vpn-test.yml

---
- name: set parameters for test
  hosts: localhost
  tasks:
    - set_fact:
        vpn_connections:
          - type: psk
            hosts:
              hosta:
              hostb:

    - name: show connections
      debug:
        msg: conns {{ vpn_connections | to_nice_json }}

    - name: add psk to each tunnel
      set_fact:
        vpn_connections: |
          {% for tunnel in vpn_connections | selectattr("type", "equalto", "psk") %}
          {%   if "psk" not in tunnel %}
          {%     set _ = tunnel.__setitem__("psk", "need to create psk") %}
          {%   endif %}
          {% endfor %}
          {{ vpn_connections }}

    - name: show connections again
      debug:
        msg: conns {{ vpn_connections | to_nice_json }}