Ws: unique identifier for each client request to websocket server

[altanai]

Trying to find out if any attribute of the websocket server module can be used to extract a unique identifier for each unique client connecting to server .
So far tried following ,

• ws._socket._handle.fd
• ws.upgradeReq.url.substr(1)

however each of them yields unpredictable value ( ie works and doesnt work at times)

Ps : I am using websocket never without using express

[lpinca]

You can add this info yourself every time a a new connection is established for example using node-uuid.

wss.on('connection', (ws) => {
  ws.id = uuid.v4();
});

or you can use a query parameter if you want to identify a client when it connects.

var ws = new WebSocket('ws://example.com/?token=abc123');

[fvukovic]

@lpinca Can u explain it how to fetch that token parameter on the server side?
I tried we.token it's undefined?

[lpinca]

@fvukovic

wss.on('connection', (ws, req) => {
  const { query: { token } } = url.parse(req.url, true);
  // ...
});

[sajadghawami]

@lpinca

wss.on('connection', (ws, req) => {
  const { query: { token } } = url.parse(req.url, true);
                                             ^
   TypeError: Cannot read property 'url' of undefined
});

[lpinca]

@sajadghawami use ws@>=3 or replace req with ws.upgradeReq.

[sajadghawami]

@lpinca

Still getting same error:

wss.on('connection', (ws, req) => {
  const { query: { token } } = url.parse(ws.upgradeReq.url, true);
                                                ^
   TypeError: Cannot read property 'url' of undefined
});

Using "ws": "^4.0.0"

[lpinca]

Reread my previous comment, upgrade or use upgradeReq, not both :). Since you are using ws@4 now the original snippet that uses req (https://github.com/websockets/ws/issues/859#issuecomment-362032885) is valid.

[sajadghawami]

Ahh i see :) ... but using the one you posted before didn't work either with ws@4...

you mean this:

wss.on('connection', (ws, req) => {
  const { query: { token } } = url.parse(req.url, true);
                                             ^
   TypeError: Cannot read property 'url' of undefined
});

[lpinca]

Yes that one, on ws@>=3, req can't be undefined so I think there is something wrong with your setup.
Run npm ls ws to see the installed ws version.

[R0lin]

Use request header 'sec-websocket-key'

wss.on('connection', (ws, req) => {
      var id = req.headers['sec-websocket-key'];

      //do what ever you want...
});

[matinsoleil]

wss.on('connection', function connection(ws,req) {
  var url = req.url;
  url = url.substring(1);
  room = 1;
  ws['room']= url;
// do any
});

[rigwild]

@fvukovic

wss.on('connection', (ws, req) => {
  const { query: { token } } = url.parse(req.url, true);
  // ...
});

url.parse is deprecated since Node v11. You can use the URL constructor instead.
Otherwise, you can simply do this if you only have one query parameter.

wss.on('connection', (ws, req) => {
  ws.uuid = req.url.replace('/?uuid=', '')
});