---
- name: Determine whether host is in Region 1
  set_fact:
    region: 'dc-1'
  when: groups['dc-1'] is defined and inventory_hostname in groups['dc-1']

- name: Determine whether host is in Region 2
  set_fact:
    region: 'dc-2'
  when: groups['dc-2'] is defined and inventory_hostname in groups['dc-2']

- name: Determine whether host is in Region 3
  set_fact:
    region: 'dc-3'
  when: groups['dc-3'] is defined and inventory_hostname in groups['dc-3']

- name: Set default region if not set
  set_fact:
    region: 'dc-1'
  when: region is not defined or region | trim | length == 0

- name: Add region to cache
  cache:
    key: "region"
    value: "{{ region }}"