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If you’re a developer looking to deploy a Flask (Python) or Node.js (JavaScript) web application, using Docker on a Cloud VM is one of the best ways to ensure portability, scalability, and easy management.

In this guide, we’ll cover:
✅ Why Use Docker for Deployment?
✅ Choosing a Cloud VM Provider
✅ Deploying a Flask App in Docker
✅ Deploying a Node.js App in Docker

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🚀 Why Use Docker for Web App Deployment?

Docker provides containerization, allowing you to package your app and dependencies into a lightweight, portable container.

🔹 Benefits of Docker for Deployment:
✔️ Portability – Run the same container on any machine
✔️ Scalability – Easily scale up with multiple containers
✔️ Security – Isolates your app from the host system
✔️ Easy Updates – Deploy new versions with a single command

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☁️ Choosing a Cloud VM Provider

To host your application, you’ll need a Cloud VM provider. Some great options include:

🔹 Vultr Cloud VMs – Affordable and powerful VPS hosting
🔹 AWS EC2 – Enterprise-grade cloud computing
🔹 DigitalOcean Droplets – Easy-to-use Linux servers

💡 For this guide, we’ll use Vultr, but the steps apply to any cloud provider.

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🛠 Setting Up Your Cloud VM

1️⃣ Create a Cloud VM

• Sign up at Vultr
• Choose Ubuntu 22.04 as the OS
• Select at least 1GB RAM & 1 vCPU

2️⃣ Connect to Your Server
Once the VM is created, SSH into it:

ssh root@YOUR_VM_IP

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🐳 Installing Docker on Your Cloud VM

First, update your system:

sudo apt update && sudo apt upgrade -y

Then, install Docker:

sudo apt install -y docker.io

Verify Docker is installed:

docker --version

✅ Docker is now set up on your Cloud VM!

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🌍 Deploying a Flask App in Docker

Let’s deploy a simple Flask app inside a Docker container.

Step 1: Create the Flask App

First, create a new project directory:

mkdir ~/flask-app && cd ~/flask-app

Create app.py:

nano app.py

Add the following Flask code:

from flask import Flask

app = Flask(__name__)

@app.route('/')
def home():
    return "Hello, Flask in Docker!"

if __name__ == '__main__':
    app.run(host='0.0.0.0', port=5000)

Step 2: Create a Dockerfile

Next, create a Dockerfile:

nano Dockerfile

Add the following content:

# Use an official Python runtime as a base image
FROM python:3.9

# Set the working directory
WORKDIR /app

# Copy the application files
COPY app.py /app/

# Install Flask
RUN pip install flask

# Expose the app port
EXPOSE 5000

# Run the application
CMD ["python", "app.py"]

Step 3: Build and Run the Container

Now, build the Docker image:

docker build -t flask-app .

Run the container:

docker run -d -p 5000:5000 flask-app

Step 4: Access Your Flask App

Your app should now be running at:

http://YOUR_VM_IP:5000

🎉 You’ve deployed a Flask app using Docker!

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🌎 Deploying a Node.js App in Docker

Let’s now deploy a Node.js app in Docker.

Step 1: Create the Node.js App

mkdir ~/node-app && cd ~/node-app

Create server.js:

nano server.js

Add this Node.js code:

const express = require('express');
const app = express();

app.get('/', (req, res) => {
    res.send('Hello, Node.js in Docker!');
});

app.listen(3000, () => {
    console.log('Server is running on port 3000');
});

Step 2: Create a Dockerfile

nano Dockerfile

Add the following content:

# Use an official Node.js runtime as a base image
FROM node:16

# Set the working directory
WORKDIR /app

# Copy package.json and install dependencies
COPY package.json /app/
RUN npm install

# Copy the rest of the application files
COPY . /app/

# Expose the app port
EXPOSE 3000

# Run the application
CMD ["node", "server.js"]

Step 3: Create a package.json File

nano package.json

Add this content:

{
  "name": "docker-node-app",
  "version": "1.0.0",
  "main": "server.js",
  "dependencies": {
    "express": "^4.17.1"
  }
}

Step 4: Build and Run the Container

Build the Docker image:

docker build -t node-app .

Run the container:

docker run -d -p 3000:3000 node-app

Step 5: Access Your Node.js App

Your app should now be running at:

http://YOUR_VM_IP:3000

🎉 You’ve successfully deployed a Node.js app using Docker!

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☁️ Want a More Scalable Deployment? Use Docker Compose!

Instead of running multiple docker run commands, you can use Docker Compose to manage both Flask and Node.js containers in one file.

Create a docker-compose.yml file:

version: '3'
services:
  flask:
    build: ./flask-app
    ports:
      - "5000:5000"
  node:
    build: ./node-app
    ports:
      - "3000:3000"

Start both containers at once:

docker-compose up -d

🔥 Now both apps are running with a single command!

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🎯 Conclusion: Deploy Your Apps with Ease

By using Docker on a Cloud VM, you can:
✅ Easily deploy Python (Flask) and JavaScript (Node.js) apps
✅ Ensure your apps run consistently across environments
✅ Scale applications with Docker Compose

💻 Looking for a powerful Mini PC to self-host instead?
👉 Check Out AMD Mini PCs

☁️ Want a reliable Cloud VM for hosting?
👉 Deploy on Vultr

📖 Want to Master Linux for Server Deployments?
👉 Best Linux OS Books

🐍 Need More Python Knowledge?
👉 Top Python Books

🔥 Have questions? Drop them in the comments below! 🚀