Support GET account_data requests on a worker (#7311)

changelog.d/7311.doc

+Document that account_data get requests can be routed to a worker.

docs/workers.md

@@ -268,6 +268,8 @@ Additionally, the following REST endpoints can be handled for GET requests:
 
     ^/_matrix/client/(api/v1|r0|unstable)/pushrules/.*$
     ^/_matrix/client/(api/v1|r0|unstable)/groups/.*$
+    ^/_matrix/client/(api/v1|r0|unstable)/user/[^/]*/account_data/
+    ^/_matrix/client/(api/v1|r0|unstable)/user/[^/]*/rooms/[^/]*/account_data/
 
 Additionally, the following REST endpoints can be handled, but all requests must
 be routed to the same instance:

synapse/app/generic_worker.py

@@ -98,6 +98,10 @@ from synapse.rest.client.v1.voip import VoipRestServlet
 from synapse.rest.client.v2_alpha import groups, sync, user_directory
 from synapse.rest.client.v2_alpha._base import client_patterns
 from synapse.rest.client.v2_alpha.account import ThreepidRestServlet
+from synapse.rest.client.v2_alpha.account_data import (
+    AccountDataServlet,
+    RoomAccountDataServlet,
+)
 from synapse.rest.client.v2_alpha.keys import KeyChangesServlet, KeyQueryServlet
 from synapse.rest.client.v2_alpha.register import RegisterRestServlet
 from synapse.rest.client.versions import VersionsRestServlet
@@ -475,6 +479,8 @@ class GenericWorkerServer(HomeServer):
                     ProfileDisplaynameRestServlet(self).register(resource)
                     ProfileRestServlet(self).register(resource)
                     KeyUploadServlet(self).register(resource)
+                    AccountDataServlet(self).register(resource)
+                    RoomAccountDataServlet(self).register(resource)
 
                     sync.register_servlets(self, resource)
                     events.register_servlets(self, resource)

synapse/rest/client/v2_alpha/account_data.py

@@ -38,8 +38,12 @@ class AccountDataServlet(RestServlet):
         self.auth = hs.get_auth()
         self.store = hs.get_datastore()
         self.notifier = hs.get_notifier()
+        self._is_worker = hs.config.worker_app is not None
 
     async def on_PUT(self, request, user_id, account_data_type):
+        if self._is_worker:
+            raise Exception("Cannot handle PUT /account_data on worker")
+
         requester = await self.auth.get_user_by_req(request)
         if user_id != requester.user.to_string():
             raise AuthError(403, "Cannot add account data for other users.")
@@ -86,8 +90,12 @@ class RoomAccountDataServlet(RestServlet):
         self.auth = hs.get_auth()
         self.store = hs.get_datastore()
         self.notifier = hs.get_notifier()
+        self._is_worker = hs.config.worker_app is not None
 
     async def on_PUT(self, request, user_id, room_id, account_data_type):
+        if self._is_worker:
+            raise Exception("Cannot handle PUT /account_data on worker")
+
         requester = await self.auth.get_user_by_req(request)
         if user_id != requester.user.to_string():
             raise AuthError(403, "Cannot add account data for other users.")