iiab/roles/network/tasks/sysd-netd-debian.yml

# sysd-netd-debian.yml
- name: Copy the bridge script - Creates br0
  template:
    dest: /etc/systemd/network/IIAB-Bridge.netdev
    src: network/systemd-br0.j2
  when: iiab_lan_iface == "br0"

- name: Copy the bridge script - Assigns IP address
  template:
    dest: /etc/systemd/network/IIAB-Bridge.network
    src: network/systemd-br0-network.j2
  when: iiab_lan_iface == "br0"

- name: Copy the bridge script - Assigns br0 wired slaves
  template:
    dest: /etc/systemd/network/IIAB-Slave.network
    src: network/systemd-br0-slave.j2
  when: iiab_wired_lan_iface is defined and iiab_lan_iface == "br0"

- name: Stopping services
  include_tasks: down-debian.yml

- name: Disable and mask systemd-networkd-wait-online
  systemd:
    name: systemd-networkd-wait-online
    enabled: no
    masked: yes
    state: stopped
  when: is_ubuntu_18

- name: Static IP computing CIDR
  shell: netmask {{ wan_ip }}/{{ wan_netmask }} | awk -F "/" '{print $2}'
  register: CIDR
  when: wan_ip != "dhcp"

- name: Static IP setting CIDR
  set_fact:
    wan_cidr: "{{ CIDR.stdout }}"
  when: wan_ip != "dhcp"

# ICO will always set gui_static_wan_ip away from the default of 'unset' while
# gui_static_wan turns dhcp on/off through wan_ip in computed_network and
# overrides gui_static_wan_ip that is present. Changing wan_ip in local_vars
# is a oneway street to static.
- name: Supply static template
  template:
    dest:  /etc/netplan/50-cloud-init.yaml
    src: network/cloud-init.j2
    backup: no
  when: wan_ip != "dhcp" or gui_static_wan_ip == "undefined"

- name: Reload systemd
  systemd:
    daemon_reload: yes

- name: Restart the systemd-networkd service
  systemd:
    name: systemd-networkd
    enabled: yes
    state: restarted
  when: not nobridge is defined and not no_net_restart