Support using internal network for clients

Openstack mostly defaults to using public endpoints for
internal communication between services. This patch adds
a new option use-internal-endpoints which, if set to True,
will configure services to use internal endpoints where
possible.

Closes-Bug: 1456876
Change-Id: I76129d4def671c5a5001cf15d9ff629a94a450e0

charmhelpers/contrib/openstack/context.py

@@ -1479,3 +1479,15 @@ class NetworkServiceContext(OSContextGenerator):
                 if self.context_complete(ctxt):
                     return ctxt
         return {}
+
+
+class InternalEndpointContext(OSContextGenerator):
+    """Internal endpoint context.
+
+    This context provides the endpoint type used for communication between
+    services e.g. between Nova and Cinder internally. Openstack uses Public
+    endpoints by default so this allows admins to optionally use internal
+    endpoints.
+    """
+    def __call__(self):
+        return {'use_internal_endpoints': config('use-internal-endpoints')}

config.yaml

@@ -79,6 +79,13 @@ options:
     default: RegionOne
     type: string
     description: OpenStack Region
+  use-internal-endpoints:
+    default: False
+    type: boolean
+    description: |
+      Openstack mostly defaults to using public endpoints for
+      internal communication between services. If set to True this option will
+      configure services to use internal endpoints where possible.
   ceph-osd-replication-count:
     default: 3
     type: int

hooks/glance_utils.py

@@ -174,7 +174,8 @@ CONFIG_FILES = OrderedDict([
                           glance_contexts.MultiStoreContext(),
                           context.OSConfigFlagContext(
                               charm_flag='api-config-flags',
-                              template_flag='api_config_flags')],
+                              template_flag='api_config_flags'),
+                          context.InternalEndpointContext()],
         'services': ['glance-api']
     }),
     (ceph_config_file(), {

templates/icehouse/glance-api.conf

@@ -14,6 +14,10 @@ default_store = file
 
 bind_host = {{ bind_host }}
 
+{% if use_internal_endpoints -%}
+cinder_catalog_info = volumev2::internalURL
+{% endif %}
+
 {% if ext -%}
 bind_port = {{ ext }}
 {% elif bind_port -%}

templates/juno/glance-api.conf

@@ -17,6 +17,10 @@ default_store = file
 
 bind_host = {{ bind_host }}
 
+{% if use_internal_endpoints -%}
+cinder_catalog_info = volumev2::internalURL
+{% endif %}
+
 {% if ext -%}
 bind_port = {{ ext }}
 {% elif bind_port -%}

templates/kilo/glance-api.conf

@@ -5,6 +5,10 @@ debug = {{ debug }}
 workers = {{ workers }}
 bind_host = {{ bind_host }}
 
+{% if use_internal_endpoints -%}
+cinder_catalog_info = volumev2::internalURL
+{% endif %}
+
 {% if ext -%}
 bind_port = {{ ext }}
 {% elif bind_port -%}