Add an item to a list dependent on a conditional in ansible

Question

I would like to add an item to a list in ansible dependent on some condition being met.

This doesn\'t work:

  some_dictionary:
    app:
       - some         


        

Answer 1

You can filter out all falsey values with select(), but remember to apply the list() filter afterwards. This seems an easier and more readable approach for me:

- name: Test
  hosts: localhost
  gather_facts: no
  vars:
      mylist:
        - "{{ (true)  | ternary('a','') }}"
        - "{{ (false) | ternary('b','') }}"
        - "{{ (true)  | ternary('c','') }}"
 
  tasks:
  - debug:
      var: mylist|select|list

Result:

TASK [debug] *****************************************************************************************************************************************************************************************************************
ok: [localhost] => {
    "mylist|select()|list": [
        "a", 
        "c"
    ]
}

Replace (true) and (false) with whatever test you want.