websocket_server.py

import sys, os
import pathlib
import websockets, asyncio, ssl

import logging
logger = logging.getLogger('websockets')
logger.setLevel(logging.INFO)
logger.addHandler(logging.StreamHandler())

async def handler(ws, path):
  try:
    while True:
      data = await ws.recv()
      print(f"WS Server ({ws.path}) sent '{data}'")
      await ws.send(data)
  except websockets.exceptions.ConnectionClosedOK as e:
    print("Client closed", e)
  except Exception as e:
    print("Exception:", e)

if __name__ == "__main__":
  # create ssl context for websocket secure
  ssl_context = None
  if len(sys.argv) == 2 and sys.argv[1].lower() == "secure":
    normalize_path = lambda path: path.replace("\\", "/").replace("/", os.path.sep)
    ssl_file_path = normalize_path(os.path.join(pathlib.Path(__file__).resolve().parent.parent, "preferences/local.pem"))
    ssl_context = ssl.SSLContext(ssl.PROTOCOL_TLS_SERVER)
    ssl_context.load_cert_chain(ssl_file_path)
  # start websocket server
  ws_server = websockets.serve(handler, "127.0.0.1", 1609, ssl=ssl_context)
  asyncio.get_event_loop().run_until_complete(ws_server)
  asyncio.get_event_loop().run_forever()