Remove `worker_replication_*` settings (#15491)

* Add master to the instance_map as part of Complement, have ReplicationEndpoint look at instance_map for master.

* Fix typo in drive by.

* Remove unnecessary worker_replication_* bits from unit tests and add master to instance_map(hopefully in the right place)

* Several updates:

1. Switch from master to main for naming the main process in the instance_map. Add useful constants for easier adjustment of names in the future.
2. Add backwards compatibility for worker_replication_* to allow time to transition to new style. Make sure to prioritize declaring main directly on the instance_map.
3. Clean up old comments/commented out code.
4. Adjust unit tests to match with new code.
5. Adjust Complement setup infrastructure to only add main to the instance_map if workers are used and remove now unused options from the worker.yaml template.

* Initial Docs upload

* Changelog

* Missed some commented out code that can go now

* Remove TODO comment that no longer holds true.

* Fix links in docs

* More docs

* Remove debug logging

* Apply suggestions from code review

Co-authored-by: reivilibre <olivier@librepush.net>

* Apply suggestions from code review

Co-authored-by: reivilibre <olivier@librepush.net>

* Update version to latest, include completeish before/after examples in upgrade notes.

* Fix up and docs too

---------

Co-authored-by: reivilibre <olivier@librepush.net>

4 files changed, 4 insertions, 10 deletions

diff --git a/tests/replication/_base.py b/tests/replication/_base.py
index 0f1a8a145f..eb9b1f1cd9 100644
--- a/tests/replication/_base.py
+++ b/tests/replication/_base.py
@@ -110,8 +110,7 @@ class BaseStreamTestCase(unittest.HomeserverTestCase):
     def _get_worker_hs_config(self) -> dict:
         config = self.default_config()
         config["worker_app"] = "synapse.app.generic_worker"
-        config["worker_replication_host"] = "testserv"
-        config["worker_replication_http_port"] = "8765"
+        config["instance_map"] = {"main": {"host": "testserv", "port": 8765}}
         return config
 
     def _build_replication_data_handler(self) -> "TestReplicationDataHandler":
@@ -249,6 +248,7 @@ class BaseMultiWorkerStreamTestCase(unittest.HomeserverTestCase):
         """
         base = super().default_config()
         base["redis"] = {"enabled": True}
+        base["instance_map"] = {"main": {"host": "testserv", "port": 8765}}
         return base
 
     def setUp(self) -> None:
@@ -310,7 +310,7 @@ class BaseMultiWorkerStreamTestCase(unittest.HomeserverTestCase):
     def make_worker_hs(
         self, worker_app: str, extra_config: Optional[dict] = None, **kwargs: Any
     ) -> HomeServer:
-        """Make a new worker HS instance, correctly connecting replcation
+        """Make a new worker HS instance, correctly connecting replication
         stream to the master HS.
 
         Args:
@@ -388,8 +388,6 @@ class BaseMultiWorkerStreamTestCase(unittest.HomeserverTestCase):
 
     def _get_worker_hs_config(self) -> dict:
         config = self.default_config()
-        config["worker_replication_host"] = "testserv"
-        config["worker_replication_http_port"] = "8765"
         return config
 
     def replicate(self) -> None:
diff --git a/tests/replication/test_auth.py b/tests/replication/test_auth.py
index 98602371e4..f7bca0063d 100644
--- a/tests/replication/test_auth.py
+++ b/tests/replication/test_auth.py
@@ -43,9 +43,6 @@ class WorkerAuthenticationTestCase(BaseMultiWorkerStreamTestCase):
     def _get_worker_hs_config(self) -> dict:
         config = self.default_config()
         config["worker_app"] = "synapse.app.generic_worker"
-        config["worker_replication_host"] = "testserv"
-        config["worker_replication_http_port"] = "8765"
-
         return config
 
     def _test_register(self) -> FakeChannel:
diff --git a/tests/replication/test_client_reader_shard.py b/tests/replication/test_client_reader_shard.py
index eca5033761..a18859099f 100644
--- a/tests/replication/test_client_reader_shard.py
+++ b/tests/replication/test_client_reader_shard.py
@@ -29,8 +29,6 @@ class ClientReaderTestCase(BaseMultiWorkerStreamTestCase):
     def _get_worker_hs_config(self) -> dict:
         config = self.default_config()
         config["worker_app"] = "synapse.app.generic_worker"
-        config["worker_replication_host"] = "testserv"
-        config["worker_replication_http_port"] = "8765"
         return config
 
     def test_register_single_worker(self) -> None:
diff --git a/tests/replication/test_sharded_event_persister.py b/tests/replication/test_sharded_event_persister.py
index 7f9cc67e73..4623d737fb 100644
--- a/tests/replication/test_sharded_event_persister.py
+++ b/tests/replication/test_sharded_event_persister.py
@@ -50,6 +50,7 @@ class EventPersisterShardTestCase(BaseMultiWorkerStreamTestCase):
         conf = super().default_config()
         conf["stream_writers"] = {"events": ["worker1", "worker2"]}
         conf["instance_map"] = {
+            "main": {"host": "testserv", "port": 8765},
             "worker1": {"host": "testserv", "port": 1001},
             "worker2": {"host": "testserv", "port": 1002},
         }