Do not set the cell endpoints for regular split-controlplane child stacks

When we deploy a nova cell child stack we have to redirect some endpoints to
the local instance instead of the central instance.
For non-nova cell child stacks we must disable this.

Closes-bug: 1823992
Change-Id: If39def80959ad91d96d92882f60e0e4c23b9b85e

overcloud.j2.yaml

@@ -151,6 +151,11 @@ parameters:
     description: Maxiumum batch size for creating nodes
     type: number
 
+  NovaAdditionalCell:
+    default: false
+    description: Whether this is an cell additional to the default cell.
+    type: boolean
+
   # Jinja loop for Role in role_data.yaml
 {% for role in roles %}
   {{role.name}}ExtraConfig:
@@ -284,6 +289,30 @@ conditions:
       equals:
         - get_param: RedisVirtualFixedIPs
         - []
+  set_default_mysql_cell_internal:
+    or:
+      - equals:
+        - get_param: NovaAdditionalCell
+        - true
+      - and:
+        - equals:
+          - get_param: NovaAdditionalCell
+          - false
+        - equals:
+          - get_param: [EndpointMapOverride, MysqlCellInternal]
+          - ''
+  set_default_nova_vnc_proxy_cell_public:
+    or:
+      - equals:
+        - get_param: NovaAdditionalCell
+        - true
+      - and:
+        - equals:
+          - get_param: NovaAdditionalCell
+          - false
+        - equals:
+          - get_param: [EndpointMapOverride, NovaVNCProxyCellPublic]
+          - ''
 
 resources:
 
@@ -390,8 +419,19 @@ resources:
         map_merge:
           - {get_attr: [EndpointMap, endpoint_map]}
           - {get_param: EndpointMapOverride}
-          - MysqlCellInternal: {get_attr: [EndpointMap, endpoint_map, MysqlInternal]}
+            # For parent stack we must set these to the local endpoints
-          - NovaVNCProxyCellPublic: {get_attr: [EndpointMap, endpoint_map, NovaVNCProxyPublic]}
+            # For split-controlplane stacks that are nova cells we must set
+            # these to the local endpoints
+            # For split-controlplane stacks that are not nova cells we should
+            # take these from EndpointMapOverride (i.e the parent stack)
+          - if:
+            - set_default_mysql_cell_internal
+            - MysqlCellInternal: {get_attr: [EndpointMap, endpoint_map, MysqlInternal]}
+            - {}
+          - if:
+            - set_default_nova_vnc_proxy_cell_public
+            - NovaVNCProxyCellPublic: {get_attr: [EndpointMap, endpoint_map, NovaVNCProxyPublic]}
+            - {}
 
   SshKnownHostsConfig:
     type: OS::TripleO::Ssh::KnownHostsConfig