How can I set cookie in node js using express framework?

In my application, I need to set a cookie using the express framework. I have tried the following code but it's not setting the cookie.

var express = require('express'), http = require('http');
var app = express();
app.configure(function(){
      app.use(express.cookieParser());
      app.use(express.static(__dirname + '/public'));

      app.use(function (req, res) {
           var randomNumber=Math.random().toString();
           randomNumber=randomNumber.substring(2,randomNumber.length);
           res.cookie('cokkieName',randomNumber, { maxAge: 900000, httpOnly: true })

           console.log('cookie have created successfully');
      });

});

var server = http.createServer(app);
var io = require('socket.io').listen(server);
server.listen(5555);

The order in which you use middleware in Express matters: middleware declared earlier will get called first, and if it can handle a request, any middleware declared later will not get called.

If express.static is handling the request, you need to move your middleware up:

// need cookieParser middleware before we can do anything with cookies
app.use(express.cookieParser());

// set a cookie
app.use(function (req, res, next) {
  // check if client sent cookie
  var cookie = req.cookies.cookieName;
  if (cookie === undefined) {
    // no: set a new cookie
    var randomNumber=Math.random().toString();
    randomNumber=randomNumber.substring(2,randomNumber.length);
    res.cookie('cookieName',randomNumber, { maxAge: 900000, httpOnly: true });
    console.log('cookie created successfully');
  } else {
    // yes, cookie was already present 
    console.log('cookie exists', cookie);
  } 
  next(); // <-- important!
});

// let static middleware do its job
app.use(express.static(__dirname + '/public'));

Also, middleware needs to either end a request (by sending back a response), or pass the request to the next middleware. In this case, I've done the latter by calling next() when the cookie has been set.

Update

As of now, the cookie parser is a separate npm package, so instead of using:

app.use(express.cookieParser());

you need to install it separately using npm i cookie-parser and then use it as:

const cookieParser = require('cookie-parser');
app.use(cookieParser());