Unix Sockets for HTTP Replication (#15708)

Unix socket support for `federation` and `client` Listeners has existed now for a little while(since [1.81.0](https://github.com/matrix-org/synapse/pull/15353)), but there was one last hold out before it could be complete: HTTP Replication communication. This should finish it up. The Listeners would have always worked, but would have had no way to be talked to/at.

---------

Co-authored-by: Eric Eastwood <madlittlemods@gmail.com>
Co-authored-by: Olivier Wilkinson (reivilibre) <oliverw@matrix.org>
Co-authored-by: Eric Eastwood <erice@element.io>

1 files changed, 22 insertions, 2 deletions

diff --git a/synapse/config/workers.py b/synapse/config/workers.py
index ccfe75eaf3..e55ca12a36 100644
--- a/synapse/config/workers.py
+++ b/synapse/config/workers.py
@@ -94,7 +94,7 @@ class ConfigModel(BaseModel):
         allow_mutation = False
 
 
-class InstanceLocationConfig(ConfigModel):
+class InstanceTcpLocationConfig(ConfigModel):
     """The host and port to talk to an instance via HTTP replication."""
 
     host: StrictStr
@@ -110,6 +110,23 @@ class InstanceLocationConfig(ConfigModel):
         return f"{self.host}:{self.port}"
 
 
+class InstanceUnixLocationConfig(ConfigModel):
+    """The socket file to talk to an instance via HTTP replication."""
+
+    path: StrictStr
+
+    def scheme(self) -> str:
+        """Hardcode a retrievable scheme"""
+        return "unix"
+
+    def netloc(self) -> str:
+        """Nicely format the address location data"""
+        return f"{self.path}"
+
+
+InstanceLocationConfig = Union[InstanceTcpLocationConfig, InstanceUnixLocationConfig]
+
+
 @attr.s
 class WriterLocations:
     """Specifies the instances that write various streams.
@@ -270,9 +287,12 @@ class WorkerConfig(Config):
                     % MAIN_PROCESS_INSTANCE_MAP_NAME
                 )
 
+        # type-ignore: the expression `Union[A, B]` is not a Type[Union[A, B]] currently
         self.instance_map: Dict[
             str, InstanceLocationConfig
-        ] = parse_and_validate_mapping(instance_map, InstanceLocationConfig)
+        ] = parse_and_validate_mapping(
+            instance_map, InstanceLocationConfig  # type: ignore[arg-type]
+        )
 
         # Map from type of streams to source, c.f. WriterLocations.
         writers = config.get("stream_writers") or {}