Remove the experimental spaces enabled flag. (matrix-org#10063)

In lieu of just always enabling the unstable spaces endpoint and
unstable room version.

changelog.d/10063.removal

@@ -0,0 +1 @@
+Remove the experimental `spaces_enabled` flag. The spaces features are always available now.

docs/sample_config.yaml

@@ -2916,18 +2916,3 @@ redis:
   # Optional password if configured on the Redis instance
   #
   #password: <secret_password>
-
-
-# Enable experimental features in Synapse.
-#
-# Experimental features might break or be removed without a deprecation
-# period.
-#
-experimental_features:
-  # Support for Spaces (MSC1772), it enables the following:
-  #
-  # * The Spaces Summary API (MSC2946).
-  # * Restricting room membership based on space membership (MSC3083).
-  #
-  # Uncomment to disable support for Spaces.
-  #spaces_enabled: false

synapse/api/room_versions.py

@@ -181,6 +181,6 @@ class RoomVersions:
         RoomVersions.V5,
         RoomVersions.V6,
         RoomVersions.MSC2176,
+        RoomVersions.MSC3083,
     )
-    # Note that we do not include MSC3083 here unless it is enabled in the config.
 }  # type: Dict[str, RoomVersion]

synapse/config/experimental.py

@@ -12,7 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from synapse.api.room_versions import KNOWN_ROOM_VERSIONS, RoomVersions
 from synapse.config._base import Config
 from synapse.types import JsonDict
 
@@ -28,27 +27,5 @@ def read_config(self, config: JsonDict, **kwargs):
         # MSC2858 (multiple SSO identity providers)
         self.msc2858_enabled = experimental.get("msc2858_enabled", False)  # type: bool
 
-        # Spaces (MSC1772, MSC2946, MSC3083, etc)
-        self.spaces_enabled = experimental.get("spaces_enabled", True)  # type: bool
-        if self.spaces_enabled:
-            KNOWN_ROOM_VERSIONS[RoomVersions.MSC3083.identifier] = RoomVersions.MSC3083
-
         # MSC3026 (busy presence state)
         self.msc3026_enabled = experimental.get("msc3026_enabled", False)  # type: bool
-
-    def generate_config_section(self, **kwargs):
-        return """\
-        # Enable experimental features in Synapse.
-        #
-        # Experimental features might break or be removed without a deprecation
-        # period.
-        #
-        experimental_features:
-          # Support for Spaces (MSC1772), it enables the following:
-          #
-          # * The Spaces Summary API (MSC2946).
-          # * Restricting room membership based on space membership (MSC3083).
-          #
-          # Uncomment to disable support for Spaces.
-          #spaces_enabled: false
-        """

synapse/federation/transport/server.py

@@ -1562,13 +1562,12 @@ def register_servlets(
                 server_name=hs.hostname,
             ).register(resource)
 
-        if hs.config.experimental.spaces_enabled:
-            FederationSpaceSummaryServlet(
-                handler=hs.get_space_summary_handler(),
-                authenticator=authenticator,
-                ratelimiter=ratelimiter,
-                server_name=hs.hostname,
-            ).register(resource)
+        FederationSpaceSummaryServlet(
+            handler=hs.get_space_summary_handler(),
+            authenticator=authenticator,
+            ratelimiter=ratelimiter,
+            server_name=hs.hostname,
+        ).register(resource)
 
     if "openid" in servlet_groups:
         for servletclass in OPENID_SERVLET_CLASSES:

synapse/rest/client/v1/room.py

@@ -1060,9 +1060,7 @@ def register_servlets(hs: "HomeServer", http_server, is_worker=False):
     RoomRedactEventRestServlet(hs).register(http_server)
     RoomTypingRestServlet(hs).register(http_server)
     RoomEventContextServlet(hs).register(http_server)
-
-    if hs.config.experimental.spaces_enabled:
-        RoomSpaceSummaryRestServlet(hs).register(http_server)
+    RoomSpaceSummaryRestServlet(hs).register(http_server)
 
     # Some servlets only get registered for the main process.
     if not is_worker: