Use Contabo Object Storage with NodeJS

Use Contabo Object Storage with NodeJS

A simple guide to interacting with Contabo Object Storage from JavaScript using the AWS S3 SDK

Linus Benkner's photo
Linus Benkner
ยทMar 29, 2022ยท

8 min read

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Table of contents

  • Get your Object Storage
  • Create a bucket
  • Get the access keys
  • Setting up NodeJS and Express
  • Create the routes
  • Full Code
  • Python3 and Flask

Hi there! ๐Ÿ‘‹

Recently, Contabo launched their new storage solution Object Storage. These object storages provide an S3 compatible API and can be used quite easily - in this post, I show you how.

You can find the full source code for both NodeJS and Python3/Flask at the bottom.

Get your Object Storage

To follow along, you first need your own Object Storage. You can go directly to Contabo and order your Object Storage now. After you've completed the purchase, you can log in to your customer panel and select "Object Storage" in the sidebar. If you've never done this before, you'll be asked to set a password for the Object Storage Panel. After you've set your password, you can log in to the Object Storage Panel with your Contabo Email and the newly set password.

Now navigate to "Storage" - "Object Storage (Buckets)" in the sidebar and you should see your new Object Storage. Perfect!

Contabo Object Storage Panel - Storage Overview I didn't find an option to change the language in this panel, so everything is in german, I'm sorry :(

Create a bucket

Your files are organized in buckets, so let's create our first bucket. Below your Object Storage in the Object Storage Panel is a button to create a new bucket.

Create a new bucket for your storage in the Object Storage Panel

Now name your bucket and choose a region where your bucket should be located. Create it and you should see your new bucket on the list.

Get the access keys

To connect with the S3 API of your storage, we need two keys to authenticate:

  1. The Access Key and
  2. the Secret Key.

You can generate them in the Object Storage Panel by navigating to "Account" - "Security and access". Scroll down to the section "S3 Object Storage". That's where you can see both tokens. If you don't, click "Regenerate secret key" to create a new secret key.

We'll need both keys later when connecting to the S3 API.

Setting up NodeJS and Express

For this example, I'll build a simple webserver with ExpressJS to handle file uploads and also return all currently stored files.

Open up a new folder and initialize a new npm project. We also need express for our webserver and aws-sdk to interact with the S3 API, so we install them too:

npm init -y
npm i express aws-sdk

To get started we first need the webserver, so let's start express:

// index.js
const express = require("express")
const AWS = require("aws-sdk")

const app = express()

/* 
 * Code goes here
 */

app.listen(4000, function() {
    console.log("๐Ÿš€ App is running on http://localhost:4000")
})

Create the routes

For this simple project we need 3 routes:

  1. GET /: The form to upload a file to our express server
  2. POST /upload: The form handler to upload the file to the storage bucket
  3. GET /list: A list of all files inside the storage bucket

Show the form

Well, before we can show a form, we first need a form. For this demo, I just created a quick HTML page form.html with a simple form on it to upload a file. Notice the form action /upload, this points to the route handling the file upload, and also the method post.

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>File Upload</title>
</head>
<body>
    <h1>Upload a file to Contabo Object Storage</h1>

    <form action="/upload" method="POST" enctype="multipart/form-data">
        <input type="file" accept="image/png,image/jpeg" name="fileToUpload" />
        <button type="submit">Upload the file</button>
    </form>
</body>
</html>

All we have left to do is use express to send the file on each GET request to the root path:

// Show the form
app.get("/", function(request, response) {
    response.sendFile(__dirname + "/form.html") // <- Point this to your HTML file containing the form
})

Done! You can test it by running node index.js to start the express server and open http://localhost:4000 in your browser. You should see the form.

Simple HTML form to upload a file

Handle the file upload

To handle the file upload, we need the express-fileupload package to parse incoming multipart/form-data requests and extract the files:

npm i express-fileupload

And of course import it at the top of our index.js file:

const express = require("express")
const AWS = require("aws-sdk")

const fileUpload = require('express-fileupload') // NEW

Express-Fileupload is a middleware, so we need to register it to our express app:

const app = express()

// Middleware to handle incoming files
app.use(fileUpload({
    createParentPath: true
}))

In the next step, we create the actual route to handle the POST request with the file to upload:

// Handle files
app.post("/upload", function(request, response) {
    const file = request?.files?.["fileToUpload"] || null

    // Return if the request doesn't contain the file
    if(!file) return response.sendStatus(400)

    /*
     * TODO Upload the file to the storage bucket
     */

    response.sendStatus(200)
})

Connect to the S3 API

Things are getting real, we'll now connect to the S3 API to interact with our storage bucket!

Right after we create the express app by calling express(), let's create the connection to the S3 API:

const app = express()

// Connect to S3
const s3 = new AWS.S3({
    endpoint: `contabo_storage_bucket_url`, // e.g. https://eu2.contabostorage.com/bucketname
    accessKeyId: "your_access_key_here",
    secretAccessKey: "your_secret_key_here",
    s3BucketEndpoint: true,
});

We can now use all the S3 functions with our new s3 variable.

