ExpressJS & Websocket & session sharing

I found this works for me. Not sure it’s the best way to do this though. First, initialize your express application:

// whatever your express app is using here...
var session = require("express-session");
var sessionParser = session({
    store: session_store,
    cookie: {secure: true, maxAge: null, httpOnly: true}
});
app.use(sessionParser);

Now, explicitly call the session middleware from the WS connection. If you’re using the express-session module, the middleware will parse the cookies by itself. Otherwise, you might need to send it through your cookie-parsing middleware first.

If you’re using the websocket module:

ws.on("request", function(req){
    sessionParser(req.httpRequest, {}, function(){
        console.log(req.httpRequest.session);
        // do stuff with the session here
    });
});

If you’re using the ws module:

ws.on("connection", function(req){
    sessionParser(req.upgradeReq, {}, function(){
        console.log(req.upgradeReq.session);
        // do stuff with the session here
    });
});

For your convenience, here is a fully working example, using express, express-session, and ws:

var app = require('express')();
var server = require("http").createServer(app);
var sessionParser = require('express-session')({
    secret:"secret",
    resave: true,
    saveUninitialized: true
});
app.use(sessionParser);

app.get("*", function(req, res, next) {
    req.session.working = "yes!";
    res.send("<script>var ws = new WebSocket('ws://localhost:3000');</script>");
});

var ws = new require("ws").Server({server: server});
ws.on("connection", function connection(req) {
    sessionParser(req.upgradeReq, {}, function(){
        console.log("New websocket connection:");
        var sess = req.upgradeReq.session;
        console.log("working = " + sess.working);
    });
});

server.listen(3000);