playbooks/roles/create-libvirt-networks/templates/libvirt-net.xml.j2

<network>
  <name>{{ item.key }}</name>
  {% if item.key == 'public' %}
  <forward mode='nat'>
    <nat>
      <port start='1024' end='65535'/>
    </nat>
  </forward>
  {% endif %}
  <bridge name='br_{{ item.key }}' stp='on' delay='0'/>
  <ip address='{{ item.value.network | regex_replace(".0$", ".1") }}' netmask='255.255.255.0'>
    <dhcp>
      <range start='{{ item.value.network | regex_replace(".0$", ".2") }}' end='{{ item.value.network | regex_replace(".0$", ".200") }}'/>
    </dhcp>
  </ip>
</network>