Access Files from AWS S3 Bucket Using NodeJs

Here we will learn how to upload , download and delete
files in AWS S3 bucket using NodeJs

Step 1: Create a AWS account

• First we need to create a AWS account if we don't have one

• You may create a free tier account but you need to fill your card details there

Step 2: Initialize the Project

• Create a folder lets say 's3' in your desktop or wherever you
  want

• Open the terminal and direct their using cd command

  • cd desktop
  • cd s3

• Now add npm json file in it
  • npm init -y

• create a file 'app.js' in the folder s3

Step 3: Installing the required dependencies

• Install express, aws-sdk and multer in your folder i.e. s3
  • npm install express aws-sdk multer multer-s3

Step 4: S3 bucket setup

• Open the AWS console

• Now Search S3 there and then open S3

• Click on Create bucket option

• Set name and region there and unselect☑️ 'block all public access'

• select✅ 'Block public access to buckets and objects granted through new public bucket or access point policies'
  and 'Block public and cross-account access to buckets and objects through any public bucket or access point policies'

• Click on create bucket

congratulations your bucket is created

Step 5: Create AWS Credentials

• First click on 'Innominds'

• Then click on 'My security credentials'

• Then click on the 'Access key' and then 'Create New Access Key'

• You will get your access key there

Step 6: Create .env file

• Create a .env file in your s3 folder

• Inside .env file enter:-

  • ACCESS_KEY = (your access key)
  • ACCESS_SECRET = (your secret access key)
  • REGION = (region of your bucket)
  • BUCKET = (name of your bucket)

Step 7: Create a express server

• create express server inside the file 'app.js'

• Don't forget to add .env file to your 's3' folder
  -npm i dotenv

• Declare all the previously mentioned libraries like aws-sdk, multer, multer-s3 in your express server

Step 8: Use muller with aws-sdk to acccess the file

Here is one standard Example for Express server:-

require("dotenv").config()

const express = require('express')

const app = express();

app.listen(3001);

const aws = require('aws-sdk')
const multer = require('multer')
const multerS3 = require('multer-s3');

aws.config.update({
secretAccessKey: process.env.ACCESS_SECRET,
accessKeyId: process.env.ACCESS_KEY,
region: process.env.REGION,

});
const BUCKET = process.env.BUCKET
const s3 = new aws.S3();

const upload = multer({
storage: multerS3({
s3: s3,
acl: "public-read",
bucket: BUCKET,
key: function (req, file, cb) {
console.log(file);
cb(null, file.originalname)
}
})
})

app.post('/upload', upload.single('file'), async function (req, res, next) {

res.send('Successfully uploaded ' + req.file.location + ' location!')

})

app.get("/list", async (req, res) => {

let r = await s3.listObjectsV2({ Bucket: BUCKET }).promise();
let x = r.Contents.map(item => item.Key);
res.send(x)

})

app.get("/download/:filename", async (req, res) => {
const filename = req.params.filename
let x = await s3.getObject({ Bucket: BUCKET, Key: filename }).promise();
res.send(x.Body)
})

app.delete("/delete/:filename", async (req, res) => {
const filename = req.params.filename
await s3.deleteObject({ Bucket: BUCKET, Key: filename }).promise();
res.send("File Deleted Successfully")

})