catch exception on socketio connection (#1365)

* catch exception on sockteio connection

Author: sanderegg

services/web/server/src/simcore_service_webserver/socketio/handlers.py

@@ -11,21 +11,23 @@
 from typing import Dict, List, Optional
 
 from aiohttp import web
-from socketio.exceptions import ConnectionRefusedError as socket_io_connection_error
 
 from servicelib.observer import observe
 from servicelib.utils import fire_and_forget_task, logged_gather
+from socketio.exceptions import ConnectionRefusedError as SocketIOConnectionError
 
 from ..login.decorators import RQT_USERID_KEY, login_required
 from ..resource_manager.websocket_manager import managed_resource
 from .config import get_socket_server
+from .handlers_utils import register_socketio_handler
 
 ANONYMOUS_USER_ID = -1
 _SOCKET_IO_AIOHTTP_REQUEST_KEY = "aiohttp.request"
 
 log = logging.getLogger(__file__)
 
 
+@register_socketio_handler
 async def connect(sid: str, environ: Dict, app: web.Application) -> bool:
     """socketio reserved handler for when the fontend connects through socket.io
 
@@ -42,7 +44,9 @@ async def connect(sid: str, environ: Dict, app: web.Application) -> bool:
     try:
         await authenticate_user(sid, app, request)
     except web.HTTPUnauthorized:
-        raise socket_io_connection_error("authentification failed")
+        raise SocketIOConnectionError("authentification failed")
+    except Exception as exc:  # pylint: disable=broad-except
+        raise SocketIOConnectionError(f"Unexpected error: {exc}")
 
     return True
 
@@ -107,6 +111,7 @@ async def user_logged_out(
             fire_and_forget_task(disconnect_other_sockets(sio, sockets))
 
 
+@register_socketio_handler
 async def disconnect(sid: str, app: web.Application) -> None:
     """socketio reserved handler for when the socket.io connection is disconnected.
 

services/web/server/src/simcore_service_webserver/socketio/handlers_utils.py

@@ -7,6 +7,9 @@
 from .config import APP_CLIENT_SOCKET_DECORATED_HANDLERS_KEY, get_socket_server
 
 
+socketio_handlers_registry = []
+
+
 def socket_io_handler(app: web.Application):
     """this decorator allows passing additional paramters to python-socketio compatible handlers.
     I.e. python-socketio handler expect functions of type `async def function(sid, *args, **kwargs)`
@@ -18,6 +21,7 @@ def decorator(func):
         async def wrapped(*args, **kwargs):
             return await func(*args, **kwargs, app=app)
 
+
         return wrapped
 
     return decorator
@@ -33,18 +37,34 @@ def has_socket_io_handler_signature(fun) -> bool:
 
 def register_handlers(app: web.Application, module: ModuleType):
     sio = get_socket_server(app)
-    predicate = (
-        lambda obj: inspect.isfunction(obj)
-        and has_socket_io_handler_signature(obj)
-        and inspect.iscoroutinefunction(obj)
-        and inspect.getmodule(obj) == module
-    )
-    member_fcts = inspect.getmembers(module, predicate)
+    member_fcts = [
+        fct for fct in socketio_handlers_registry if inspect.getmodule(fct) == module
+    ]
     # convert handler
     partial_fcts = [
-        socket_io_handler(app)(func_handler) for _, func_handler in member_fcts
+        socket_io_handler(app)(func_handler) for func_handler in member_fcts
     ]
     app[APP_CLIENT_SOCKET_DECORATED_HANDLERS_KEY] = partial_fcts
     # register the fcts
     for func in partial_fcts:
         sio.on(func.__name__, handler=func)
+
+
+def register_socketio_handler(func: callable) -> callable:
+    """this decorator appends handlers to a registry if they fit certain rules
+
+    :param func: the function to call
+    :type func: callable
+    :return: the function to call
+    :rtype: callable
+    """
+    is_handler = (
+        inspect.isfunction(func)
+        and has_socket_io_handler_signature(func)
+        and inspect.iscoroutinefunction(func)
+    )
+    if is_handler:
+        socketio_handlers_registry.append(func)
+    else:
+        raise SyntaxError("the function shall be of type fct(*args, app: web.Application")
+    return func