Return PFS broadcast room id in info response

This is necessary after
- raiden-network/raiden-service-bundle#187
- raiden-network/raiden#6442

With those PRs the set of federation servers can become disjunct between
different Raiden client versions. Therefore we can't rely on the
previous check in the Raiden client if the PFS' server is in the known
servers set.

The RoomID is uniquely identifying a specific broadcasting room and can
therefore be used as a better information source for this check.

Author: ulope

pyproject.toml

@@ -0,0 +1,14 @@
+[tool.black]
+line-length = 99
+target-version = ['py37']
+include = '\.pyi?$'
+exclude = '''
+/(
+    \.git
+  | \.mypy_cache
+  | \.tox
+  | \.venv
+  | build
+  | dist
+)/
+'''

src/pathfinding_service/api.py

@@ -417,6 +417,7 @@ def get(self) -> Tuple[dict, int]:
             "payment_address": to_checksum_address(self.pathfinding_service.address),
             "UTC": datetime.utcnow().isoformat(),
             "matrix_server": self.api.pathfinding_service.matrix_listener.base_url,
+            "matrix_room_id": self.api.pathfinding_service.matrix_listener.broadcast_room_id,
         }
         return info, 200
 
@@ -445,7 +446,10 @@ def get(self, token_network_address: str) -> Tuple[List[Dict[str, Any]], int]:
 
 class DebugPathResource(PathfinderResource):
     def get(  # pylint: disable=no-self-use
-        self, token_network_address: str, source_address: str, target_address: Optional[str] = None
+        self,
+        token_network_address: str,
+        source_address: str,
+        target_address: Optional[str] = None,
     ) -> Tuple[dict, int]:
         request_count = 0
         responses = []

src/raiden_libs/matrix.py

@@ -41,7 +41,7 @@
 from raiden.storage.serialization.serializer import MessageSerializer
 from raiden.utils.cli import get_matrix_servers
 from raiden.utils.signer import LocalSigner
-from raiden.utils.typing import Address, ChainID
+from raiden.utils.typing import Address, ChainID, RoomID
 from raiden_contracts.utils.type_aliases import PrivateKey
 
 log = structlog.get_logger(__name__)
@@ -162,6 +162,7 @@ def __init__(
             http_retry_timeout=40,
             http_retry_delay=matrix_http_retry_delay,
         )
+        self.broadcast_room_id: Optional[RoomID] = None
         self._broadcast_room: Optional[Room] = None
         self._displayname_cache = DisplayNameCache()
         self.base_url = self._client.api.base_url
@@ -205,10 +206,7 @@ def _start_client(self) -> None:
         try:
             self.user_manager.start()
 
-            login(
-                self._client,
-                signer=LocalSigner(private_key=self.private_key),
-            )
+            login(self._client, signer=LocalSigner(private_key=self.private_key))
         except (MatrixRequestError, ValueError):
             raise ConnectionError("Could not login/register to matrix.")
 
@@ -219,6 +217,7 @@ def _start_client(self) -> None:
             self._broadcast_room = join_broadcast_room(
                 client=self._client, broadcast_room_alias=room_alias
             )
+            self.broadcast_room_id = self._broadcast_room.room_id
 
             sync_filter_id = self._client.create_sync_filter(rooms=[self._broadcast_room])
             self._client.set_sync_filter_id(sync_filter_id)
@@ -231,8 +230,7 @@ def follow_address_presence(self, address: Address, refresh: bool = False) -> No
         if refresh:
             self.user_manager.populate_userids_for_address(address)
             self.user_manager.track_address_presence(
-                address=address,
-                user_ids=self.user_manager.get_userids_for_address(address),
+                address=address, user_ids=self.user_manager.get_userids_for_address(address)
             )
 
         log.debug(