Make start_driver require a Driver object

src/py/flwr/server/compat/app.py

@@ -15,50 +15,35 @@
 """Flower driver app."""
 
 
-import sys
 from logging import INFO
-from pathlib import Path
-from typing import Optional, Union
+from typing import Optional
 
 from flwr.common import EventType, event
-from flwr.common.address import parse_address
-from flwr.common.logger import log, warn_deprecated_feature
+from flwr.common.logger import log
 from flwr.server.client_manager import ClientManager
 from flwr.server.history import History
 from flwr.server.server import Server, init_defaults, run_fl
 from flwr.server.server_config import ServerConfig
 from flwr.server.strategy import Strategy
 
-from ..driver import Driver, GrpcDriver
+from ..driver import Driver
 from .app_utils import start_update_client_manager_thread
 
-DEFAULT_SERVER_ADDRESS_DRIVER = "[::]:9091"
-
-ERROR_MESSAGE_DRIVER_NOT_CONNECTED = """
-[Driver] Error: Not connected.
-
-Call `connect()` on the `Driver` instance before calling any of the other `Driver`
-methods.
-"""
-
 
 def start_driver(  # pylint: disable=too-many-arguments, too-many-locals
     *,
-    server_address: str = DEFAULT_SERVER_ADDRESS_DRIVER,
+    driver: Driver,
     server: Optional[Server] = None,
     config: Optional[ServerConfig] = None,
     strategy: Optional[Strategy] = None,
     client_manager: Optional[ClientManager] = None,
-    root_certificates: Optional[Union[bytes, str]] = None,
-    driver: Optional[Driver] = None,
 ) -> History:
     """Start a Flower Driver API server.
 
     Parameters
     ----------
-    server_address : Optional[str]
-        The IPv4 or IPv6 address of the Driver API server.
-        Defaults to `"[::]:8080"`.
+    driver : Driver
+        The Driver object to use.
     server : Optional[flwr.server.Server] (default: None)
         A server implementation, either `flwr.server.Server` or a subclass
         thereof. If no instance is provided, then `start_driver` will create
@@ -74,50 +59,14 @@ def start_driver(  # pylint: disable=too-many-arguments, too-many-locals
         An implementation of the class `flwr.server.ClientManager`. If no
         implementation is provided, then `start_driver` will use
         `flwr.server.SimpleClientManager`.
-    root_certificates : Optional[Union[bytes, str]] (default: None)
-        The PEM-encoded root certificates as a byte string or a path string.
-        If provided, a secure connection using the certificates will be
-        established to an SSL-enabled Flower server.
-    driver : Optional[Driver] (default: None)
-        The Driver object to use.
 
     Returns
     -------
     hist : flwr.server.history.History
         Object containing training and evaluation metrics.
-
-    Examples
-    --------
-    Starting a driver that connects to an insecure server:
-
-    >>> start_driver()
-
-    Starting a driver that connects to an SSL-enabled server:
-
-    >>> start_driver(
-    >>>     root_certificates=Path("/crts/root.pem").read_bytes()
-    >>> )
     """
     event(EventType.START_DRIVER_ENTER)
 
-    if driver is None:
-        # Not passing a `Driver` object is deprecated
-        warn_deprecated_feature("start_driver")
-
-        # Parse IP address
-        parsed_address = parse_address(server_address)
-        if not parsed_address:
-            sys.exit(f"Server IP address ({server_address}) cannot be parsed.")
-        host, port, is_v6 = parsed_address
-        address = f"[{host}]:{port}" if is_v6 else f"{host}:{port}"
-
-        # Create the Driver
-        if isinstance(root_certificates, str):
-            root_certificates = Path(root_certificates).read_bytes()
-        driver = GrpcDriver(
-            driver_service_address=address, root_certificates=root_certificates
-        )
-
     # Initialize the Driver API server and config
     initialized_server, initialized_config = init_defaults(
         server=server,