[CORD-1650]
Refactor interface/bridge handling

Change-Id: I83fd9eb3e8440ba277b7b4d1ed41cb18347b6916
diff --git a/roles/create-lxd/tasks/main.yml b/roles/create-lxd/tasks/main.yml
index a9d2ec6..ce614ed 100644
--- a/roles/create-lxd/tasks/main.yml
+++ b/roles/create-lxd/tasks/main.yml
@@ -1,4 +1,4 @@
-
+---
 # Copyright 2017-present Open Networking Foundation
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -13,8 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-
----
 # file: create-lxd/tasks/main.yml
 
 - name: Enable trusty-backports apt repository
@@ -44,10 +42,9 @@
     devices:
       eth0:
         type: nic
-        parent: mgmtbr
+        parent: "{{ management_net_bridge }}"
         nictype: bridged
-        # ipv4.address: "{{ mgmt_ipv4_first_octets }}.{{ item.ipv4_last_octet }}"
-        hwaddr: "{{ item.hwaddr | default(hwaddr_prefix ~ ((mgmt_ipv4_first_octets ~ '.' ~ item.ipv4_last_octet) | ip4_hex)) | hwaddr('unix') }}"
+        hwaddr: "{{ item.hwaddr | default( vtn_net_management_host_hwaddr_prefix ~ ( vtn_net_management_host_cidr | ipaddr(item.ipv4_last_octet) | ipaddr('address') | ip4_hex )) | hwaddr('unix') }}"
       certs:
         type: disk
         path: /usr/local/share/ca-certificates/cord/