support for non 22 ssh and compute node mgt bridge

Change-Id: I3eca34de01238c4a29906ffa9db1f3e37a661141
diff --git a/roles/compute-node/vars/main.yml b/roles/compute-node/vars/main.yml
index 1906b70..64316c3 100644
--- a/roles/compute-node/vars/main.yml
+++ b/roles/compute-node/vars/main.yml
@@ -3,8 +3,8 @@
 compute_node:
     interfaces:
         fabric: "{{ fabric_iface | default('fabric') }}"
-        management: "{{ management_iface | default('eth2') }}"
-        external: "{{ external_iface | default('eth3') }}"
+        management: "{{ management_iface | default('br-mgmt') }}"
+        external: "{{ external_iface | default('') }}"
     addresses:
         fabric: "{{ fabric_ip | mandatory }}"
         management: "{{ management_ip | default('dhcp') }}"