Store JSON Home Resources off the composing router

JSON Home Resources must be stored in a location other
than the router for Flask as we are not composing routers
in the same way as we used to with the home-grown webob
based WSGI setup.

Partial-Bug: #1776504
Closes-Bug: #1776506
Change-Id: I292ea9e923ff2f49041dfd417994bcdd797d0520

keystone/common/json_home.py

@@ -12,6 +12,7 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+from oslo_serialization import jsonutils
 
 from keystone import exception
 from keystone.i18n import _
@@ -80,6 +81,36 @@ class Status(object):
             'Unexpected status requested for JSON Home response, %s') % status)
 
 
+class JsonHomeResources(object):
+    """JSON Home resource data."""
+
+    __resources = {}
+    __serialized_resource_data = None
+
+    @classmethod
+    def _reset(cls):
+        # NOTE(morgan): this will reset all json home resource definitions.
+        # This is only used for testing.
+        cls.__resources.clear()
+        cls.__serialized_resource_data = None
+
+    @classmethod
+    def append_resource(cls, rel, data):
+        cls.__resources[rel] = data
+        cls.__serialized_resource_data = None
+
+    @classmethod
+    def resources(cls):
+        # NOTE(morgan): We use a serialized form of the resource data to
+        # ensure that the raw data is not changed by processing, this method
+        # simply populates the serialized store if it is not already populated.
+        # Any changes to this class storage object will result in clearing
+        # the serialized data value.
+        if cls.__serialized_resource_data is None:
+            cls.__serialized_resource_data = jsonutils.dumps(cls.__resources)
+        return {'resources': jsonutils.loads(cls.__serialized_resource_data)}
+
+
 def translate_urls(json_home, new_prefix):
     """Given a JSON Home document, sticks new_prefix on each of the urls."""
     for dummy_rel, resource in json_home['resources'].items():

keystone/common/router.py

@@ -68,6 +68,7 @@ class Router(wsgi.ComposableRouter):
             self.collection_key)
         rel_data = {'href': collection_path, }
         self._resource_descriptions.append((collection_rel, rel_data))
+        json_home.JsonHomeResources.append_resource(collection_rel, rel_data)
 
         if self._is_entity_implemented:
             entity_rel = json_home.build_v3_resource_relation(self.key)
@@ -80,3 +81,5 @@ class Router(wsgi.ComposableRouter):
                 },
             }
             self._resource_descriptions.append((entity_rel, entity_rel_data))
+            json_home.JsonHomeResources.append_resource(
+                entity_rel, entity_rel_data)

keystone/common/wsgi.py

@@ -623,6 +623,7 @@ class RoutersBase(object):
         json_home.Status.update_resource_data(resource_data, status)
 
         self.v3_resources.append((rel, resource_data))
+        json_home.JsonHomeResources.append_resource(rel, resource_data)
 
 
 class V3ExtensionRouter(ExtensionRouter, RoutersBase):

keystone/tests/unit/core.py

@@ -40,6 +40,7 @@ import testtools
 from testtools import testcase
 
 from keystone.common import context
+from keystone.common import json_home
 from keystone.common import provider_api
 from keystone.common import request
 from keystone.common import sql
@@ -685,6 +686,9 @@ class TestCase(BaseTestCase):
         # tests aren't used.
         self.addCleanup(provider_api.ProviderAPIs._clear_registry_instances)
 
+        # Clear the registry of JSON Home Resources
+        self.addCleanup(json_home.JsonHomeResources._reset)
+
         # Ensure Notification subscriptions and resource types are empty
         self.addCleanup(notifications.clear_subscribers)
         self.addCleanup(notifications.reset_notifier)

keystone/version/controllers.py

@@ -12,9 +12,7 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-from oslo_serialization import jsonutils
 from six.moves import http_client
-import webob
 
 from keystone.common import extension
 from keystone.common import json_home
@@ -39,11 +37,7 @@ def request_v3_json_home(new_prefix):
     if 'v3' not in _VERSIONS:
         # No V3 support, so return an empty JSON Home document.
         return {'resources': {}}
-
-    req = webob.Request.blank(
-        '/v3', headers={'Accept': 'application/json-home'})
-    v3_json_home_str = req.get_response(latest_app).body
-    v3_json_home = jsonutils.loads(v3_json_home_str)
+    v3_json_home = json_home.JsonHomeResources.resources()
     json_home.translate_urls(v3_json_home, new_prefix)
 
     return v3_json_home
@@ -180,15 +174,7 @@ class Version(wsgi.Application):
             })
 
     def _get_json_home_v3(self):
-
-        def all_resources():
-            for router in self._routers:
-                for resource in router.v3_resources:
-                    yield resource
-
-        return {
-            'resources': dict(all_resources())
-        }
+        return json_home.JsonHomeResources.resources()
 
     def get_version_v3(self, request):
         versions = self._get_versions_list(request.context_dict)