uploading images in mlab

Question

currently i am storing images which are uploaded by node rest server in local directory "/uploads" . this is continuously increasing my repo size . to avoid this , i want to store image files in mongoDB atlas or mlab just like service.

    const express = require("express");
    const router = express.Router();
    const mongoose = require("mongoose");
    const multer = require('multer');

    const storage = multer.diskStorage({
      destination: function(req, file, cb) {
        cb(null, './uploads/');
      },
       filename: function(req, file, cb) {
        cb(null, new Date().toISOString() + file.originalname);
      }
    });

    const fileFilter = (req, file, cb) => {
     // reject a file
     if (file.mimetype === 'image/jpeg' || file.mimetype === 'image/png')           
     {
      cb(null, true);
      } else {
        cb(null, false);
     }
    };

    const upload = multer({
      storage: storage,
      limits: {
        fileSize: 1024 * 1024 * 5
      },
      fileFilter: fileFilter
    });

Please do help me in this. Thanks in advance.

Answer 1

You can achieve this by using a mongoose Schema and the fs core module to encode the image and unlink the file from /uploads.

I would start by creating a Mongoose Schema to set the model of all information you want to store pertaining to your uploaded file.

I'm going to use base64 encoding for this example.

uploadModel.js

const mongoose = require('mongoose');
const fs = require('fs');
const Schema = mongoose.Schema;

mongoose.set('useCreateIndex', true);

let uploadSchema = new Schema({
    name: {
      type: String,
    },
    mimetype: {
      type: String,
    },
    size: {
      type: Number,
    },
    base64: {
      type: String,
    }
})

module.exports = mongoose.model('upload',uploadSchema);

After setting up a model create a function to base64 encode and module.exports that as well.

To encode your file, use fs.readFileSync(path_to_file, encode_type). After the file has been encoded and saved in a variable you can use fs.unlink(path_to_file) to delete the file out of your /uploads folder.

uploadModel.js

module.exports.base64_encode = function(file) {
  return new Promise((resolve, reject) => {
    if(file == undefined){
      reject('no file found');
    } else {
      let encodedData = fs.readFileSync(file, 'base64');
      fs.unlink(file);
      resolve(encodedData.toString('base64'));
    }
  })
} 

Now inside your route file require your model.

route.js

const Upload = require('path_to_uploadModel');

router.post('/path_to_upload', upload.single('form_name_of_file'), (req, res) => {
  let img = req.file;

  let model = new Upload({
    name: img.originalname,
    size: img.size,
    mimetype: img.mimetype,
  })


  Upload.base64_encode(img.path)
    .then((base64) => {
      model['base64'] = base64;
      model.save((err)=> {
        if(err) throw err;
      });
    }
})

Hope this helps