20. How to Install Docker on Ubuntu Server: A Step-by-Step Guide to Containerization

Containerization has transformed application deployment by packaging software into isolated, lightweight environments that ensure consistency across different systems. Docker on Ubuntu Server is a powerful combination that simplifies this process, enabling developers and system administrators to build, ship, and run applications seamlessly. As the industry-leading containerization platform, Docker streamlines workflows and enhances scalability for modern application development.

In this guide, we’ll walk you through the steps to install Docker on Ubuntu Server and run your first containerized application. Whether you’re new to Docker or looking to optimize your deployment process, this tutorial will help you get started with containerization on Ubuntu Server.

Previous articles:

01. Introduction to Ubuntu Server – SysOSX: AI & Cloud

02. How to Setup Your First Ubuntu Server: A Beginner’s Guide – SysOSX: AI & Cloud

03.Mastering the Linux Command Line for Ubuntu Server – SysOSX: AI & Cloud

04. Managing Users and Permissions on Ubuntu Server: A Comprehensive Guide – SysOSX: AI & Cloud

05. Networking Basics for Ubuntu Server: A Comprehensive Guide – SysOSX: AI & Cloud

06. Installing and Managing Software on Ubuntu Server: A Complete Guide – SysOSX: AI & Cloud

07.Patching and Updating Ubuntu Server: A Comprehensive Guide – SysOSX: AI & Cloud

08. Securing Your Ubuntu Server: Practical Steps for Hardening and Protection – SysOSX: AI & Cloud

09. Ubuntu server auditing and logging

10. System Monitoring Tools for Ubuntu Server: A Comprehensive Guide – SysOSX: AI & Cloud

11. Centralized Logging for ubuntu server: a must read guide – SysOSX: AI & Cloud

12. Audit and Compliance for Ubuntu Server: Best Practices – SysOSX: AI & Cloud

13.Setting Up Your Ubuntu Server for Hosting and Web Applications: Ultimate Guide – SysOSX: AI & Cloud

14. Host Multiple Websites on a single Ubuntu Server: Useful tips – SysOSX: AI & Cloud

15. Managing Storage and Disks on Ubuntu Server: Simple Guide – SysOSX: AI & Cloud

16. Setting Up File Sharing Services on Ubuntu Server: a complete guide – SysOSX: AI & Cloud

17. Setting Up a Secure Database Server on Ubuntu: MySQL vs. MariaDB – SysOSX: AI & Cloud

18. How to Configure and Use LVM on Ubuntu Server: A Comprehensive Guide – SysOSX: AI & Cloud

19. Introduction to Virtualization with KVM: A Beginner’s Guide for Ubuntu Server – SysOSX: AI & Cloud

Prerequisites

Before installing Docker, ensure your Ubuntu Server meets these requirements:

• Ubuntu 20.04 LTS or later (64-bit).
• sudo privileges or root access.
• Stable internet connection for downloading packages.

Step 1: Install Docker on Ubuntu Server

Update System Packages

sudo apt update && sudo apt upgrade -y  

Install Required Dependencies

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

Add Docker’s Official GPG Key

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

Set Up Docker Repository

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  

Install Docker Engine

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

Verify Installation

sudo docker run hello-world  

If successful, you’ll see a confirmation message like below.

Step 2: Managing Docker as a Non-Root User

By default, Docker requires sudo privileges. To avoid typing sudo repeatedly:

1. Create a Docker Group (if not exists): sudo groupadd docker
2. Add Your User to the Group: sudo usermod -aG docker $USER
3. Apply Changes: newgrp docker

Step 3: Running Your First Container

Launch a Nginx web server in seconds:

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

• -d: Run in detached mode.
• -p 8080:80: Map host port 8080 to container port 80.
• --name: Assign a custom name to the container.

Verify Access:

curl http://localhost:8080  

Step 4: Essential Docker Commands

Step 5: Automate Workflows with Docker Compose

For multi-container applications, use Docker Compose:

• Install Docker Compose:

sudo apt install docker-compose -y

• Create a docker-compose.yml File:

version: '3'  
services:  
  web:  
    image: nginx  
    ports:  
      - "8080:80"  

• Start the Stack:

docker-compose up -d

Best Practices for Docker on Ubuntu

• Regularly Update Docker:

sudo apt update && sudo apt upgrade docker-ce -y

• Clean Unused Resources:

docker system prune -a

• Use Official Images from Docker Hub for security and reliability.

Troubleshooting Common Issues

• Permission Denied: Ensure your user is in the docker group.
• Port Conflicts: Check for other services using the same port.
• Image Pull Errors: Verify internet connectivity and image name spelling.

Docker vs. Other Containerization Tools

While Docker dominates the containerization landscape, understanding alternatives helps choose the right tool for your use case:

Why Docker Still Shines

• Beginner-friendly: Simplified workflow for app development and testing.
• Portability: Containers run identically across macOS, Windows, and Linux.
• Community support: Over 8 million Docker Hub images and extensive documentation.

When to Consider Alternatives

• LXD: Need full OS isolation (e.g., hosting multiple services with separate users).
• Podman: Prioritize security (e.g., government/healthcare workloads).
• containerd/CRI-O: Building Kubernetes-native infrastructure.

Conclusion

By following this guide, you’ve installed Docker on Ubuntu Server and deployed your first containerized application. Docker’s flexibility makes it indispensable for DevOps, cloud-native development, and hybrid environments. Explore advanced features like Docker Swarm or Kubernetes integration to scale your container workloads.

Reference: Docker Official Documentation

What’s Next? Get Ready to Explore LXD for Linux Containers

Now that you’ve mastered Docker for application containerization, let’s dive deeper into the world of Linux system containers! Stay tuned for our upcoming guide:

“Introduction to LXD for Linux Containers: Lightweight Virtualization Made Simple“