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>

1 files changed, 5 insertions, 11 deletions

diff --git a/synapse/replication/http/_base.py b/synapse/replication/http/_base.py

index 23129962e9..dc7820f963 100644
--- a/synapse/replication/http/_base.py
+++ b/synapse/replication/http/_base.py
@@ -25,6 +25,7 @@ from twisted.internet.error import ConnectError, DNSLookupError
 from twisted.web.server import Request
 
 from synapse.api.errors import HttpResponseException, SynapseError
+from synapse.config.workers import MAIN_PROCESS_INSTANCE_NAME
 from synapse.http import RequestTimedOutError
 from synapse.http.server import HttpServer
 from synapse.http.servlet import parse_json_object_from_request
@@ -197,11 +198,6 @@ class ReplicationEndpoint(metaclass=abc.ABCMeta):
         client = hs.get_replication_client()
         local_instance_name = hs.get_instance_name()
 
-        # The value of these option should match the replication listener settings
-        master_host = hs.config.worker.worker_replication_host
-        master_port = hs.config.worker.worker_replication_http_port
-        master_tls = hs.config.worker.worker_replication_http_tls
-
         instance_map = hs.config.worker.instance_map
 
         outgoing_gauge = _pending_outgoing_requests.labels(cls.NAME)
@@ -213,7 +209,9 @@ class ReplicationEndpoint(metaclass=abc.ABCMeta):
             )
 
         @trace_with_opname("outgoing_replication_request")
-        async def send_request(*, instance_name: str = "master", **kwargs: Any) -> Any:
+        async def send_request(
+            *, instance_name: str = MAIN_PROCESS_INSTANCE_NAME, **kwargs: Any
+        ) -> Any:
             # We have to pull these out here to avoid circular dependencies...
             streams = hs.get_replication_command_handler().get_streams_to_replicate()
             replication = hs.get_replication_data_handler()
@@ -221,11 +219,7 @@ class ReplicationEndpoint(metaclass=abc.ABCMeta):
             with outgoing_gauge.track_inprogress():
                 if instance_name == local_instance_name:
                     raise Exception("Trying to send HTTP request to self")
-                if instance_name == "master":
-                    host = master_host
-                    port = master_port
-                    tls = master_tls
-                elif instance_name in instance_map:
+                if instance_name in instance_map:
                     host = instance_map[instance_name].host
                     port = instance_map[instance_name].port
                     tls = instance_map[instance_name].tls