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Docker Installation on Ubuntu 22.04 LTS

Complete guide to install Docker Engine on Ubuntu 22.04.4 LTS server

Server Setup Last updated: October 28, 2025

Tested Environment: Ubuntu 22.04.4 LTS

Overview

This guide covers the installation of Docker Engine on Ubuntu 22.04 LTS using the official Docker repository. This method ensures you get the latest stable version with easy updates.

Prerequisites

  • Ubuntu 22.04.4 LTS (or compatible version)
  • User account with sudo privileges
  • Internet connection

Installation Steps

Step 1: Update System Packages

sudo apt update
sudo apt upgrade -y

Step 2: Remove Old Docker Versions

If you have any older versions of Docker installed, remove them first:

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

Step 3: Install Required Dependencies

sudo apt install -y \
    ca-certificates \
    curl \
    gnupg \
    lsb-release

Step 4: Add Docker’s Official GPG Key

sudo mkdir -p /etc/apt/keyrings
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /etc/apt/keyrings/docker.gpg

Step 5: Set Up Docker Repository

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

Step 6: Install Docker Engine

sudo apt update
sudo apt install -y docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin

Step 7: Verify Installation

sudo docker --version

Expected output:

Docker version 24.x.x, build xxxxxxx

Step 8: Test Docker Installation

sudo docker run hello-world

This command downloads a test image and runs it in a container. If successful, you’ll see a “Hello from Docker!” message.

Post-Installation Configuration

Add User to Docker Group

To run Docker commands without sudo:

# Add current user to docker group
sudo usermod -aG docker $USER

# Apply group changes (or logout/login)
newgrp docker

Verify you can run Docker without sudo:

docker run hello-world

Enable Docker to Start on Boot

sudo systemctl enable docker.service
sudo systemctl enable containerd.service

Check Docker Service Status

sudo systemctl status docker

Docker Compose Installation

Docker Compose is now included as a plugin. Verify installation:

docker compose version

Expected output:

Docker Compose version v2.x.x

Useful Docker Commands

Service Management

# Start Docker service
sudo systemctl start docker

# Stop Docker service
sudo systemctl stop docker

# Restart Docker service
sudo systemctl restart docker

# View Docker service logs
sudo journalctl -u docker.service

Container Management

# List running containers
docker ps

# List all containers (including stopped)
docker ps -a

# Stop a container
docker stop <container_id>

# Remove a container
docker rm <container_id>

# Remove all stopped containers
docker container prune

Image Management

# List downloaded images
docker images

# Pull an image from Docker Hub
docker pull <image_name>:<tag>

# Remove an image
docker rmi <image_id>

# Remove unused images
docker image prune

System Information

# Display system-wide information
docker info

# Show Docker disk usage
docker system df

# Remove all unused data
docker system prune -a

Testing with a Sample Application

Run Nginx Container

docker run -d -p 8080:80 --name my-nginx nginx:latest

Access Nginx in your browser:

http://your-server-ip:8080

Stop and remove the container:

docker stop my-nginx
docker rm my-nginx

Run Ubuntu Container

docker run -it ubuntu:22.04 bash

This starts an interactive Ubuntu container. Type exit to leave.

Docker Configuration Files

Main Configuration Locations

# Docker daemon configuration
/etc/docker/daemon.json

# Docker service configuration
/lib/systemd/system/docker.service

# Docker data directory
/var/lib/docker/

Configure Docker Daemon

Create or edit /etc/docker/daemon.json:

sudo nano /etc/docker/daemon.json

Example configuration:

{
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "10m",
    "max-file": "3"
  },
  "storage-driver": "overlay2"
}

Restart Docker after changes:

sudo systemctl restart docker

Troubleshooting

Permission Denied Error

If you get “permission denied” when running Docker:

# Check if user is in docker group
groups $USER

# If not in docker group, add user
sudo usermod -aG docker $USER

# Logout and login again, or run
newgrp docker

Docker Service Won’t Start

# Check service status
sudo systemctl status docker

# View detailed logs
sudo journalctl -xeu docker.service

# Check for configuration errors
sudo dockerd --validate

Port Already in Use

If a port is already in use:

# Find process using port 8080
sudo lsof -i :8080

# Kill the process
sudo kill -9 <PID>

Disk Space Issues

# Check disk usage
docker system df

# Clean up unused resources
docker system prune -a --volumes

# Remove specific items
docker container prune  # Remove stopped containers
docker image prune -a   # Remove unused images
docker volume prune     # Remove unused volumes

Security Best Practices

1. Keep Docker Updated

sudo apt update
sudo apt upgrade docker-ce docker-ce-cli containerd.io

2. Use Official Images

Always prefer official images from Docker Hub:

docker pull nginx:latest  # Official image

3. Run Containers as Non-Root

Avoid running containers with root privileges when possible:

docker run --user 1000:1000 <image>

4. Limit Container Resources

# Limit memory
docker run --memory="512m" <image>

# Limit CPU
docker run --cpus="1.5" <image>

5. Enable Docker Content Trust

export DOCKER_CONTENT_TRUST=1

Uninstalling Docker

If you need to uninstall Docker:

# Stop Docker service
sudo systemctl stop docker

# Remove Docker packages
sudo apt purge docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin

# Remove Docker data (WARNING: This deletes all images, containers, volumes)
sudo rm -rf /var/lib/docker
sudo rm -rf /var/lib/containerd

Next Steps

After installing Docker, consider:

  1. Learn Docker Compose: Create multi-container applications
  2. Explore Docker Hub: Find pre-built images for your needs
  3. Set up private registry: For production environments
  4. Configure monitoring: Use tools like Prometheus and Grafana
  5. Implement CI/CD: Integrate Docker into your deployment pipeline

Additional Resources

Common Use Cases

Run MySQL Database

docker run -d \
  --name mysql-db \
  -e MYSQL_ROOT_PASSWORD=my-secret-pw \
  -p 3306:3306 \
  mysql:8.0

Run PostgreSQL Database

docker run -d \
  --name postgres-db \
  -e POSTGRES_PASSWORD=my-secret-pw \
  -p 5432:5432 \
  postgres:15

Run Redis Cache

docker run -d \
  --name redis-cache \
  -p 6379:6379 \
  redis:latest

Verification Checklist

  • Docker service is running
  • User added to docker group
  • Can run docker ps without sudo
  • hello-world container runs successfully
  • Docker Compose is installed and working
  • Docker starts automatically on boot

References

  • Docker Engine: Container runtime and daemon
  • Docker Compose: Multi-container orchestration tool
  • containerd: Industry-standard container runtime
  • Default Docker port: 2375 (HTTP), 2376 (HTTPS)