Build MediaRepositoryResource as a homeserver dependency

This avoids the scenario where we have four different PreviewUrlResources
configured on a single app, each of which have their own caches and cache
clearing jobs.

synapse/app/homeserver.py

@@ -43,7 +43,6 @@ from synapse.rest import ClientRestResource
 from synapse.rest.key.v1.server_key_resource import LocalKey
 from synapse.rest.key.v2 import KeyApiV2Resource
 from synapse.rest.media.v0.content_repository import ContentRepoResource
-from synapse.rest.media.v1.media_repository import MediaRepositoryResource
 from synapse.server import HomeServer
 from synapse.storage import are_all_users_on_domain
 from synapse.storage.engines import IncorrectDatabaseSetup, create_engine
@@ -195,7 +194,7 @@ class SynapseHomeServer(HomeServer):
             })
 
         if name in ["media", "federation", "client"]:
-            media_repo = MediaRepositoryResource(self)
+            media_repo = self.get_media_repository_resource()
             resources.update({
                 MEDIA_PREFIX: media_repo,
                 LEGACY_MEDIA_PREFIX: media_repo,

synapse/app/media_repository.py

@@ -35,7 +35,6 @@ from synapse.replication.slave.storage.registration import SlavedRegistrationSto
 from synapse.replication.slave.storage.transactions import TransactionStore
 from synapse.replication.tcp.client import ReplicationClientHandler
 from synapse.rest.media.v0.content_repository import ContentRepoResource
-from synapse.rest.media.v1.media_repository import MediaRepositoryResource
 from synapse.server import HomeServer
 from synapse.storage.engines import create_engine
 from synapse.storage.media_repository import MediaRepositoryStore
@@ -89,7 +88,7 @@ class MediaRepositoryServer(HomeServer):
                 if name == "metrics":
                     resources[METRICS_PREFIX] = MetricsResource(self)
                 elif name == "media":
-                    media_repo = MediaRepositoryResource(self)
+                    media_repo = self.get_media_repository_resource()
                     resources.update({
                         MEDIA_PREFIX: media_repo,
                         LEGACY_MEDIA_PREFIX: media_repo,

synapse/server.py

@@ -60,7 +60,10 @@ from synapse.http.matrixfederationclient import MatrixFederationHttpClient
 from synapse.notifier import Notifier
 from synapse.push.action_generator import ActionGenerator
 from synapse.push.pusherpool import PusherPool
-from synapse.rest.media.v1.media_repository import MediaRepository
+from synapse.rest.media.v1.media_repository import (
+    MediaRepository,
+    MediaRepositoryResource,
+)
 from synapse.state import StateHandler
 from synapse.storage import DataStore
 from synapse.streams.events import EventSources
@@ -121,6 +124,7 @@ class HomeServer(object):
         'http_client_context_factory',
         'simple_http_client',
         'media_repository',
+        'media_repository_resource',
         'federation_transport_client',
         'federation_sender',
         'receipts_handler',
@@ -293,6 +297,11 @@ class HomeServer(object):
             **self.db_config.get("args", {})
         )
 
+    def build_media_repository_resource(self):
+        # build the media repo resource. This indirects through the HomeServer
+        # to ensure that we only have a single instance of
+        return MediaRepositoryResource(self)
+
     def build_media_repository(self):
         return MediaRepository(self)
 

synapse/server.pyi

@@ -5,6 +5,7 @@ import synapse.handlers
 import synapse.handlers.auth
 import synapse.handlers.device
 import synapse.handlers.e2e_keys
+import synapse.rest.media.v1.media_repository
 import synapse.storage
 import synapse.state
 
@@ -35,3 +36,9 @@ class HomeServer(object):
 
     def get_federation_transport_client(self) -> synapse.federation.transport.client.TransportLayerClient:
         pass
+
+    def get_media_repository_resource(self) -> synapse.rest.media.v1.media_repository.MediaRepositoryResource:
+        pass
+
+    def get_media_repository(self) -> synapse.rest.media.v1.media_repository.MediaRepository:
+        pass