use conditionals in vars ansible

Question

Can we use conditionals in "vars:" section of a playbook, I am aware of set_fact in tasks ,but I want to know we could use in section like below:

---
- hosts: "{{ host1 }}"
  vars:
   var1: "{{ passed_var1 }}"
   var2: "<conditionally assign value based on {{ var1 }}"

Answer 1

You can do something like:

---
- name: Test Play
  hosts: local
  gather_facts: false

  vars: 
    var1: hola
    var2: "{{ 'foo' if var1 else '' }}"

  tasks:
    - name: debug var1
      debug:
        var: var1

    - name: debug var2
      debug:
        var: var2

You will get:

PLAY [Test Play] ***************************************************************

TASK [debug1] ******************************************************************
ok: [localhost] => {
    "var1": "hola"
}

TASK [debug1] ******************************************************************
ok: [localhost] => {
    "var2": "foo"
}

Another Example:

---
- name: Test Play
  hosts: local
  gather_facts: false

  vars: 
    var1: hola
    var2: "{{ 'foo' if var1 == 'hola' else '' }}"

  tasks:
    - name: debug var1
      debug:
        var: var1

    - name: debug var2
      debug:
        var: var2