ozenero | Mobile & Web Programming Tutorials

In the tutorial, we show how to build a Node.js/Express RestAPIs to Upload Files to Amazon S3 using Multer middleware and AWS-SDK.

Node.js Tutorial

Technologies

Node.js
Express
Multer
AWS-SDK
Amazon S3

Overview

Demo

Goal

We create a Node.js project as below ->

Expose a RestAPI: '/api/file/upload'

Upload File ->

Amazon S3 ->

Practice

Setting up Node.js project

Create a folder NodejsUploadFileAmazonS3, then init Node.js project ->

>npm init
This utility will walk you through creating a package.json file.
It only covers the most common items, and tries to guess sensible defaults.

See `npm help json` for definitive documentation on these fields
and exactly what they do.

Use `npm install ` afterwards to install a package and
save it as a dependency in the package.json file.

Press ^C at any time to quit.
package name: (nodejsuploadfileamazons3)
version: (1.0.0)
description: Node.js Express RestAPIs upload file to Amazon S3 using Multer, AWS-SDK
entry point: (index.js) server.js
test command:
git repository:
keywords: Nodejs, Express, Amazon S3, RestAPI, Upload File, Multer, Aws SDK
author: ozenero.com
license: (ISC)
About to write to D:\gkz\article\NodejsUploadFileAmazonS3\package.json:

{
  "name": "nodejsuploadfileamazons3",
  "version": "1.0.0",
  "description": "Node.js Express RestAPIs upload file to Amazon S3 using Multer, AWS-SDK",
  "main": "server.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [
    "Nodejs",
    "Express",
    "Amazon",
    "S3",
    "RestAPI",
    "Upload",
    "File",
    "Multer",
    "Aws",
    "SDK"
  ],
  "author": "ozenero.com",
  "license": "ISC"
}


Is this ok? (yes) yes

Install Express, Multer, AWS-SDK ->

npm install express multer aws-sdk --save

-> package.json file:

{
  "name": "nodejsuploadfileamazons3",
  "version": "1.0.0",
  "description": "Node.js Express RestAPIs upload file to Amazon S3 using Multer, AWS-SDK",
  "main": "server.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [
    "Nodejs",
    "Express",
    "Amazon",
    "S3",
    "RestAPI",
    "Upload",
    "File",
    "Multer",
    "Aws",
    "SDK"
  ],
  "author": "ozenero.com",
  "license": "ISC",
  "dependencies": {
    "aws-sdk": "^2.302.0",
    "express": "^4.16.3",
    "multer": "^1.3.1"
  }
}

Multer Config

– Create ./app/config/multer.config.js file:

const multer = require('multer');
 
var storage = multer.memoryStorage()
var upload = multer({storage: storage});
 
module.exports = upload;

AWS S3 Config

– Create a file ./app/config/s3.env.js ->

const env = {
	AWS_ACCESS_KEY: 'AKIAJMIPBAVVXRVB4AWA', // change to yours
	AWS_SECRET_ACCESS_KEY: 'lu3aELpRhETjw9xC+Qs5VhCpqkP+6VPoEL4khwxL', // change to yours
	REGION : 'us-east-2', // change to yours
	Bucket: 'ozenero-s3-bucket' // change to yours
};

module.exports = env;

– Configure S3 Client in a file ./app/config/s3.config.js ->

const AWS = require('aws-sdk');
const env = require('./s3.env.js');

const s3Client = new AWS.S3({
    accessKeyId: env.AWS_ACCESS_KEY,
    secretAccessKey: env.AWS_SECRET_ACCESS_KEY,
	region : env.REGION
});

const uploadParams = {
         Bucket: env.Bucket, 
         Key: '', // pass key
         Body: null, // pass file body
};

const s3 = {};
s3.s3Client = s3Client;
s3.uploadParams = uploadParams;

module.exports = s3;

Express Routers

– Create router in file ./app/routers/upload.router.js ->

let express = require('express');
let router = express.Router();
let upload = require('../config/multer.config.js');
 
const awsWorker = require('../controllers/aws.controller.js');
 
router.post('/api/file/upload', upload.single("file"), awsWorker.doUpload);
 
module.exports = router;

Upload Controller

– Implement S3 Uploader in a controller file ./app/controllers/aws.controller.js ->

var stream = require('stream');
 
const s3 = require('../config/s3.config.js');
 
exports.doUpload = (req, res) => {
	const s3Client = s3.s3Client;
	const params = s3.uploadParams;
	
	params.Key = req.file.originalname;
	params.Body = req.file.buffer;
		
	s3Client.upload(params, (err, data) => {
		if (err) {
			res.status(500).json({error:"Error -> " + err});
		}
		res.json({message: 'File uploaded successfully! -> keyname = ' + req.file.originalname});
	});
}

Server.js

– server.js file ->

const express = require('express');
const app = express();
 
let router = require('./app/routers/upload.router.js');
app.use('/', router);
 
// Create a Server
const server = app.listen(8080, function () {
 
  let host = server.address().address
  let port = server.address().port
 
  console.log("App listening at http://%s:%s", host, port); 
})

SourceCode

Use npm install to install all dependencies before run the Node.js server with cmd npm start.

– NodejsUploadFileAmazonS3