How to Set Up Docker on Ubuntu 20.04, 22.04, and 24.04 LTS – From Installation to Multi-Container Deployment

🐳 Introduction to Docker

Docker simplifies app deployment by packaging code and dependencies into portable containers. It’s widely used for both development and production environments due to its consistency and efficiency.

🔧 Installing Docker on Ubuntu 20.04, 22.04, and 24.04 LTS

Step 1: Uninstall Old Versions (if any)

bash
sudo apt remove docker docker-engine docker.io containerd runc

Step 2: Update Packages & Install Dependencies

bash
sudo apt update sudo apt install apt-transport-https ca-certificates curl software-properties-common

Step 3: Add Docker’s GPG Key

bash
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg

Step 4: Add Docker’s Repository

bash
echo \ "deb [arch=$(dpkg --print-architecture) signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] \ https://download.docker.com/linux/ubuntu \ $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

Step 5: Install Docker Engine

bash
sudo apt update sudo apt install docker-ce docker-ce-cli containerd.io

Step 6: Verify Docker Installation

bash
sudo docker --version sudo docker run hello-world

📦 Getting and Creating Docker Images

Use Prebuilt Images (from Docker Hub)

bash
docker pull nginx docker pull node

Browse: https://hub.docker.com

Create Your Own Docker Image

Create a Dockerfile:

Dockerfile
# For Node.js app FROM node:18 WORKDIR /app COPY . . RUN npm install CMD ["npm", "start"] EXPOSE 3000

Then build it:

bash
docker build -t my-node-app .

🧰 Useful Docker Commands

CommandDescriptiondocker psShow running containersdocker imagesList local imagesdocker exec -it <id> bashEnter running containerdocker stop <id>Stop a containerdocker rm <id>Remove a containerdocker rmi <id>Remove an image

🕸️ Containerizing Multiple Servers (Frontend + Backend)

Folder structure:

project-root/ ├── backend/ │ └── Dockerfile ├── frontend/ │ └── Dockerfile └── docker-compose.yml

docker-compose.yml:

yaml
version: '3' services: frontend: build: ./frontend ports: - "3000:3000" depends_on: - backend backend: build: ./backend ports: - "5000:5000" environment: - NODE_ENV=production

Run everything:

bash
docker-compose up --build

Internal Networking

• Docker Compose automatically creates a default network.

• Services can communicate using their service name (frontend, backend) as hostname.

Example: Your frontend can make an API call to http://backend:5000/api.

✅ Wrapping Up

You now know how to:

• Install Docker on Ubuntu LTS

• Use Docker images and containers

• Build custom images

• Deploy full-stack apps using Docker Compose

• Utilize Docker networking for internal communication

Docker is an essential tool for modern DevOps and deployment workflows. Master it once, and you’ll level up your development and deployment pipeline.