roles/interface-config/templates/eth.cfg.j2

{% for node in physical_node_list if node.name == ansible_hostname %}
auto {{ node.interface | default(mgmt_interface) }}

iface {{ node.interface | default(mgmt_interface) }} inet static
    address {{ mgmt_ipv4_first_octets }}.{{ node.ipv4_last_octet }}
    network {{ mgmt_ipv4_first_octets }}.0
    netmask 255.255.255.0
    broadcast {{ mgmt_ipv4_first_octets }}.255
{% if node.gateway_enabled is defined and node.gateway_enabled %}
    gateway {{ mgmt_ipv4_first_octets }}.1
{% endif %}
{% endfor %}