Fix a bug introduced in Synapse v1.84.0 where workers do not start up when no instance_map was provided.

.github/workflows/tests.yml

@@ -314,6 +314,7 @@ jobs:
       # There aren't wheels for some of the older deps, so we need to install
       # their build dependencies
       - run: |
+          sudo apt-get -qq update
           sudo apt-get -qq install build-essential libffi-dev python-dev \
           libxml2-dev libxslt-dev xmlsec1 zlib1g-dev libjpeg-dev libwebp-dev
 

changelog.d/15672.bugfix

@@ -0,0 +1 @@
+Fix a bug introduced in Synapse v1.84.0 where workers do not start up when no `instance_map` was provided.

synapse/config/workers.py

@@ -222,7 +222,7 @@ def read_config(self, config: JsonDict, **kwargs: Any) -> None:
         # itself doesn't need this data as it would never have to talk to itself.
         instance_map: Dict[str, Any] = config.get("instance_map", {})
 
-        if instance_map and self.instance_name is not MAIN_PROCESS_INSTANCE_NAME:
+        if self.instance_name is not MAIN_PROCESS_INSTANCE_NAME:
             # The host used to connect to the main synapse
             main_host = config.get("worker_replication_host", None)
 

tests/app/test_homeserver_start.py

@@ -25,6 +25,8 @@ def test_wrong_start_caught(self) -> None:
         # Add a blank line as otherwise the next addition ends up on a line with a comment
         self.add_lines_to_config(["  "])
         self.add_lines_to_config(["worker_app: test_worker_app"])
+        self.add_lines_to_config(["worker_replication_host: 127.0.0.1"])
+        self.add_lines_to_config(["worker_replication_http_port: 0"])
 
         # Ensure that starting master process with worker config raises an exception
         with self.assertRaises(ConfigError):

tests/app/test_openid_listener.py

@@ -42,6 +42,7 @@ def default_config(self) -> JsonDict:
         # have to tell the FederationHandler not to try to access stuff that is only
         # in the primary store.
         conf["worker_app"] = "yes"
+        conf["instance_map"] = {"main": {"host": "127.0.0.1", "port": 0}}
 
         return conf
 

tests/config/test_workers.py

@@ -94,6 +94,7 @@ def test_old_configs_appservice_worker(self) -> None:
                 # so that it doesn't raise an exception here.
                 # (This is not read by `_should_this_worker_perform_duty`.)
                 "notify_appservices": False,
+                "instance_map": {"main": {"host": "127.0.0.1", "port": 0}},
             },
         )
 
@@ -138,7 +139,9 @@ def test_transitional_configs_master(self) -> None:
         """
 
         main_process_config = self._make_worker_config(
-            worker_app="synapse.app.homeserver", worker_name=None
+            worker_app="synapse.app.homeserver",
+            worker_name=None,
+            extras={"instance_map": {"main": {"host": "127.0.0.1", "port": 0}}},
         )
 
         self.assertTrue(
@@ -203,6 +206,7 @@ def test_transitional_configs_appservice_worker(self) -> None:
                 # so that it doesn't raise an exception here.
                 # (This is not read by `_should_this_worker_perform_duty`.)
                 "notify_appservices": False,
+                "instance_map": {"main": {"host": "127.0.0.1", "port": 0}},
             },
         )
 
@@ -236,7 +240,9 @@ def test_new_configs_master(self) -> None:
         Tests new config options. This is for the master's config.
         """
         main_process_config = self._make_worker_config(
-            worker_app="synapse.app.homeserver", worker_name=None
+            worker_app="synapse.app.homeserver",
+            worker_name=None,
+            extras={"instance_map": {"main": {"host": "127.0.0.1", "port": 0}}},
         )
 
         self.assertTrue(
@@ -262,7 +268,9 @@ def test_new_configs_appservice_worker(self) -> None:
         Tests new config options. This is for the worker's config.
         """
         appservice_worker_config = self._make_worker_config(
-            worker_app="synapse.app.generic_worker", worker_name="worker1"
+            worker_app="synapse.app.generic_worker",
+            worker_name="worker1",
+            extras={"instance_map": {"main": {"host": "127.0.0.1", "port": 0}}},
         )
 
         self.assertTrue(
@@ -298,6 +306,7 @@ def test_worker_duty_configs(self) -> None:
             extras={
                 "notify_appservices_from_worker": "worker2",
                 "update_user_directory_from_worker": "worker1",
+                "instance_map": {"main": {"host": "127.0.0.1", "port": 0}},
             },
         )
         self.assertFalse(worker1_config.should_notify_appservices)
@@ -309,6 +318,7 @@ def test_worker_duty_configs(self) -> None:
             extras={
                 "notify_appservices_from_worker": "worker2",
                 "update_user_directory_from_worker": "worker1",
+                "instance_map": {"main": {"host": "127.0.0.1", "port": 0}},
             },
         )
         self.assertTrue(worker2_config.should_notify_appservices)

tests/replication/test_federation_ack.py

@@ -32,6 +32,7 @@ def default_config(self) -> dict:
         config["worker_app"] = "synapse.app.generic_worker"
         config["worker_name"] = "federation_sender1"
         config["federation_sender_instances"] = ["federation_sender1"]
+        config["instance_map"] = {"main": {"host": "127.0.0.1", "port": 0}}
         return config
 
     def make_homeserver(self, reactor: MemoryReactor, clock: Clock) -> HomeServer:

tests/storage/test_rollback_worker.py

@@ -55,6 +55,7 @@ def default_config(self) -> JsonDict:
 
         # Mark this as a worker app.
         conf["worker_app"] = "yes"
+        conf["instance_map"] = {"main": {"host": "127.0.0.1", "port": 0}}
 
         return conf