---
- name: Apply overrides
  ansible.builtin.import_playbook: >-
    {{ lookup("ansible.builtin.env", "MOLECULE_SCENARIO_DIRECTORY") }}/overrides.yml

- name: Configure dual-stack networking
  hosts: all
  become: true

  # Unfortunately, as of 2022-09, Vagrant does not support the configuration
  # of both IPv4 and IPv6 addresses for a single network adapter. So we have
  # to configure that ourselves.
  # Moreover, we have to explicitly enable IPv6 for the loopback interface.

  tasks:
    - name: Enable IPv6 for network interfaces
      ansible.posix.sysctl:
        name: net.ipv6.conf.{{ item }}.disable_ipv6
        value: "0"
      with_items:
        - all
        - default
        - lo

    - name: Disable duplicate address detection
      # Duplicate address detection did repeatedly fail within the virtual
      # network. But since this setup does not use SLAAC anyway, we can safely
      # disable it.
      ansible.posix.sysctl:
        name: net.ipv6.conf.{{ item }}.accept_dad
        value: "0"
      with_items:
        - "{{ flannel_iface }}"

    - name: Write IPv4 configuration
      ansible.builtin.template:
        src: 55-flannel-ipv4.yaml.j2
        dest: /etc/netplan/55-flannel-ipv4.yaml
        owner: root
        group: root
        mode: "0644"
      register: netplan_template

    - name: Apply netplan configuration
      # Conceptually, this should be a handler rather than a task.
      # However, we are currently not in a role context - creating
      # one just for this seemed overkill.
      when: netplan_template.changed
      ansible.builtin.command:
        cmd: netplan apply
      changed_when: true