Move MSC3030 `/timestamp_to_event` endpoint to stable v1 location (#14471)

Fix https://github.com/matrix-org/synapse/issues/14390

 - Client API: `/_matrix/client/unstable/org.matrix.msc3030/rooms/<roomID>/timestamp_to_event?ts=<timestamp>&dir=<direction>` -> `/_matrix/client/v1/rooms/<roomID>/timestamp_to_event?ts=<timestamp>&dir=<direction>`
 - Federation API: `/_matrix/federation/unstable/org.matrix.msc3030/timestamp_to_event/<roomID>?ts=<timestamp>&dir=<direction>` -> `/_matrix/federation/v1/timestamp_to_event/<roomID>?ts=<timestamp>&dir=<direction>`

Complement test changes: https://github.com/matrix-org/complement/pull/559

4 files changed, 14 insertions, 14 deletions

diff --git a/synapse/federation/federation_client.py b/synapse/federation/federation_client.py
index c4c0bc7315..8bccc9c60d 100644
--- a/synapse/federation/federation_client.py
+++ b/synapse/federation/federation_client.py
@@ -1691,9 +1691,19 @@ class FederationClient(FederationBase):
                 #   to return events on *both* sides of the timestamp to
                 #   help reconcile the gap faster.
                 _timestamp_to_event_from_destination,
+                # Since this endpoint is new, we should try other servers before giving up.
+                # We can safely remove this in a year (remove after 2023-11-16).
+                failover_on_unknown_endpoint=True,
             )
             return timestamp_to_event_response
-        except SynapseError:
+        except SynapseError as e:
+            logger.warn(
+                "timestamp_to_event(room_id=%s, timestamp=%s, direction=%s): encountered error when trying to fetch from destinations: %s",
+                room_id,
+                timestamp,
+                direction,
+                e,
+            )
             return None
 
     async def _timestamp_to_event_from_destination(
diff --git a/synapse/federation/transport/client.py b/synapse/federation/transport/client.py
index a3cfc701cd..77f1f39cac 100644
--- a/synapse/federation/transport/client.py
+++ b/synapse/federation/transport/client.py
@@ -185,9 +185,8 @@ class TransportLayerClient:
         Raises:
             Various exceptions when the request fails
         """
-        path = _create_path(
-            FEDERATION_UNSTABLE_PREFIX,
-            "/org.matrix.msc3030/timestamp_to_event/%s",
+        path = _create_v1_path(
+            "/timestamp_to_event/%s",
             room_id,
         )
 
diff --git a/synapse/federation/transport/server/__init__.py b/synapse/federation/transport/server/__init__.py
index 50623cd385..2725f53cf6 100644
--- a/synapse/federation/transport/server/__init__.py
+++ b/synapse/federation/transport/server/__init__.py
@@ -25,7 +25,6 @@ from synapse.federation.transport.server._base import (
 from synapse.federation.transport.server.federation import (
     FEDERATION_SERVLET_CLASSES,
     FederationAccountStatusServlet,
-    FederationTimestampLookupServlet,
 )
 from synapse.http.server import HttpServer, JsonResource
 from synapse.http.servlet import (
@@ -291,13 +290,6 @@ def register_servlets(
             )
 
         for servletclass in SERVLET_GROUPS[servlet_group]:
-            # Only allow the `/timestamp_to_event` servlet if msc3030 is enabled
-            if (
-                servletclass == FederationTimestampLookupServlet
-                and not hs.config.experimental.msc3030_enabled
-            ):
-                continue
-
             # Only allow the `/account_status` servlet if msc3720 is enabled
             if (
                 servletclass == FederationAccountStatusServlet
diff --git a/synapse/federation/transport/server/federation.py b/synapse/federation/transport/server/federation.py
index 205fd16daa..53e77b4bb6 100644
--- a/synapse/federation/transport/server/federation.py
+++ b/synapse/federation/transport/server/federation.py
@@ -218,14 +218,13 @@ class FederationTimestampLookupServlet(BaseFederationServerServlet):
     `dir` can be `f` or `b` to indicate forwards and backwards in time from the
     given timestamp.
 
-    GET /_matrix/federation/unstable/org.matrix.msc3030/timestamp_to_event/<roomID>?ts=<timestamp>&dir=<direction>
+    GET /_matrix/federation/v1/timestamp_to_event/<roomID>?ts=<timestamp>&dir=<direction>
     {
         "event_id": ...
     }
     """
 
     PATH = "/timestamp_to_event/(?P<room_id>[^/]*)/?"
-    PREFIX = FEDERATION_UNSTABLE_PREFIX + "/org.matrix.msc3030"
 
     async def on_GET(
         self,