1]]['ansible_default_ipv4'] }}"
    host_count: "{{ groups['all'] | length }}"
    service_name: postgresql

  vars_files:
    - "{{ var_file }}"

  tasks:

  ####
  # Start task: basics
  # Add packages & stop service for now
  - name: Postgresql ensure packages installed
    apt: pkg={{ item }} state=latest
    with_items:
      - "postgresql-9.6"
      - "postgresql-client-9.6"
      
  # Get information about user
  - name: Postgresql replication user info
    sudo: yes
    sudo_user: postgres
    command: psql -c "SELECT 999 FROM pg_roles WHERE rolname='repuser'"
    register: repuser

  # Create replication user 
  - name: Postgresql create replication user 
    sudo: yes
    sudo_user: postgres
    command: "psql -c \"CREATE ROLE repuser PASSWORD '{{ postgres.replication.user }}' REPLICATION LOGIN; \""
    when: "{{ repuser.stdout.find('999') == -1 }}"
    
  # Stop service 
  - name: Postgresql Stop service
    command: service {{ service_name }} stop
      
  # Make sure all required directories are available
  - name: postgresql create infra dirs
    command: mkdir -p {{ item }} 
    with_items:
        - /infra/etc/{{ cluster_name }}/postgresql/9.6/main
        - /infra/etc/{{ cluster_name }}/network
        - /infra/etc/{{ cluster_name }}/network/iptables-specific.d
        - /etc/network/iptables-specific.d
        - /var/lib/postgresql/9.6/wals

  # Make sure all postgresql directories have right ownership
  - name: postgresql chown postgres dirs
    command: chown postgres:postgres /var/lib/postgresql/9.6/wals 
    with_items:
        - /var/lib/postgresql/9.6/wals

  # end task: basics
  ####

  ####
  # start task: postgresql service configuration
  - name: postgresql check for postgresql conf files info
    stat: path=/infra/etc/{{ cluster_name }}/postgresql/9.6/main/{{item.infra}}
    register: stat_result 
    with_items:
        - { dest: 'postgresql.conf', infra: "postgresql.master.conf.{{ ansible_hostname }}" , template: 'postgresql.master.conf'  }
        - { dest: 'postgresql.conf',  infra: "postgresql.slave.conf.{{ ansible_hostname }}" , template: 'postgresql.slave.conf'  }
        - { dest: 'pg_hba.conf', infra: 'pg_hba.conf', template: 'pg_hba.conf' }
        - { dest: 'pg_ident.conf', infra: 'pg_ident.conf', template: 'pg_ident.conf' }
        - { dest: 'start.conf', infra: 'start.conf', template: 'start.conf' }
        - { dest: 'pg_ctl.conf', infra: 'pg_ctl.conf', template: 'pg_ctl.conf' }
        - { dest: 'environment', infra: 'environment', template: 'environment' }
 
  # ensure the package conf is absent
  - name : remove package source conf 
    command : rm -f /etc/postgresql/9.6/main/{{item.item.dest}}
    when: not item.stat.exists
    with_items: "{{ stat_result.results }}"

  # templates
  - name: postgresql generate postgresql template conf files 
    template:
        force: yes 
        src: templates/postgresql/9.6/main/{{item.item.template}}
        dest: /infra/etc/{{ cluster_name }}/postgresql/9.6/main/{{item.item.infra}}
        owner: postgres
        group: postgres
        mode: 0660
    when: not item.stat.exists
    with_items: "{{ stat_result.results }}"

  # deploy conf on master
  - name: postgresql symlink master conf file
    command: ln -s  /infra/etc/{{ cluster_name }}/postgresql/9.6/main/{{item.item.infra}} /etc/postgresql/9.6/main/{{item.item.dest}}
    when: 
      - "'{{ ansible_hostname }}' == '{{ master_name }}'"
      - not item.stat.exists 
      - item.item.template != "postgresql.slave.conf"
    with_items: "{{ stat_result.results }}"

