Multer File Upload - you need to npm install and save multer and s3 (Amazon s3) - app.js is the front-end app.js, not the api app.js

app.js

function submitForm(){
	event.preventDefault();
	var $form = $(this)
	var method = $form.attr('method');
	var url = "http://localhost:3000" + $form.attr('action');
	var isFileUpload = $form.attr("enctype") === 'multipart/form-data';
	var data = $form.serialize();

	if(isFileUpload) {
		data = new FormData($form[0]);
	}

	if($(this).attr('action') === '/signup')
	$('.login-form').hide();
	$('#homes, .home-page-jumbo').show();
	return ajaxRequest(method, url, data, authenticationSuccessful, isFileUpload);
}

function ajaxRequest(method, url, data, callback, isFileUpload) {
	var options = {
		method: method,
		url: url,
		data: data,
		beforeSend: setRequestHeader
	};

	if(isFileUpload) {
		options.cache = false;
		options.enctype = 'multipart/form-data';
		options.processData = false;
		options.contentType = false;
	}

	return $.ajax(options)
	.done(function(data){
		callback(data);
	})
	.fail(function(data){
		console.log(data.responseJSON.message);
	});
}

homeController.js

function createHome(req, res) {
  console.log(req.file, req.body);
  User.findById(req.user._id, function(err, user){
    if(err) return res.render({messsage: 'Could not ceate home because ' + err});
    user.local.home = {
      type: req.body.type,
      home_image: req.file.key,
      description: req.body.description,
      address: req.body.address,
      postcode: req.body.postcode,
      pets: [req.body.pets],
      date_from: req.body.date_from,
      date_to: req.body.date_to
    };
    
    user.save(function(err){
      if(err) return res.status(500).json({message: 'Could not add home to user because ' + err});
      return res.status(200).json({ home: user.local.home });
    });
  });
};

routes.js

var multer = require('multer');
var s3 = require('multer-s3');

var upload = multer({
  storage: s3({
    dirname: 'homes/photos',
    bucket: process.env.AWS_BUCKET_NAME,
    secretAccessKey: process.env.AWS_SECRET_ACCESS_KEY,
    accessKeyId: process.env.AWS_ACCESS_KEY_ID,
    region: 'eu-west-1',
    filename: function (req, file, cb) {
      cb(null, file.originalname)
    }
  })
});

router.route('/api/homes')
  .get(homesController.getHomes)
  .post(upload.single('image'), homesController.createHome)