Add `instance_map` config and route replication calls (#7495)

1 files changed, 15 insertions, 6 deletions

diff --git a/synapse/replication/http/_base.py b/synapse/replication/http/_base.py
index f88c80ae84..c3136a4eb9 100644
--- a/synapse/replication/http/_base.py
+++ b/synapse/replication/http/_base.py
@@ -141,17 +141,26 @@ class ReplicationEndpoint(object):
         Returns a callable that accepts the same parameters as `_serialize_payload`.
         """
         clock = hs.get_clock()
-        host = hs.config.worker_replication_host
-        port = hs.config.worker_replication_http_port
-
         client = hs.get_simple_http_client()
 
+        master_host = hs.config.worker_replication_host
+        master_port = hs.config.worker_replication_http_port
+
+        instance_map = hs.config.worker.instance_map
+
         @trace(opname="outgoing_replication_request")
         @defer.inlineCallbacks
         def send_request(instance_name="master", **kwargs):
-            # Currently we only support sending requests to master process.
-            if instance_name != "master":
-                raise Exception("Unknown instance")
+            if instance_name == "master":
+                host = master_host
+                port = master_port
+            elif instance_name in instance_map:
+                host = instance_map[instance_name].host
+                port = instance_map[instance_name].port
+            else:
+                raise Exception(
+                    "Instance %r not in 'instance_map' config" % (instance_name,)
+                )
 
             data = yield cls._serialize_payload(**kwargs)