Merge remote-tracking branch 'origin/release-v1.15.1' into bbz/info-mainline-1.15

1 files changed, 44 insertions, 1 deletions

diff --git a/synapse/config/workers.py b/synapse/config/workers.py

index fef72ed974..ed06b91a54 100644
--- a/synapse/config/workers.py
+++ b/synapse/config/workers.py
@@ -13,7 +13,29 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from ._base import Config
+import attr
+
+from ._base import Config, ConfigError
+
+
+@attr.s
+class InstanceLocationConfig:
+    """The host and port to talk to an instance via HTTP replication.
+    """
+
+    host = attr.ib(type=str)
+    port = attr.ib(type=int)
+
+
+@attr.s
+class WriterLocations:
+    """Specifies the instances that write various streams.
+
+    Attributes:
+        events: The instance that writes to the event and backfill streams.
+    """
+
+    events = attr.ib(default="master", type=str)
 
 
 class WorkerConfig(Config):
@@ -71,6 +93,27 @@ class WorkerConfig(Config):
                 elif not bind_addresses:
                     bind_addresses.append("")
 
+        # A map from instance name to host/port of their HTTP replication endpoint.
+        instance_map = config.get("instance_map") or {}
+        self.instance_map = {
+            name: InstanceLocationConfig(**c) for name, c in instance_map.items()
+        }
+
+        # Map from type of streams to source, c.f. WriterLocations.
+        writers = config.get("stream_writers") or {}
+        self.writers = WriterLocations(**writers)
+
+        # Check that the configured writer for events also appears in
+        # `instance_map`.
+        if (
+            self.writers.events != "master"
+            and self.writers.events not in self.instance_map
+        ):
+            raise ConfigError(
+                "Instance %r is configured to write events but does not appear in `instance_map` config."
+                % (self.writers.events,)
+            )
+
     def read_arguments(self, args):
         # We support a bunch of command line arguments that override options in
         # the config. A lot of these options have a worker_* prefix when running