Uploading image to amazon s3 using multer-s3 nodejs

Question

I am trying to upload an image to amazon s3 using multer-s3, but I am getting this error:

TypeError: Expected opts.s3 to be object node_modules/multer-s3/index.js:69:20

This is my server code:

var upload = multer({
    storage: s3({
        dirname: '/',
        bucket: 'bucket',
        secretAccessKey: 'key',
        accessKeyId: 'key',
        region: 'us-west-2',
        filename: function (req, file, cb) {
            cb(null, file.originalname); 
        }
    })
});

app.post('/upload', upload.array('file'), function (req, res, next) {
    res.send("Uploaded!");
});

Why I am getting this error?

Answer 1

Complete and working Node Cheat | Upload to s3 using multer-s3 available.

Code:

var express = require('express'),
    aws = require('aws-sdk'),
    bodyParser = require('body-parser'),
    multer = require('multer'),
    multerS3 = require('multer-s3');

aws.config.update({
    secretAccessKey: 'XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX',
    accessKeyId: 'XXXXXXXXXXXXXXX',
    region: 'us-east-1'
});

var app = express(),
    s3 = new aws.S3();

app.use(bodyParser.json());

var upload = multer({
    storage: multerS3({
        s3: s3,
        bucket: 'bucket-name',
        key: function (req, file, cb) {
            console.log(file);
            cb(null, file.originalname); //use Date.now() for unique file keys
        }
    })
});

//open in browser to see upload form
app.get('/', function (req, res) {
    res.sendFile(__dirname + '/index.html');//index.html is inside node-cheat
});

//use by upload form
app.post('/upload', upload.array('upl',1), function (req, res, next) {
    res.send("Uploaded!");
});

app.listen(3000, function () {
    console.log('Example app listening on port 3000!');
});

For complete repo:

Clone node-cheat express_multer_s3, run node app followed by npm install express body-parser aws-sdk multer multer-s3.

Happy Helping!

Answer 2

s3 needs to be an object to be passed. According to the docs, the object needs to be like this:

var upload = multer({
  storage: multerS3({
    s3: s3,
    bucket: 'some-bucket',
    metadata: function (req, file, cb) {
      cb(null, {fieldName: file.fieldname});
    },
    key: function (req, file, cb) {
      cb(null, Date.now().toString())
    }
  })
})

MulterS3 Docs

Answer 3

Zeeshan has answered very well still I want to add my 2 cents.

I believe in keeping one responsibility into one file, for better code organization and debugging purpose.

I have created a file for uploading upload.js.

require('dotenv').config();
const AWS = require('aws-sdk');
const multer = require('multer');
const multerS3 = require('multer-s3');

const s3Config = new AWS.S3({
    accessKeyId: process.env.AWS_IAM_USER_KEY,
    secretAccessKey: process.env.AWS_IAM_USER_SECRET,
    Bucket: process.env.AWS_BUCKET_NAME
  });

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

// this is just to test locally if multer is working fine.
const storage = multer.diskStorage({
    destination: (req, res, cb) => {
        cb(null, 'src/api/media/profiles')
    },
    filename: (req, file, cb) => {
        cb(null, new Date().toISOString() + '-' + file.originalname)
    }
})

const multerS3Config = multerS3({
    s3: s3Config,
    bucket: process.env.AWS_BUCKET_NAME,
    metadata: function (req, file, cb) {
        cb(null, { fieldName: file.fieldname });
    },
    key: function (req, file, cb) {
        console.log(file)
        cb(null, new Date().toISOString() + '-' + file.originalname)
    }
});

const upload = multer({
    storage: multerS3Config,
    fileFilter: fileFilter,
    limits: {
        fileSize: 1024 * 1024 * 5 // we are allowing only 5 MB files
    }
})

exports.profileImage = upload; 

Which is imported inside my routes routes.js

const express = require('express');

const ProfileController = require('../profile/controller');
const { profileImage } = require('../utils/upload.js'); 

 const routes = (app) => {
    const apiRoutes = express.Router();

    apiRoutes.use('/profile', profileRoutes);
    profileRoutes.post('/',profileImage.single('profileImage'), ProfileController.saveProfile);

    app.use('/api', apiRoutes);

 }

module.exports = routes

Postman screen shot for post body