How to resolve a Socket.io 404 (Not Found) error?

Question

I am using Socket.io with Express. In my project I have a login page and a home page. When I do successful login, I navigate to localhost:3000/home where I get this error:

GET http://localhost:3000/socket.io/?EIO=3&transport=polling&t=1418187395022-0 404 (Not Found)

I did not do any modification in my app.js (project created by express ).

index.js:

var express = require('express');
var router = express.Router();
var http = require('http');
var fs = require('fs');
var io = require('socket.io')(http);
/* GET home page. */
router.get('/', function(req, res) {
  res.render('index', { title: 'Express' });
});

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

io.on('connection', function(socket){
    console.log("User Connected");
  socket.on('chat message', function(msg){
    io.emit('chat message', msg);
    console.log("Message");
  });
   socket.on('disconnect', function(msg){
    console.log("User DisConnected");
  });

});

router.post('/authenticate', function(req, res) {
    fs.readFile("./public/Verification/Users.json", "utf8", function (err, data) {
        if (err) 
            console.log(err);
        else{
            var result = JSON.parse(data);
            for(var i=0;i<result.Users.length;i++){
                if(req.body.username == result.Users[i].username && req.body.password ==     result.Users[i].password){
                    console.log("Success!!!!!!!!!!!!!!");
                    res.location("home");
                    res.redirect("home");
                }
            }
        }
        });
});

module.exports = router;

In my layout.jade I defined Socket.io like this:

script(src='https://cdn.socket.io/socket.io-1.2.0.js')

Answer 1

If you're running Express 4, it appears to me like you're missing the lines of code:

var app = express();
var server = app.listen(3000);

That will start your web server and set it to port 3000. See the bone simple Express 4 app here: http://expressjs.com/4x/api.html

And, then to start up socket.io, you would add:

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

And, there is no need for this line:

var http = require('http');