  # deploy conf on slave
  - name: postgresql symlink slave conf file
    command: ln -s  /infra/etc/{{ cluster_name }}/postgresql/9.6/main/{{item.item.infra}} /etc/postgresql/9.6/main/{{item.item.dest}}
    when: 
      - "'{{ ansible_hostname }}' != '{{ master_name }}'"
      - not item.stat.exists 
      - item.item.template != "postgresql.master.conf"
    with_items: "{{ stat_result.results }}"
  
  # end task: postgresql service configuration
  ####

  ####
  # start task: postgresql recovery configuration
  - name: postgresql check for postgresql recovery file info
    stat: path=/infra/etc/{{ cluster_name }}/postgresql/9.6/main/{{item.infra}}
    register: stat_result 
    with_items:
        - { dest: 'recovery.conf',  infra: "recovery.conf.{{ ansible_hostname }}" }
    when: 
      - "{{ host_count == 2 }}"
 
  # master template
  - name: postgresql generate master postgresql template recovery files 
    template:
        force: yes 
        src: templates/postgresql/9.6/main/recovery.master.conf
        dest: /infra/etc/{{ cluster_name }}/postgresql/9.6/main/{{item.item.infra}}
        owner: root 
        group: root
        mode: 0600
    when: 
      - "{{ host_count == 2 }}"
      - "'{{ ansible_hostname }}' == '{{ master_name }}'"
      - not item.stat.exists 
    with_items: "{{ stat_result.results }}"
 
  # slave template
  - name: postgresql generate slave  postgresql template recovery files 
    template:
        force: yes 
        src: templates/postgresql/9.6/main/recovery.slave.conf
        dest: /infra/etc/{{ cluster_name }}/postgresql/9.6/main/{{item.item.infra}}
        owner: root 
        group: root
        mode: 0600
    when: 
      - "{{ host_count == 2 }}"
      - "'{{ ansible_hostname }}' != '{{ master_name }}'"
      - not item.stat.exists 
    with_items: "{{ stat_result.results }}"
 
  # deploy recovery  on slave
  - name: postgresql symlink slave recovery file
    command: cp /infra/etc/{{ cluster_name }}/postgresql/9.6/main/{{item.item.infra}} /var/lib/postgresql/9.6/main/{{item.item.dest}}
    when: 
      - "{{ host_count == 2 }}"
      - "'{{ ansible_hostname }}' != '{{ master_name }}'"
      - not item.stat.exists 
    with_items: "{{ stat_result.results }}"
  
  # end task: postgresql recovery configuration 
  ####
      
  ####
  # start task: iptables configuration
  - name: postgresql check for iptables files info
    stat: path={{item.src}}
    register: stat_result
    with_items:
        - { name: 'iptables_specific', tmpl: 'files/iptables-specific',src: '/infra/etc/{{ cluster_name }}/network/iptables-specific', dest: '/etc/network/iptables-specific' }
        - { name: 'iptables_postgresql', tmpl: 'templates/iptables.postgresql.conf',src: '/infra/etc/{{ cluster_name }}/network/iptables-specific.d/postgresql.conf', dest: '/etc/network/iptables-specific.d/postgresql.conf' }

  - name: postgresql create firewall file from template
    template:
        src: "{{ item.item.tmpl }}"
        dest: "{{ item.item.src }}"
        owner: root
        group: root 
        mode: 0755
    when: not item.stat.exists
    with_items: "{{ stat_result.results }}"
        
  - name: Postgresql symlink iptables-specific files
    command: ln -s {{ item.item.src }} {{ item.item.dest }} 
    when: not item.stat.exists
    with_items: "{{ stat_result.results }}"
   
  - name: Postgresql Reload Firewall
    command: /etc/network/iptables_on.sh
  # End task: Iptables configuration
  ####
       
  ####
  # Restart service
  - name: Postgresql Start services
    command: service {{ service_name }} start