feat(framework) Allow flower-server-app to start with run_id

src/py/flwr/server/run_serverapp.py

@@ -22,6 +22,7 @@
 from typing import Optional
 
 from flwr.common import Context, EventType, RecordSet, event
+from flwr.common.config import get_flwr_dir, get_project_config, get_project_dir
 from flwr.common.logger import log, update_console_handler, warn_deprecated_feature
 from flwr.common.object_ref import load_app
 from flwr.proto.driver_pb2 import CreateRunRequest # pylint: disable=E0611
@@ -43,7 +44,7 @@ def run(
  if not (server_app_attr is None) ^ (loaded_server_app is None):
  raise ValueError(
  "Either `server_app_attr` or `loaded_server_app` should be set "
- "but not both. "
+ "but not both."
  )
 
  if server_app_dir is not None:
@@ -76,7 +77,7 @@ def _load() -> ServerApp:
  log(DEBUG, "ServerApp finished running.")
 
 
-def run_server_app() -> None:
+def run_server_app() -> None: # pylint: disable=too-many-branches
  """Run Flower server app."""
  event(EventType.RUN_SERVER_APP_ENTER)
 
@@ -136,32 +137,50 @@ def run_server_app() -> None:
  cert_path,
  )
 
- log(
- DEBUG,
- "Flower will load ServerApp `%s`",
- getattr(args, "server-app"),
+ if not (getattr(args, "server-app") is None) ^ (args.run_id is None):
+ raise sys.exit(
+ "Invalid options: Either `server-app` or `--run-id` "
+ "should be set but not both."
+ )
+
+ stub = GrpcDriverStub(
+ driver_service_address=args.superlink, root_certificates=root_certificates
  )
+ # Create run if run_id is not provided
+ if args.run_id is None:
+ stub.connect()
+ req = CreateRunRequest(fab_id=args.fab_id, fab_version=args.fab_version)
+ res = stub.create_run(req)
+ run_id = res.run_id
+ else:
+ run_id = args.run_id
+
+ # Initialize GrpcDriver
+ driver = GrpcDriver(run_id=run_id, stub=stub)
+
+ # Dynamically obtain ServerApp path based on run_id
+ if args.run_id is not None:
+ if args.flwr_dir is None:
+ flwr_dir = get_flwr_dir()
+ else:
+ flwr_dir = Path(args.flwr_dir).absolute()
+ server_app_dir = str(
+ get_project_dir(driver.run.fab_id, driver.run.fab_version, flwr_dir)
+ )
+ config = get_project_config(server_app_dir)
+ server_app_attr = config["flower"]["components"]["serverapp"]
+ else:
+ server_app_dir = str(Path(args.dir).absolute())
+ server_app_attr = getattr(args, "server-app")
+
+ log(DEBUG, "Flower will load ServerApp `%s` in %s", server_app_attr, server_app_dir)
 
  log(
  DEBUG,
  "root_certificates: `%s`",
  root_certificates,
  )
 
- server_app_dir = args.dir
- server_app_attr = getattr(args, "server-app")
-
- # Create run
- stub = GrpcDriverStub(
- driver_service_address=args.superlink, root_certificates=root_certificates
- )
- stub.connect()
- req = CreateRunRequest(fab_id=args.fab_id, fab_version=args.fab_version)
- res = stub.create_run(req)
-
- # Initialize GrpcDriver
- driver = GrpcDriver(run_id=res.run_id, stub=stub)
-
  # Run the ServerApp with the Driver
  run(driver=driver, server_app_dir=server_app_dir, server_app_attr=server_app_attr)
 
@@ -179,6 +198,8 @@ def _parse_args_run_server_app() -> argparse.ArgumentParser:
 
  parser.add_argument(
  "server-app",
+ nargs="?",
+ default=None,
  help="For example: `server:app` or `project.package.module:wrapper.app`",
  )
  parser.add_argument(
@@ -228,5 +249,22 @@ def _parse_args_run_server_app() -> argparse.ArgumentParser:
  type=str,
  help="The version of the FAB used in the run.",
  )
+ parser.add_argument(
+ "--run-id",
+ default=None,
+ type=int,
+ help="The identifier of the run.",
+ )
+ parser.add_argument(
+ "--flwr-dir",
+ default=None,
+ help="""The path containing installed Flower Apps.
+ By default, this value is equal to:
+
+ - `$FLWR_HOME/` if `$FLWR_HOME` is defined
+ - `$XDG_DATA_HOME/.flwr/` if `$XDG_DATA_HOME` is defined
+ - `$HOME/.flwr/` in all other cases
+ """,
+ )
 
  return parser