---
# Tasks to validate swapfile management (enabling/disabling its use) on Linux.
# The swapfile COULD be associated to a loop device, that would become the 'src'.

- name: Swap off all (try to cleanup previous erraneous tests)
  command:
    cmd: swapoff -a


- name: Try to activate swapfile
  vars:
    swapfile: /var/swapfile0

  block:
    - name: Create a file to be used for memory swapping
      command:
        cmd: "dd if=/dev/zero of={{ swapfile }} bs=1M count=64"
        creates: "{{ swapfile }}"

    - name: Setup permissions suitable for swap usage
      file:
        path: "{{ swapfile }}"
        mode: u=rw,go=
        state: file

    - name: Create a swap filesystem into the dedicated file
      community.general.filesystem:
        dev: "{{ swapfile }}"
        fstype: swap


    - name: Get swap info (0)
      command: swapon --noheadings --show=name,prio
      register: swap_info_0
      changed_when: false

    - name: Assert that swap file {{ swapfile }} is not used by swap
      assert:
        that:
          - swap_info_0.stdout | length == 0


    - name: Enable swap file with priority 1234
      mount:
        path: none
        src: "{{ swapfile }}"
        fstype: swap
        opts: pri=1234
        state: mounted
      register: swap_enabled_1

    - name: Get swap info (1)
      command: swapon --noheadings --show=name,prio
      register: swap_info_1
      changed_when: false

    - name: Assert that swap file is enabled with priority 1234
      assert:
        that:
          - swap_enabled_1 is changed
          - swap_info_1.stdout_lines[0].split()[1] | int == 1234


    - name: Update swap priority to 10
      mount:
        path: none
        src: "{{ swapfile }}"
        fstype: swap
        opts: pri=10
        state: mounted
      register: swap_enabled_2

    - name: Get swap info (2)
      command: swapon --noheadings --show=name,prio
      register: swap_info_2
      changed_when: false

    - name: Assert that swap file is enabled with priority 10
      assert:
        that:
          - swap_enabled_2 is changed
          - swap_info_2.stdout_lines[0].split()[1] | int == 10


    - name: Update swap priority to 10, again
      mount:
        path: none
        src: "{{ swapfile }}"
        fstype: swap
        opts: pri=10
        state: mounted
      register: swap_enabled_3

    - name: Get swap info (3)
      command: swapon --noheadings --show=name,prio
      register: swap_info_3
      changed_when: false

    - name: Assert that nothing changed
      assert:
        that:
          - swap_enabled_3 is not changed
          - swap_info_3.stdout_lines == swap_info_2.stdout_lines

  always:
    - name: Disable swap file
      mount:
        path: none
        src: "{{ swapfile }}"
        fstype: swap
        state: absent
      register: swap_disabled_1

    - name: Get swap info (4)
      command: swapon --noheadings --show=name,prio
      register: swap_info_4
      changed_when: false

    - name: Assert that swap file is disabled
      assert:
        that:
          - swap_disabled_1 is changed
          - swap_info_4.stdout_lines == swap_info_0.stdout_lines


    - name: Disable swap file, again
      mount:
        path: none
        src: "{{ swapfile }}"
        fstype: swap
        state: absent
      register: swap_disabled_2

    - name: Get swap info (5)
      command: swapon --noheadings --show=name,prio
      register: swap_info_5
      changed_when: false

    - name: Assert that swap file is disabled and nothing changed
      assert:
        that:
          - swap_disabled_2 is not changed
          - swap_info_5.stdout_lines == swap_info_0.stdout_lines


    - name: Remove swap file
      file:
        path: "{{ swapfile }}"
        state: absent


- name: Swap on all (try to restore pre-test state)
  command:
    cmd: swapon -a