Docker Installation on Ubuntu

This guide explains how to install Docker Engine and its associated tools on Ubuntu, ensuring a clean, reliable setup for containerized applications.

1. Update and Upgrade the System

Always start by updating your package lists and upgrading existing packages to ensure your system is up-to-date:

sudo apt update && sudo apt upgrade -y

• apt update → refreshes the package index.
• apt upgrade -y → upgrades installed packages automatically.

2. Install Required Prerequisites

Install essential packages required for adding Docker repositories and handling HTTPS:

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

• ca-certificates → ensures secure HTTPS connections.
• curl → command-line tool to download files.
• gnupg → manages encryption keys.
• lsb-release → retrieves Ubuntu release information.

3. Add Docker’s GPG Key

Docker packages are signed. Add the official GPG key to verify package authenticity:

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