title: How to return id of uploaded file (upload with multer in nodejs express app)
body: <p>I have an MEAN stack app and trying to upload file with multer. Upload is working fine the only problem is I want to return uploaded file's id. </p>
  
  <pre><code>//multer settings for single upload
  var upload = multer({ storage: storage }).single('file');
  
  app.post('/upload', upload, function (req, res) {
  //// ????? What to return and how? 
  });
  </code></pre>
  
  <p>I'm subscribed to this post into angular2 service. 
  Thank you for help.</p>