Ansible: When Variable Is – Defined | Exists | Empty | True

Ansible ‘When’ Statement: Check If Variable Is…

Check if Ansible variable is defined (exists):

tasks:

- shell: echo "The variable 'foo' is defined: '{{ foo }}'"
  when: foo is defined

- fail: msg="The variable 'bar' is not defined"
  when: bar is undefined

Check if Ansible variable is empty:

tasks:
- fail: msg="The variable 'bar' is empty"
  when: bar|length == 0

- shell: echo "The variable 'foo' is not empty: '{{ foo }}'"
  when: foo|length > 0

Check if Ansible variable is defined and not empty:

tasks:

- shell: echo "The variable 'foo' is defined and not empty"
  when: (foo is defined) and (foo|length > 0)

- fail: msg="The variable 'bar' is not defined or empty"
  when: (bar is not defined) or (bar|length == 0)

Check if Ansible variable is True or False:

tasks:

- shell: echo "The variable 'foo' is 'True'"
  when: foo|bool == True

- shell: echo "The variable 'bar' is 'False'"
  when: bar|bool == False

https://www.shellhacks.com/ansible-when-variable-is-defined-exists-empty-true/

 

Ansible: When Variable Is - Defined | Exists | Empty | True - ShellHacks