title: Files uploaded with multer disappears when the heroku server restarts
body: <p>I am using <code>multer</code> in <code>node.js</code> to upload files (that are coming from a client project based on Angular) to my Heroku server. Everything works fine, but when the Heroku server restarts or goes down all the uploaded files disappears, the <code>URL hits</code> returns '<code>Not Found</code>'.</p>
  
  <p>This is my code to upload files : </p>
  
  <pre><code>var express = require('express');
  var router = express.Router();
  var mysql = require('mysql');
  var multer = require('multer');
  var pool = require('./dbconnection');
  
  var storage = multer.diskStorage({
    destination: function (req, file, cb) {
      cb(null, '/app/public/images/postImages/')
    },
    filename: function (req, file, cb) {
      cb(null, file.fieldname + '-' + Date.now()+'.jpg')
    }
  })
  
  var upload = multer({ storage: storage })
  
  
  router.post('/postImages', upload.single('image'), function(req, res) {
  
  var userId              = req.body.userId;
  var postTitle           = req.body.postTitle;
  var postDesc            = req.body.postDesc;
  var postLat             = req.body.postLat;
  var postLng             = req.body.postLng;
  var postMediaType       = req.body.postMediaType;
  var postMediaFileName   = req.file.filename;
  var postMediaFilePath   = req.file.destination;
  var postMediaFileURL    = req.file.path;
  postMediaFileURL        = postMediaFileURL.substring(postMediaFileURL.indexOf('images/'), postMediaFileURL.length);
  
  var inserts = [postTitle, postDesc, postLat, postLng, postMediaType, postMediaFileName, postMediaFilePath, postMediaFileURL, userId];
  var sql = "INSERT INTO posts (postTitle, postDesc, postLat, postLng, postMediaType, postMediaFileName, postMediaFilePath, postMediaFileURL, userId) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)";
  sql = mysql.format(sql, inserts);
  console.log(sql);
  
  pool.getConnection(function(err, connection) {
      connection.query(sql, function(error, results) {
          connection.release();
          res.json(results);
          if(error) throw error;
      });
  });
  });
  
  module.exports = router;
  </code></pre>
  
  <p>Tell me what am I missing or what am I doing wrong.</p>