如何在pythonwebsocket服务器握手响应中设置“secwebsocketprotocol”头？

Question

我有一个pythonwebsocket服务器和一个nodejs客户端，但我无法实现websocket的协议握手。

下面的最小WebSocket服务器使用Flask-Socket（使用gevent-webSocket）。文件名为ws_server.py：

#!/usr/bin/python3
# -*- coding: utf-8 -*-
from flask import Flask, request, Response
from flask_sockets import Sockets

app = Flask(__name__)
sockets = Sockets(app)

@sockets.route('/')
def echo_socket(ws):
    # print("type request: ",type(request))
    # print("dir  request: ", dir(request))
    print("request.headers: ", request.headers)
    # print("type ws: ",type(ws))
    # print("dir  ws: ",dir(ws))

    if hasattr(request, "Sec-Websocket-Protocol"):
        print(request.headers["Sec-Websocket-Protocol"])
    else:
        print("INFO: No protocol specified")

    if request.headers["Sec-Websocket-Protocol"] == "aProtocol":
        print("INFO: protocol is OK")
    else:
        print("INFO: protocol not accepted: closing connection")
        ws.close()

    while not ws.closed:
        message = ws.receive()
        if message:
            print("received: "+message)
            ws.send(message)

    if ws.closed:
        print("INFO: connection has been closed")

if __name__ == "__main__":
    from gevent import pywsgi
    from geventwebsocket.handler import WebSocketHandler
    server = pywsgi.WSGIServer(('', 5001), app, handler_class=WebSocketHandler)
    server.serve_forever()

以下最小websocket客户端使用websocket库。文件名为app。js：

'use strict'

var WebSocketClient = require('websocket').client;
var client = new WebSocketClient();

function connectToServer(uri,protocol){
    client.on('connectFailed', function (error) {
        console.log('Connect Error: ' + error.toString());
    });

    client.on('connect', function (connection) {
        console.log('WebSocket Client Connected');

        connection.on('error', function (error) {
            console.log("Connection Error: " + error.toString());
        });

        connection.on('close', function () {
            console.log('echo-protocol Connection Closed');
        });

        connection.on('ping', () => {
            connection.pong();
        });

        connection.on('message', function (message) {
            if (message.type === 'utf8') {
                console.log("Received message is: '" + message.utf8Data + "'");
            }
        });
        console.log("sending SOMETHING");
        connection.sendUTF("SOMETHING");
    });
    client.connect(uri, protocol);
}

const wsHostAndPort = process.env.WSHSTPRT || "ws://echo.websocket.org:80";
const wsProtocol = process.env.WSPRTCL || []; // [] for no protocol

console.log("connecting to: ",wsHostAndPort,"with protocol",wsProtocol);
connectToServer(wsHostAndPort,wsProtocol);

启动python ws-server：

$ python3 ws_server.py

从nodejs ws客户端连接：

$ WSHSTPRT=ws://localhost:5001/ WSPRTCL="aProtocol" node app.js

客户端的输出是

connecting to:  ws://localhost:5001/ with protocol aProtocol
Connect Error: Error: Expected a Sec-WebSocket-Protocol header.

服务器终端的输出为：

request.headers:  Upgrade: websocket
Connection: Upgrade
Sec-Websocket-Version: 13
Sec-Websocket-Key: +QjH5xejDI+OQZQ0OZcWEQ==
Host: localhost:5001
Sec-Websocket-Protocol: aProtocol


INFO: No protocol specified
INFO: protocol is OK
INFO: connection has been closed

在我看来，python服务器需要设置一个名为“Sec WebSocket Protocol”的头，该头的值与它从客户端收到的值相同。但我不知道怎么做。到目前为止，我在互联网上搜索（主要是flask sockets和gevent websockets论坛和问题追踪器），没有任何运气。

我尝试了另一个简单的客户端，webSocat。我是这样调用它的：$webocatws://localhost:5001--------------------------------------------------------------------------------------------------------------------------它的工作原理是因为，我认为，webSocket（不像nodejs'webSocket）不希望在与服务器的握手中出现Sec-WebSocket协议头。

但是我需要使用nodejs客户端，它需要头。所以我的问题是：如何在python服务器握手响应中合并“Sec WebSocket协议”头？




Answer 1

匿名用户

我知道这是一年多前的事了，看起来你已经向前看了，尽管看起来你快到了，只是需要用服务器期望的子协议替换一个协议。

或者，完全省略，根据flask-webSocket使用的底层gevent-webSocket：

// Subprotocol (2nd parameter) often is not required at all
var ws = new WebSocket('ws://localhost:5001/api');

对于未来的我或任何在这里跌跌撞撞的人，我希望以下内容有所帮助。

在JavaScript中，将浏览器连接到节点。JS apollo服务器订阅，我需要以下内容：

// Pasted into Firefox console
const token = '...';  // A bearer token, if auth is needed
const subprotocol = 'graphql-ws';
w = new WebSocket('ws://localhost:5000/graphql', subprotocol);
w.send(JSON.stringify({"type":"connection_init","payload":{"authToken":token}}));

否则，如果没有应用子协议，没有发送Sec-WebSock-协议标头，并且控制消息可见，我会看到连接关闭： 1002，并且自然无法向webSock-发送消息：