Don't load the media repo when configured to use an external media repo

changelog.d/5754.feature

@@ -0,0 +1 @@
+Add the `external_media_repo` configuration option. This prevents Synapse from checking or loading media repo specific configuration and from loading in the associated servlets which are not required when a third party media repo is used.

docs/sample_config.yaml

@@ -548,6 +548,21 @@ log_config: "CONFDIR/SERVERNAME.log.config"
 
 
 
+##
+## Media Store
+##
+
+# Is an external media repo in use?
+#
+# Set 'False' to use Synapse's media repo. If this is set to 'True',
+# Synapse's media repo below must be disabled.
+#
+#external_media_repo: False
+
+# Enable the media store service inside Synapse.
+#
+enable_media_repo: True
+
 # Directory where uploaded images and attachments are stored.
 #
 media_store_path: "DATADIR/media_store"

synapse/app/homeserver.py

@@ -219,7 +219,18 @@ def _configure_named_resource(self, name, compress=False):
             )
 
         if name in ["media", "federation", "client"]:
-            if self.get_config().enable_media_repo:
+            if name == "media" and not self.get_config().enable_media_repo:
+                raise ConfigError(
+                    "'media' resource conflicts with enable_media_repo=False"
+                )
+            elif name == "media" and self.get_config().external_media_repo:
+                raise ConfigError(
+                    "'media' resource conflicts with external_media_repo=True"
+                )
+            elif (
+                self.get_config().enable_media_repo
+                and not self.get_config().external_media_repo
+            ):
                 media_repo = self.get_media_repository_resource()
                 resources.update(
                     {
@@ -230,10 +241,6 @@ def _configure_named_resource(self, name, compress=False):
                         ),
                     }
                 )
-            elif name == "media":
-                raise ConfigError(
-                    "'media' resource conflicts with enable_media_repo=False"
-                )
 
         if name in ["keys", "federation"]:
             resources[SERVER_KEY_V2_PREFIX] = KeyApiV2Resource(self)

synapse/app/media_repository.py

@@ -139,6 +139,13 @@ def start(config_options):
 
     assert config.worker_app == "synapse.app.media_repository"
 
+    if config.external_media_repo:
+        _base.quit_with_error(
+            "external_media_repo must be disabled before the \n"
+            "media_repository worker can be used\n"
+            "Please add ``external_media_repo: false`` to the main config\n"
+        )
+
     if config.enable_media_repo:
         _base.quit_with_error(
             "enable_media_repo must be disabled in the main synapse process\n"

synapse/config/repository.py

@@ -12,6 +12,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+
 import os
 from collections import namedtuple
 
@@ -87,6 +88,18 @@ def parse_thumbnail_requirements(thumbnail_sizes):
 
 class ContentRepositoryConfig(Config):
     def read_config(self, config, **kwargs):
+        self.external_media_repo = config.get("external_media_repo", False)
+
+        if self.external_media_repo and self.enable_media_repo:
+            raise ConfigError(
+                "external_media_repo can't be True if the enable_media_repo is True"
+            )
+
+        # If we're using an external media repo, do not load the further
+        # configuration (which checks if files exists).
+        if self.external_media_repo:
+            return
+
         self.max_upload_size = self.parse_size(config.get("max_upload_size", "10M"))
         self.max_image_pixels = self.parse_size(config.get("max_image_pixels", "32M"))
         self.max_spider_size = self.parse_size(config.get("max_spider_size", "10M"))
@@ -202,6 +215,21 @@ def generate_config_section(self, data_dir_path, **kwargs):
 
         return (
             r"""
+        ##
+        ## Media Store
+        ##
+
+        # Is an external media repo in use?
+        #
+        # Set 'False' to use Synapse's media repo. If this is set to 'True',
+        # Synapse's media repo below must be disabled.
+        #
+        #external_media_repo: False
+
+        # Enable the media store service inside Synapse.
+        #
+        enable_media_repo: True
+
         # Directory where uploaded images and attachments are stored.
         #
         media_store_path: "%(media_store)s"

synapse/rest/admin/__init__.py

@@ -825,7 +825,6 @@ def register_servlets(hs, http_server):
 def register_servlets_for_client_rest_resource(hs, http_server):
     """Register only the servlets which need to be exposed on /_matrix/client/xxx"""
     WhoisRestServlet(hs).register(http_server)
-    PurgeMediaCacheRestServlet(hs).register(http_server)
     PurgeHistoryStatusRestServlet(hs).register(http_server)
     DeactivateAccountRestServlet(hs).register(http_server)
     PurgeHistoryRestServlet(hs).register(http_server)
@@ -834,10 +833,15 @@ def register_servlets_for_client_rest_resource(hs, http_server):
     GetUsersPaginatedRestServlet(hs).register(http_server)
     SearchUsersRestServlet(hs).register(http_server)
     ShutdownRoomRestServlet(hs).register(http_server)
-    QuarantineMediaInRoom(hs).register(http_server)
-    ListMediaInRoom(hs).register(http_server)
     UserRegisterServlet(hs).register(http_server)
     DeleteGroupAdminRestServlet(hs).register(http_server)
     AccountValidityRenewServlet(hs).register(http_server)
+
+    # Media URLs -- if we're using an external media repo, don't add them.
+    if not hs.config.external_media_repo:
+        PurgeMediaCacheRestServlet(hs).register(http_server)
+        QuarantineMediaInRoom(hs).register(http_server)
+        ListMediaInRoom(hs).register(http_server)
+
     # don't add more things here: new servlets should only be exposed on
     # /_synapse/admin so should not go here. Instead register them in AdminRestResource.

synapse/rest/media/v1/media_repository.py

@@ -753,8 +753,12 @@ class MediaRepositoryResource(Resource):
     """
 
     def __init__(self, hs):
-        Resource.__init__(self)
+        # If this is not the media repo (which will always load this class),
+        # raise an exception if it is tried to be used.
+        if hs.config.external_media_repo:
+            raise Exception("This Synapse is not configured for media repo use.")
 
+        super().__init__()
         media_repo = hs.get_media_repository()
 
         self.putChild(b"upload", UploadResource(hs, media_repo))