express application to allow multiple origins

allow_multiple_origins.js

app.use(function(req, res, next) {
  var allowedOrigins = ['http://127.0.0.1:8020', 'http://localhost:8020', 'http://127.0.0.1:9000', 'http://localhost:9000'];
  var origin = req.headers.origin;
  if(allowedOrigins.indexOf(origin) > -1){
       res.setHeader('Access-Control-Allow-Origin', origin);
  }
  //res.header('Access-Control-Allow-Origin', 'http://127.0.0.1:8020');
  res.header('Access-Control-Allow-Methods', 'GET, OPTIONS');
  res.header('Access-Control-Allow-Headers', 'Content-Type, Authorization');
  res.header('Access-Control-Allow-Credentials', true);
  return next();
});

//OR Another Way 

app.all('/*', function(req, res, next) {
  // CORS headers
  res.header("Access-Control-Allow-Origin", "*"); // restrict it to the required domain
  res.header('Access-Control-Allow-Methods', 'GET,PUT,POST,DELETE,OPTIONS');
  // Set custom headers for CORS
  res.header('Access-Control-Allow-Headers', 'Content-type,Accept,X-Access-Token,X-Key');
  if (req.method == 'OPTIONS') {
    res.status(200).end();
  } else {
    next();
  }
});