Why Use Docker on Ubuntu Server?
Docker has revolutionized how developers manage applications through containerization technology. With Docker, you can wrap an application and all its dependencies into a single isolated unit, ensuring environment consistency between development and production stages. Ubuntu Server is a popular choice due to its stability and wide community support for the Docker ecosystem.
Step 1: Preparation and System Update
Before starting the installation, it is crucial to ensure that your system has the latest packages. This prevents dependency conflicts during the installation process. Run the following commands to update the package index and upgrade existing packages:
sudo apt-get update
sudo apt-get upgrade -yAfter that, we need to install several supporting packages so that Ubuntu can communicate with the Docker repository via HTTPS protocol:
sudo apt-get install ca-certificates curl gnupg lsb-release -yStep 2: Adding GPG Key and Official Repository
To ensure your system trusts the packages downloaded from the Docker server, you must add the official GPG Key. This step ensures data integrity and installation security.
sudo mkdir -p /etc/apt/keyrings
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /etc/apt/keyrings/docker.gpgNext, add the Docker repository to your Ubuntu package source list so that apt knows where to download the Docker Engine:
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/nullStep 3: Installing Docker Engine
Now it is time to install Docker Engine along with Docker Compose, a tool that allows you to run multi-container applications with a single YAML configuration file.
sudo apt-get update
sudo apt-get install docker-ce docker-ce-cli containerd.io docker-compose-plugin -yTo verify that Docker has been installed correctly and is running in the background, you can check the service status using the systemctl status docker command or try running the "hello-world" container.
Step 4: Post-Installation Configuration
By default, Docker commands can only be executed by users with root access or by using sudo. For better efficiency, you can add your user to the docker group so that you do not need to type sudo every time you run a container.
sudo usermod -aG docker $USERNote: After running the command above, you need to logout and log back in to the server so that the group changes are applied by the system.