ansible/test/playbook-when.yml

---
- hosts: all
  connection: local
  gather_facts: False

  vars: 
    internal: "print me"

  tasks: 
  - action: debug msg="skip me"
    when_unset: $internal

  - action: debug msg="$internal"
    when_set: $internal

  - action: debug msg="skip me"
    when_unset: $external

  - action: debug msg="$external"
    when_set: $external

  - action: debug msg="run me"
    when_unset: $this_var_does_not_exist

  - action: debug msg="skip me"
    when_set: $this_var_does_not_exist
Prevent premature substitution of variables into tasks As documented in #2623, early variable substitution causes when_ tests to fail and possibly other side effects. I can see the reason for this early substitution, likely introduced in 1dfe60a6, to allow many playbook parameters to be templated. This is a valid goal, but the recursive nature of the utils.template function means that it goes too far. At this point removing tasks from the list of parameters to be substituted seems sufficient to make my tests pass. It may be the case that other parameters should be excluded, but I suspect not. Adding a test case. I would prefer to analyse not just the aggregate statistics but also whether the results are as expected - I can't see an easy way to do that with the available callbacks at present. 12 years ago			`---`
			`- hosts: all`
			`connection: local`
			`gather_facts: False`

			`vars:`
			`internal: "print me"`

			`tasks:`
			`- action: debug msg="skip me"`
			`when_unset: $internal`

			`- action: debug msg="$internal"`
			`when_set: $internal`

			`- action: debug msg="skip me"`
			`when_unset: $external`

			`- action: debug msg="$external"`
			`when_set: $external`

			`- action: debug msg="run me"`
			`when_unset: $this_var_does_not_exist`

			`- action: debug msg="skip me"`
			`when_set: $this_var_does_not_exist`