Validate IPv4 address in lists of interfaces

site.yml

- hosts: localhost
  gather_facts: false
  tasks:
  - name: Define some data
    ansible.builtin.set_fact:
      data:
        wan:
          - name: LAN3
            ipv4-address: 100.100.100.1
            subnet-mask: 255.255.255.248
            gateway: 100.100.100.2
          - name: LAN4
            ipv4-address: 1.2.3.4
            subnet-mask: 255.255.255.0
            gateway: 1.2.3.4
        ha:
          - name: LAN10
            ipv4-address: 169.254.9.1
            subnet-mask: 255.255.255.252
        vlan:
          - id:
            ipv4-address:
            subnet-mask:
        mgmt:
          - name: Mgmt
            ipv4-address:
            subnet-mask:
        invalid:
          - name:
            ipv4-address: 256.256.256.256
            subnet-mask:
  - name: Walk the interfaces of each group
    ansible.builtin.include_tasks:
      file: validate_interfaces.yml
    loop: "{{ data|dict2items }}"
    loop_control:
      loop_var: group_tuple
    vars:
      group: "{{ group_tuple.key }}"
      interfaces: "{{ group_tuple.value }}"

validate_interface.yml

- name: >-
    Validate an interface has a valid IPv4 address or none:
    '{{ group }}/{{ name }}'
  ansible.builtin.assert:
    that: is_ipv4 or is_none
    success_msg: >-
      Interface '{{ name }}' in group '{{ group }}'
      has a valid IPv4 address: {{ ip_address }}
    fail_msg: >-
      Interface '{{ name }}' in group '{{ group }}'
      has an invalid IPv4 address: {{ ip_address }}
  vars:
    interface_name: "{{ interface['name']|default(none) }}"
    interface_id: "{{ interface['id']|default(none) }}"
    name: "{{ interface_name or interface_id or 'unknown' }}"
    ip_address: "{{ interface['ipv4-address'] }}"
    is_ipv4: "{{ interface['ipv4-address'] is ansible.utils.ipv4_address }}"
    is_none: "{{ interface['ipv4-address'] is none }}"

validate_interfaces.yml

- name: "Validate a group of interfaces: '{{ group }}'"
  ansible.builtin.include_tasks:
    file: validate_interface.yml
  loop: "{{ interfaces }}"
  loop_control:
    loop_var: interface