Add `sharding_allowed` to the WorkerTemplate rather than having a separate function for that

docker/configure_workers_and_start.py

@@ -90,6 +90,9 @@ class WorkerTemplate:
     shared_extra_conf: Callable[[str], Dict[str, Any]] = lambda _worker_name: {}
     worker_extra_conf: str = ""
 
+    # True if and only if multiple of this worker type are allowed.
+    sharding_allowed: bool = True
+
 
 # Workers with exposed endpoints needs either "client", "federation", or "media" listener_resources
 # Watching /_matrix/client needs a "client" listener
@@ -218,6 +221,7 @@ WORKERS_CONFIG: Dict[str, WorkerTemplate] = {
         # This worker cannot be sharded. Therefore, there should only ever be one
         # background worker. This is enforced for the safety of your database.
         shared_extra_conf=lambda worker_name: {"run_background_tasks_on": worker_name},
+        sharding_allowed=False,
     ),
     "event_creator": WorkerTemplate(
         listener_resources={"client"},
@@ -243,6 +247,7 @@ WORKERS_CONFIG: Dict[str, WorkerTemplate] = {
         shared_extra_conf=lambda worker_name: {
             "stream_writers": {"account_data": [worker_name]}
         },
+        sharding_allowed=False,
     ),
     "presence": WorkerTemplate(
         listener_resources={"client", "replication"},
@@ -250,6 +255,7 @@ WORKERS_CONFIG: Dict[str, WorkerTemplate] = {
         shared_extra_conf=lambda worker_name: {
             "stream_writers": {"presence": [worker_name]}
         },
+        sharding_allowed=False,
     ),
     "receipts": WorkerTemplate(
         listener_resources={"client", "replication"},
@@ -260,6 +266,7 @@ WORKERS_CONFIG: Dict[str, WorkerTemplate] = {
         shared_extra_conf=lambda worker_name: {
             "stream_writers": {"receipts": [worker_name]}
         },
+        sharding_allowed=False,
     ),
     "to_device": WorkerTemplate(
         listener_resources={"client", "replication"},
@@ -267,6 +274,7 @@ WORKERS_CONFIG: Dict[str, WorkerTemplate] = {
         shared_extra_conf=lambda worker_name: {
             "stream_writers": {"to_device": [worker_name]}
         },
+        sharding_allowed=False,
     ),
     "typing": WorkerTemplate(
         listener_resources={"client", "replication"},
@@ -274,6 +282,7 @@ WORKERS_CONFIG: Dict[str, WorkerTemplate] = {
         shared_extra_conf=lambda worker_name: {
             "stream_writers": {"typing": [worker_name]}
         },
+        sharding_allowed=False,
     ),
 }
 
@@ -495,23 +504,6 @@ def apply_requested_multiplier_for_worker(worker_types: List[str]) -> List[str]:
     return new_worker_types
 
 
-def is_sharding_allowed_for_worker_type(worker_type: str) -> bool:
-    """Helper to check to make sure worker types that cannot have multiples do not.
-
-    Args:
-        worker_type: The type of worker to check against.
-    Returns: True if allowed, False if not
-    """
-    return worker_type not in [
-        "background_worker",
-        "account_data",
-        "presence",
-        "receipts",
-        "typing",
-        "to_device",
-    ]
-
-
 def split_and_strip_string(
     given_string: str, split_char: str, max_split: SupportsIndex = -1
 ) -> List[str]:
@@ -637,7 +629,7 @@ def parse_worker_types(
                 )
 
             if worker_type in worker_type_shard_counter:
-                if not is_sharding_allowed_for_worker_type(worker_type):
+                if not WORKERS_CONFIG[worker_type].sharding_allowed:
                     error(
                         f"There can be only a single worker with {worker_type} "
                         "type. Please recount and remove."