add before_connect and endpoint_args to websocket exchange

octobot_trading/exchanges/types/websocket_exchange.pxd

@@ -31,6 +31,8 @@ cdef class WebsocketExchange:
     cdef bint use_testnet
     cdef bint is_authenticated
 
+    cdef public dict endpoint_args
+
     cdef public list currencies
     cdef public list pairs
     cdef public list time_frames

octobot_trading/exchanges/types/websocket_exchange.py

@@ -70,6 +70,9 @@ def __init__(self,
         self.is_authenticated = False
         self.should_stop = False
 
+        # keyword arguments to be given to get_ws_endpoint
+        self.endpoint_args = {}
+
         self.currencies = currencies if currencies else []
         self.pairs = []
         self.channels = []
@@ -112,9 +115,12 @@ async def _connect(self):
             # manage max delay
             if delay >= self.MAX_DELAY:
                 delay = self.MAX_DELAY
-
             try:
-                async with websockets.connect(self.get_ws_endpoint()
+                await self.before_connect()
+            except Exception as e:
+                self.logger.exception(e, True, f"Error on before_connect {e}")
+            try:
+                async with websockets.connect(self.get_ws_endpoint(**self.endpoint_args)
                                               if not self.use_testnet else self.get_ws_testnet_endpoint(),
                                               subprotocols=self.get_sub_protocol()) as websocket:
                     self.websocket = websocket
@@ -202,6 +208,9 @@ def close(self):
         self.websocket.close()
         self.on_close()
 
+    async def before_connect(self):
+        pass
+
     async def prepare(self):
         pass