Openstack broken metadata interfaces template

Was my 2nd time hitting the same issue and it wasted my whole day so I think I should document this as a note just in case it happens again.

In case you are seeing something like this from your metadata (be it metadata server, or config-drive), in this example I mounted the config drive as /mnt.

# cat /mnt/openstack/content/0000
DEVICE="{{ name }}"
NM_CONTROLLED="no"
ONBOOT=yes
TYPE=Ethernet
BOOTPROTO=static
IPADDR={{ address }}
NETMASK={{ netmask }}
BROADCAST={{ broadcast }}
GATEWAY={{ gateway }}
DNS1={{ dns }}

#if $use_ipv6
IPV6INIT=yes
IPV6ADDR={{ address_v6 }}
#end if

Chances that you are hitting this bug.

As cloud-init doesnt really recognize format like that, to fix the issue you will need to update the template /usr/share/nova/interfaces.template (assuming you are on CentOS/RHEL7) with something like this which is a debian-ish template

# Injected by Nova on instance boot
#
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).
# The loopback network interface
auto lo
iface lo inet loopback
{% for ifc in interfaces -%}
auto {{ ifc.name }}
iface {{ ifc.name }} inet static
address {{ ifc.address }}
netmask {{ ifc.netmask }}
broadcast {{ ifc.broadcast }}
{%- if ifc.gateway %}
gateway {{ ifc.gateway }}
{%- endif %}
{%- if ifc.dns %}
dns-nameservers {{ ifc.dns }}
{%- endif %}
{% if use_ipv6 -%}
iface {{ ifc.name }} inet6 static
address {{ ifc.address_v6 }}
netmask {{ ifc.netmask_v6 }}
{%- if ifc.gateway_v6 %}
gateway {{ ifc.gateway_v6 }}
{%- endif %}
{%- endif %}
{%- endfor %}