Improve websocket connection

This commit will improve the websocket to use gevent + gevent-websocket to avoid
the error KeyError: 'Session is disconnected'
Fix kytos#416

etc/kytos/logging.ini

@@ -5,7 +5,7 @@ keys: console,syslog
 keys: console,syslog
 
 [loggers]
-keys: root,api_server,socket
+keys: root,api_server
 
 [formatter_syslog]
 format: %(name)s:%(levelname)s %(module)s:%(lineno)d:  %(message)s
@@ -29,10 +29,5 @@ handlers: syslog,console
 
 [logger_api_server]
 level: INFO
-qualname: werkzeug
-handlers:
-
-[logger_socket]
-level: ERROR
-qualname: engineio
+qualname: geventwebsocket.handler
 handlers:

kytos/core/api_server.py

@@ -26,7 +26,7 @@ def __init__(self, app_name, debug=False):
         self.set_debug(debug)
 
         self.app = Flask(app_name, root_path=self.flask_dir)
-        self.server = SocketIO(self.app, async_mode='threading')
+        self.server = SocketIO(self.app)
 
     def set_debug(self, debug):
         """Method used to set debug mode.

kytos/core/websocket.py

@@ -43,7 +43,7 @@ def update_buffer(self):
         self.stream.truncate(0)
 
         if len(self.buff) >= self.buffer_max_size:
-            new_size = self.buffer_max_size/2
+            new_size = int(self.buffer_max_size/2)
             self.buff = self.buff[new_size:]
 
     def handle_messages(self, json):

requirements.txt

@@ -9,3 +9,5 @@ python-daemon>=2.1.2
 # Maybe we need to remove this on the future
 setuptools>=34.0.0
 jinja2
+gevent-websocket
+gevent