Upload the file

Back in our POST /upload route, we need to parse the data from the file:

// inside POST /upload route
const file = request?.files?.["fileToUpload"] || null

// Return if the request doesn't contain the file
if(!file) return response.sendStatus(400)

// Destructure the content of the file object
const { name, mimetype, size, data } = file
const fileContent  = Buffer.from(data, ' ');

We can now call the s3.putObject function to upload a file to the storage bucket.

// Handle files
app.post("/upload", function(request, response) {
    const file = request?.files?.["fileToUpload"] || null

    // Return if the request doesn't contain the file
    if(!file) return response.sendStatus(400)

    // Destructure the content of the file object
    const { name, mimetype, size, data } = file
    const fileContent  = Buffer.from(data, ' ');

    /* Add security checks (e.g. max size) here */

    s3.putObject({
        Body: fileContent, // The actual file content
        Bucket: "bucket_name",
        Key: name, // The name of the file
    }, function(err, data) {
        if (err) {
            response.sendStatus(500)
        } else {
            response.sendStatus(200)
        }
    });
})

Note: This is for demo purposes only. When used in production, make sure you validate the file before uploading (name, file size, file type, ...). I've added a comment in the code below where you should validation and security checks.

List all the files

You may want to show all uploaded files (e.g. inside a media browser), so let's also implement the route to list all files inside the bucket. For this demo, I'll just return the full result from the S3 API as JSON, but you can do whatever you want with it.

// Show all files
app.get("/list", function(request, response) {
    // Get all objects inside the bucket
    s3.listObjects({
        Bucket: "bucket_name",
    }, function (err, data) {
        if (err) {
            response.sendStatus(500)
        } else {
            // Return the list ("Contents") as JSON
            response.json(data.Contents)
        }
    })
})

JSON list of all objects in the storage bucket

Full Code

const express = require("express")
const AWS = require("aws-sdk")

const fileUpload = require('express-fileupload')

const app = express()

// Connect to S3
const s3 = new AWS.S3({
    endpoint: `contabo_storage_bucket_url`, // e.g. https://eu2.contabostorage.com/bucketname
    accessKeyId: "your_access_key_here",
    secretAccessKey: "your_secret_key_here",
    s3BucketEndpoint: true,
});

// Middleware to handle incoming files
app.use(fileUpload({
    createParentPath: true
}))

// Show the form
app.get("/", function(request, response) {
    response.sendFile(__dirname + "/form.html")
})

// Handle files
app.post("/upload", function(request, response) {
    const file = request?.files?.["fileToUpload"] || null

    // Return if the request doesn't contain the file
    if(!file) return response.sendStatus(400)

    // Destructure the content of the file object
    const { name, mimetype, size, data } = file
    const fileContent  = Buffer.from(data, ' ');

    /* Add security checks (e.g. max size) here */

    s3.putObject({
        Body: fileContent,
        Bucket: "your_bucket",
        Key: name,
    }, function(err, data) {
        console.log(err, data)
        if (err) {
            response.sendStatus(500)
        } else {
            response.sendStatus(200)
        }
    });
})

// Show all files
app.get("/list", function(request, response) {
    // Get all objects inside the bucket
    s3.listObjects({
        Bucket: "your_bucket",
    }, function (err, data) {
        if (err) {
            response.sendStatus(500)
        } else {
            // Return the list ("Contents") as JSON
            response.json(data.Contents)
        }
    })
})

app.listen(4000, function() {
    console.log("๐Ÿš€ App is running on http://localhost:4000")
})

Python3 and Flask

from flask import Flask, render_template, request  # pip install flask
import boto3  # pip install boto3
import os
from werkzeug.utils import secure_filename
app = Flask(__name__)

session = boto3.session.Session()
client = session.client('s3',
                        region_name='eu2',
                        # e.g. https://eu2.contabostorage.com
                        endpoint_url='contabo_storage_bucket_url',
                        aws_access_key_id='your_access_key_here',
                        aws_secret_access_key='your_secret_key_here')


@app.route('/')
def show_form():
    return render_template('form.html')  # located in templates/form.html


@app.route('/upload', methods=['POST'])
def handle_upload():
    f = request.files['fileToUpload']  # Get the file
    filename = secure_filename(f.filename)
    f.save(filename)  # Save the file temporarily
    client.upload_file(filename,  # Path to local file
                       'your_bucket',  # Bucket name
                       filename)  # Name for remote file
    os.remove(filename)  # Remove the file after uploading
    return 'Done!'


if __name__ == '__main__':
    app.run(debug=True)

And that's it - now you know how to upload files to your Contabo Object Storage! ๐Ÿฅณ

Thank you very much for reading and don't forget to follow me on Twitter @EinLinuus and also here on Hashnode and get notified everytime I publish a new post. ๐Ÿ™Œ

Have a nice day ๐Ÿš€๐Ÿ‘‹

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