CODEWITHSUNDEEP
ansibleconditional-statements
MountainX
MountainX

Reputation: 6337

Warning: Ansible evaluating bare variable. How do I implement this correctly?

My Ansible conditional statements are not evaluating correctly.

- name: A
  shell:
    cmd: /usr/local/bin/is_A_OK #returns bash true or false (not strings)
  register: is_A_OK

- name: B
  shell:
    cmd: /usr/local/bin/is_B_OK 
  register: is_B_OK

- name: reboot if both are OK
  reboot:
  when:
    - is_A_OK
    - is_B_OK

[DEPRECATION WARNING]: evaluating 'is_A_ok' as a bare variable, this behaviour will go away and you might need to add |bool to the expression in the future. Also see CONDITIONAL_BARE_VARS configuration toggle. This feature will be removed in version 2.12.

However, the logic works correctly, and the reboot is performed when both variables are true. But I can't leave it as-is given that this feature will be removed in version 2.12.

FYI, the bash scripts conclude like this:

if [[ "$my_var" == true ]]; then
    true
else
    false
fi

I'm running Arch Linux, so bash is new.

The warning plus the ansible docs made me think this would be correct:

- name: reboot if OK
  reboot:
  when:
    - is_A_OK|bool
    - is_B_OK|bool

The warning goes away, but the reboot is not preformed, even when both variables are true. I guess I don't understand the docs. (I'm new to Ansible.)

I found this question, but it is not relevant: Ansible conditional statements not evaluating correctly - Stack Overflow Ansible conditional statements not evaluating correctly

What am I doing wrong and not understanding?

Upvotes: 2

Views: 4393

Answers (1)

Vladimir Botka
Vladimir Botka

Reputation: 68034

Short answer: Either test the attribute rc of the registered dictionary or use task results to test success.

Details: The return code of the command is stored in the attribute rc of the registered dictionary. The command

    - command: /bin/true
      register: result_A
    - debug:
        var: result_A.rc
    - debug:
        msg: "{{ (result_A is success)|ternary('OK', 'KO') }}"
    - debug:
        msg: "{{ result_A|ternary('OK', 'KO') }}"

returns rc=0 as a result of /bin/true. Use task results to test success. Testing of bare variable result_A gives True because the variable is not empty. It also produces the deprecation warning.

    "result_A.rc": "0"
    "msg": "OK"
    "msg": "OK"

In the case of /bin/false the command

    - command: /bin/false
      register: result_B
      ignore_errors: true
    - debug:
        var: result_B.rc
    - debug:
        msg: "{{ (result_B is success)|ternary('OK', 'KO') }}"
    - debug:
        msg: "{{ result_B|ternary('OK', 'KO') }}"

returns rc=1 and the task would fail without ignore_errors: true.

fatal: [localhost]: FAILED! => {"changed": true, "cmd": ["/bin/false"], "delta": "0:00:00.003322", "end": "2020-06-14 07:07:17.620345", "msg": "non-zero return code", "rc": 1, "start": "2020-06-14 07:07:17.617023", "stderr": "", "stderr_lines": [], "stdout": "", "stdout_lines": []} ...ignoring

The test success fails and testing of result_B gives True because the variable is not empty.


    "result_B.rc": "1"
    "msg": "KO"
    "msg": "OK"

Upvotes: 6

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