How to print a warning from a task

Sometime there is a strong desire to print some visible warning on screen in the middle of a playbook, playbook with megabytes of output.

Unfortunately, there is no warning module in Ansible. Fortunately, we can construct something as eye-catchy as warning should be.

Consider this:

- hosts: localhost
  gather_facts: no
  connection: local
  tasks:
  - name: Check if such things are allowed
    fail:
      msg: '{{item}} is attempted but {{item}} is not in allowed list'
    ignore_errors: yes
    with_items: '{{ things_to_do }}'
    when: item not in allowed_things
  vars:
   allowed_things:
    - be_happy
   things_to_do:
    - swear
    - be_happy
    - annoy_people

It will produce this output. I resorted to ‘png-output’ as colors are important.

As you can see, there is a red color and a ‘failed’ label from fail module is strong enough to draw users attention, but ignore_errors is grace enough to allow the play to continue to work (that’s what we want from ‘warning’, aren’t we?)

Conclusion

Odd combination of fail, when and ignore_errors allows to create an imitation of warning in Ansible.