Docker enables containerization of applications with their dependencies, providing a standardized deployment environment. This guide covers the installation process on Ubuntu 22.04.

System Update

Begin by updating the package repository and upgrading existing packages:

sudo apt update
sudo apt full-upgrade -y

Install Required Dependencies

Add essential packages for secure repository access:

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

Add Docker GPG Key

Import Docker's official GPG key for package verification:

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

Configure Docker Repository

Add the Docker repository to your system sources:

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

Refresh Package Index

Update the package list to include Docker packages:

sudo apt update

Install Docker Engine

Install the Docker components:

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

Start and Enable Docker Service

Activate Docker and configure it to start on boot:

sudo systemctl enable docker
sudo systemctl start docker

Verify Installation

Test the Docker installation with a sample container:

sudo docker run --rm hello-world

Successful output should display confirmation messages from the Docker container.

Non-Root User Access

Add your user to the docker group to run commands without sudo:

sudo groupadd docker
sudo usermod -aG docker $USER

Log out and back in for group membership changes to take effect, or use:

newgrp docker

Install Docker Compose

For managing multi-container applications, install Docker Compose:

sudo apt install docker-compose-plugin -y

Verify the installation with:

docker compose version