add mtu to container

juno-icehouse-networks.yml

# Modified from file os-ansible-deployment/blob/juno/rpc_deployment/roles/container_common/templates/container_interface_file.j2

{%- set used_interfaces = [] %}
{%- for net in provider_networks %}
  {%- if net.network.container_interface not in used_interfaces %}
    {%- for group in net.network.group_binds if group in hostvars[inventory_hostname]['group_names'] %}
      {%- if net.network.container_interface not in used_interfaces %}
        {%- if used_interfaces.append(net.network.container_interface) %}{%- endif %}
      {%- endif %}
    {%- endfor %}
{% if net.network.container_interface in used_interfaces %}
{% if net.network.container_bridge != management_bridge %}
auto {{ net.network.container_interface }}
  {% if 'ip_from_q' in net.network and hostvars[inventory_hostname][net.network.ip_from_q + '_address'] is defined %}
iface {{ net.network.container_interface }} inet static
    address {{ hostvars[inventory_hostname][net.network.ip_from_q + '_address'] }}
    netmask {{ net.network.subnetmask|default(hostvars[inventory_hostname][net.network.ip_from_q + '_netmask']) }}
    mtu {{ net.network.mtu | default(1500) }}
  {% else %}
iface {{ net.network.container_interface }} inet manual
  {% endif %}
{% endif %}
{% endif %}

{% endif %}
{% endfor %}

# Used Devices: {{ used_interfaces }}

master-kilo-user_vars.yaml

# The container interface variable is a a default object that assume the
# Ansible iterator type is `with_dict`.
lxc_container_interface: |
  ### start generated network for [ {{ item.value.interface }} ] ###
  auto {{ item.value.interface }}
  {% if item.value.address is defined %}
  iface {{ item.value.interface }} inet static
      address {{ item.value.address }}
      netmask {{ item.value.netmask }}
  {% if item.value.gateway is defined %}
      gateway {{ item.value.gateway }}
  {% endif %}
  mtu {{ item.value.mtu | default(1500) }}
  {% else %}
  iface {{ item.value.interface }} inet manual
  {% endif %}
  ### end generated network for [ {{ item.value.interface }} ] ###