Add ability to set OS_INTERFACE

In some cases when controller doesn't have routing to public endpoints
we need to be able to set OS_INTERFACE strictly, as default is public.
This patch adds such ability.

Change-Id: If09ff4d88333ab14a0ff0959e0b8e84add7ca3b4
Related-Prod: PROD-16197
diff --git a/keystone/files/keystonerc b/keystone/files/keystonerc
index 15634a2..c91d196 100644
--- a/keystone/files/keystonerc
+++ b/keystone/files/keystonerc
@@ -6,5 +6,8 @@
 export OS_REGION_NAME={{ server.region }}
 export OS_SERVICE_TOKEN={{ server.service_token }}
 export OS_SERVICE_ENDPOINT="http://{{ server.bind.private_address }}:{{ server.bind.private_port }}/v2.0/"
-export OS_ENDPOINT_TYPE="internal"
+{%- if server.interface is defined %}
+export OS_INTERFACE={{ server.interface }}
+{%- endif %}
+export OS_ENDPOINT_TYPE={{ server.get('interface', 'internal') }}
 export OS_CACERT="{{ server.cacert }}"