Socket.io 1.0 + express 4.2 = no socket connection

Question

As stated in title, I'm trying to use socket.io 1.0.4 with express 4.2, and all /?EIO requests return 404.

Bellow there are my files:

./bin/www :

#!/usr/bin/env node
var debug = require('debug')('generated-express-app');
var app = require('../app');

app.set('port', process.env.PORT || 3000);

var server = app.listen(app.get('port'), function() {
  debug('Express server listening on port ' + server.address().port);
});

./app.js :

var express = require('express');
var path = require('path');
var favicon = require('static-favicon');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');

var app = express();


// Extras para Socket.io
// var server = require('http').Server(app);
// var io = require('socket.io')(server);

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');

app.use(favicon());
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded());
app.use(cookieParser());
app.use(require('less-middleware')(path.join(__dirname, 'public')));
app.use(express.static(path.join(__dirname, 'public')));

// Requests

app.get('/', function (req, res) {
    res.render('index', { title: 'Express' });
});

// Socket requests
//
//io.on('connection', function (socket) {
//    socket.emit('news', { hello: 'world' });
//    socket.on('my other event', function (data) {
//        console.log(data);
//    });
//});

/// catch 404 and forward to error handler
app.use(function(req, res, next) {
    var err = new Error('Not Found');
    err.status = 404;
    next(err);
});

/// error handlers

// development error handler
// will print stacktrace
if (app.get('env') === 'development') {
    app.use(function(err, req, res, next) {
        res.status(err.status || 500);
        res.render('error', {
            message: err.message,
            error: err
        });
    });
}

// production error handler
// no stacktraces leaked to user
app.use(function(err, req, res, next) {
    res.status(err.status || 500);
    res.render('error', {
        message: err.message,
        error: {}
    });
});

module.exports = app;

var server = require('http').createServer(app);
server.listen(app.get('port'), function(){
    console.log('Express listening on port ' + app.get('port'));
});

var io = require('socket.io').listen(server);

io.sockets.on('connection', function (socket) {
    socket.emit('news', { hello: 'world' });
    socket.on('my other event', function (data) {
        console.log(data);
    });
});

Answer 1

I fiddled more with my files, and got it to work, here is how I got it to work:

./bin/www : Need to keep the require app.js , or it won't work.

#!/usr/bin/env node
//var debug = require('debug')('generated-express-app');
var app = require('../app');

//app.set('port', process.env.PORT || 3000);
//
//var server = app.listen(app.get('port'), function() {
//  debug('Express server listening on port ' + server.address().port);
//});
//
//var io = require('socket.io').listen(server);
//
//io.sockets.on('connection', function (socket) {
//    socket.emit('news', { hello: 'world' });
//    socket.on('my other event', function (data) {
//        console.log(data);
//    });
//});

./app.js : All that was on www goes here, before the last export.

var express = require('express');
var path = require('path');
var favicon = require('static-favicon');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');

var app = express();


// Extras para Socket.io
// var server = require('http').Server(app);
// var io = require('socket.io')(server);

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');

app.use(favicon());
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded());
app.use(cookieParser());
app.use(require('less-middleware')(path.join(__dirname, 'public')));
app.use(express.static(path.join(__dirname, 'public')));

// Requests

app.get('/', function (req, res) {
    res.render('index', { title: 'Express' });
});

// Socket requests
//
//io.on('connection', function (socket) {
//    socket.emit('news', { hello: 'world' });
//    socket.on('my other event', function (data) {
//        console.log(data);
//    });
//});

/// catch 404 and forward to error handler
app.use(function(req, res, next) {
    var err = new Error('Not Found');
    err.status = 404;
    next(err);
});

/// error handlers

// development error handler
// will print stacktrace
if (app.get('env') === 'development') {
    app.use(function(err, req, res, next) {
        res.status(err.status || 500);
        res.render('error', {
            message: err.message,
            error: err
        });
    });
}

// production error handler
// no stacktraces leaked to user
app.use(function(err, req, res, next) {
    res.status(err.status || 500);
    res.render('error', {
        message: err.message,
        error: {}
    });
});

var debug = require('debug')('generated-express-app');
//var app = require('../app');

app.set('port', process.env.PORT || 3000);

var server = app.listen(app.get('port'), function() {
    debug('Express server listening on port ' + server.address().port);
});

var io = require('socket.io').listen(server);

io.sockets.on('connection', function (socket) {
    socket.emit('news', { hello: 'world' });
    socket.on('my other event', function (data) {
        console.log(data);
    });
});

module.exports = app;

I used the express generator to gen the project, disabled the routes, as it seems that Socket.io won't support express routes.

Answer 2

So, one year later, and more node studies later, I found that the previous answer is quite incomplete, and may lead to sub-optimal usage of express. This is the more correct approach to use Node + Express + Socket.io without problems:

On /bin/www.js , replace var http = require('http'); with var server = require('http').Server(app); , and remove var server = http.createServer(app);

And that's it... Use your routes normally, place chats anywhere, no problems anymore.

Note : I left the old response unedited to preserve comments and such relevant and on context.