如何使用nodejs中的ws npm模块从客户端向WebSocket服务器发送“升级”握手？

Question

I am using ws npm module to build my WebSocket client and server in nodejs

From client I have to send a "Upgrade" handshake request to the server with some specified protocols to the server.

From the client side, this is what I use to make a conenction to the server.

const ws = new WebSocket('ws://localhost:8989/');
ws.on('open', function open() {
          console.log('Connected to Server');
          })

And this is my handshake request,

GET <target> HTTP/1.1
Upgrade: websocket
Connection: Upgrade
Sec-WebSocket-Key: x3JJHMbDL1EzLkh9GBhXDw==
Sec-WebSocket-Protocol: com.xxx.service.v1
Sec-WebSocket-Version: 13

How should I add Upgrade headers and protocols to my client side connection request using ws npm module and how should I interpret them in server side?

This is my sample server side code,

var port: number = 8989;
var WebSocketServer = WebSocket.Server;
var wss = new WebSocketServer({ port: port });

wss.on('connection', (ws: WebSocket) => {
    console.log('Web Socket Server Connected');
});

I cant figure how to send these these Upgrade headers via ws client and how to interpret them in the server side?

After this handshake, I have to send a preamble via websocket text message.

Please suggest.

Thanks

Answer 1

Some web services like heroku handle this for you, but others like openshift doesn't it. Just try 'wss' intead of 'ws in the url string.

If you want to do this on localhost try to use https module instead of http. And if you need to do it manualy, try setting the headers when creating the websocket

    var wss = new WebSocketServer({ port: port,
                                    aField: 'aValue',
                                    anotherField: 'anotherValue' });

Where you setting the port you can set the headers too, but you must to know the correct fields to set for the browser to accept them.