Registering variables from a looped task and conditionals for skipped tasks

Question

I'm trying to figure out a port test task in a playbook. I have two different sets of ports that need to be checked, but only checked if the server hostname has dev/test/stg/eng in it. Then everything else will be considered a production host and the production ports will be checked.

Here is my playbook:

- name: Filebeat Firewall port check | Dev
  wait_for:
    host: "{{ item.name }}"
    port: "{{ item.port }}"
    state: started
    delay: 0
    timeout: 5
  loop: "{{ dev_ports }}"
  register: devresults
  when: ansible_facts['hostname'] | regex_search('dev|tst|test|eng')

- name: Filebeat Firewall port check | Prod
  wait_for:
    host: "{{ item.name }}"
    port: "{{ item.port }}"
    state: started
    delay: 0
    timeout: 5
  loop: "{{ prod_ports }}"
  when: devresults is skipped

The first task runs as expected when ran against a production server (is skipped) and a development server (ports are checked). However, the second task is skipped when ran against a production server, as well as a development server (this should happen).

Basically, if the first task is skipped the second task should run, and if the first ran the second task should be skipped, this isn't happening. I'm not sure what I'm missing, I'm thinking its the when statement in the second task, or if the loop is causing my issue, any help would be welcomed.

Answer 1

Regarding your question

Basically, if the first task is skipped the second task should run, and if the first ran the second task should be skipped, this isn't happening.

I've setup a short first example

---
- hosts: localhost
  become: false
  gather_facts: false

  tasks:

  - name: Create result set
    shell:
      cmd: echo 'I am not skipped.'
    register: result
    when: not ansible_check_mode

  - name: Show result when not skipped
    debug:
      var: result
    when: not result.skipped | default('false') | bool

  - name: Show result when skipped
    debug:
      var: result
    when: result.skipped | default('false') | bool

and found it working when running with ansible-playbook skip.yml and ansible-playbook skip.yml --check.

Depending on the task and used modules, the reason seems to be when a task becomes skipped the result set is

TASK [Show result when skipped] **************************
ok: [localhost] =>
  result:
    changed: false
    skip_reason: Conditional result was False
    skipped: true

whereby when not skipped the result set is

TASK [Show result when not skipped] *********************
ok: [localhost] =>
  result:
    changed: true
    cmd: echo 'I am not skipped.'
    delta: '0:00:00.123456'
    end: '2022-02-16 20:00:00.123456'
    failed: false
    rc: 0
    start: '2022-02-16 20:00:00.000000'
    stderr: ''
    stderr_lines: []
    stdout: I am not skipped.
    stdout_lines:
    - I am not skipped.

and don't has the skipped flag. Therefore you may introduce filter to Provide default values and to Force the data type.

---

Regarding your objection

"the example doesn't really applies as it isn't doing any loops"

you may have a look into the result set of the following second example with loop and Extended loop variables.

---
- hosts: localhost
  become: false
  gather_facts: false

  tasks:

  - name: Create result set
    shell:
      cmd: echo 'I am not skipped.'
    register: result
    when: item is even
    loop: "{{ [1,2] }}"
    loop_control:
      extended: true
      label: "{{ item }}"

  - name: Show result
    debug:
      var: result

which produce an output of

TASK [Create result set] *******
changed: [localhost] => (item=2)

TASK [Show result] ******************************
ok: [localhost] =>
  result:
    changed: true
    msg: All items completed
    results:
    - ansible_loop:
        allitems:
        - 1
        - 2
        first: true
        index: 1
        index0: 0
        last: false
        length: 2
        nextitem: 2
        revindex: 2
        revindex0: 1
      ansible_loop_var: item
      changed: false
      item: 1
      skip_reason: Conditional result was False
      skipped: true
    - ansible_loop:
        allitems:
        - 1
        - 2
        first: false
        index: 2
        index0: 1
        last: true
        length: 2
        previtem: 1
        revindex: 1
        revindex0: 0
      ansible_loop_var: item
      changed: true
      cmd: echo 'I am not skipped.'
      delta: '0:00:00.123456'
      end: '2022-02-16 22:15:00.123456'
      failed: false
      invocation:
        module_args:
          _raw_params: echo 'I am not skipped.'
          _uses_shell: true
          argv: null
          chdir: null
          creates: null
          executable: null
          removes: null
          stdin: null
          stdin_add_newline: true
          strip_empty_ends: true
          warn: true
      item: 2
      rc: 0
      start: '2022-02-16 22:15:00.000000'
      stderr: ''
      stderr_lines: []
      stdout: I am not skipped.
      stdout_lines:
      - I am not skipped.

As you can see it is a data structure containing a list of items and it does contain the information about the first skipped item. To access it you may enhance the second example with

  - name: Show result when skipped
    debug:
      msg: "{{ item.item }}"
    when: item.skipped | default('false') | bool
    loop: "{{ result.results }}"
    loop_control:
      extended: true
      label: "{{ item }}"

and have a look into the output. It also works according the examples of Conditions based on registered variables.

  - name: Show result when skipped
    debug:
      msg: "{{ item.item }}"
    when: item is skipped
    loop: "{{ result.results }}"

Further Reading

• Troubleshoot Ansible Playbooks
• Ansible - Check variable type
• Discovering the data type