Add ability to dynamically generate gateway external address

Currently reclass classify command fails to generate gateway
external ip dynamically, because it's hardcoded in reclass,
this patch fixes this.

Change-Id: I0f8424cf4546cd0d3d4371f09640db311af9c2bb
diff --git a/classes/cluster/virtual-mcp-pike-ovs/infra/config.yml b/classes/cluster/virtual-mcp-pike-ovs/infra/config.yml
index 697e6bd..815e20f 100644
--- a/classes/cluster/virtual-mcp-pike-ovs/infra/config.yml
+++ b/classes/cluster/virtual-mcp-pike-ovs/infra/config.yml
@@ -121,6 +121,8 @@
           cluster_param:
             openstack_gateway_address:
               value_template: <<node_control_ip>>
+            openstack_gateway_node01_external_address:
+              value_template: <<node_external_ip>>
         openstack_dashboard:
           expression: <<node_hostname>>__startswith__prx
           node_class:
@@ -189,7 +191,7 @@
         openstack_gateway_node01:
           params:
             tenant_address: 10.1.0.110
-            external_address: 10.16.0.110
+            external_address: ${_param:openstack_gateway_node01_external_address}
         openstack_share_node01:
           params:
             single_address: 172.16.10.130
diff --git a/classes/cluster/virtual-mcp-pike-ovs/openstack/init.yml b/classes/cluster/virtual-mcp-pike-ovs/openstack/init.yml
index 487dd65..b813a5d 100644
--- a/classes/cluster/virtual-mcp-pike-ovs/openstack/init.yml
+++ b/classes/cluster/virtual-mcp-pike-ovs/openstack/init.yml
@@ -22,6 +22,7 @@
     openstack_message_queue_node03_address: ${_param:openstack_control_node03_address}
     openstack_gateway_address: 172.16.10.110
     openstack_gateway_node01_address: ${_param:openstack_gateway_address}
+    openstack_gateway_node01_external_address: 10.16.0.110
     openstack_dns_node01_address: 172.16.10.111
     openstack_dns_node02_address: 172.16.10.112
     openstack_share_node01_address: 172.16.10.130