How to stop a Central System properly

[Logn99]

Hello together
I am currently trying to implement an Ocpp Central System in Python. I was already able to connect and communicate with an wallbox using the library.

However, I have the problem that I do not know how to shut down the server properly. Does anyone have an example?

I am dealing with websockets in python for the first time and can't find a way that works with the ocpp library. Additionally it should work on windows as well.

[Logn99]

I am not sure how to share the code. That's why I just copied it in now

import logging
import websockets
import asyncio
import threading

from MyChargePoint import MyChargePoint


class Server(threading.Thread):
    def __init__(self,serverAddress,port):
        threading.Thread.__init__(self)
        self.ws = None
        self.clients = []
        self._stop_event = threading.Event()
        self.server_address = serverAddress
        self.port = port

    def stop(self):
        if len(self.clients) != 0:
            # testcase with one client --> [0]
            client = self.clients[0]
            client.isRunning = False
            self.clients.remove(client)
        self.ws.close()
        
    def run(self):
        asyncio.run(self.init_ws())

    # init websocket
    async def init_ws(self):
        self.ws = await websockets.serve(
            self.on_connect,self.server_address, self.port, subprotocols=["ocpp1.6"])
        logging.info("Server Started listening to new connections...")
        await  self.ws.wait_closed()
        
    # handle connect requests

    
    async def on_connect(self,websocket,path):
        try:
            requested_protocols = websocket.request_headers["Sec-WebSocket-Protocol"]
        except KeyError:
            logging.error("Client hasn't requested any Subprotocol. Closing Connection")
            return await websocket.close()
        if websocket.subprotocol:
            logging.info("Protocols Matched: %s", websocket.subprotocol)
        else:
            # In the websockets lib if no subprotocols are supported by the
            # client and the server, it proceeds without a subprotocol,
            # so we have to manually close the connection.
            logging.warning(
                "Protocols Mismatched | Expected Subprotocols: %s,"
                " but client supports  %s | Closing connection",
                websocket.available_subprotocols,
                requested_protocols,
            )
            return await websocket.close()

        charge_point_id = path.strip("/")
        logging.info("connected to Wallbox: %s",charge_point_id)
        cp = MyChargePoint(charge_point_id, websocket)
        self.clients.append(cp)
        
        await cp.start()

    # functions to send msg. to the client
    def send_message(self,id,command):
        asyncio.run(self.clients[0].setChargingProfil())

[OrangeTux]

The code snippet suggests that you're using the ocpp library in a mutltithreaded environment. I would discourage that. Some internals of the ocpp library are not threadsafe. See also my comment here: #472 (comment).

[OrangeTux]

I think the websockets FAQ addresses your question.