Docker 101: How to install Docker on Ubuntu Server 22.04

Compared to some other solutions, Docker is more user-friendly, offers plenty of GUI applications (so you don't have to always work from the command line), and is supported by Linux, macOS, and Windows.

Also: Docker 101: Why you should be using containers

I've deployed hundreds of applications and services with this tool and found it to be an invaluable component of my everyday workflow. In many cases, deploying the containerized application via Docker is much faster and more reliable than deploying the same app/service manually. 

I'm going to show you how to do just that. I'll demonstrate on Ubuntu Server 22.04, which means the process should work on any Ubuntu (or Debian) based distribution. As far as Red Hat Enterprise Linux-based distributions (such as Rocky Linux, AlmaLinux, CentOS Stream, and Feodra Linux), those platforms have migrated to Podman as their default container runtime, and installing Docker is not only very challenging, it tends to break more things than it fixes. 

So, if RHEL-based distributions are your jam, leave well enough alone and stick with Podman. However, if Ubuntu-based distributions are the way you lean, Docker is not only available, it's really easy to install. To that end, I'll be demonstrating on Ubuntu Server 22.04. To follow along, you'll need a Ubuntu-based distribution and a user with sudo privileges.

Ready? Let's get to the installation.

Installing on Ubuntu

1. Add the necessary repository

The first thing to do is log in to your Ubuntu instance and add the necessary repository (as the version of Docker found in the standard repository isn't the latest community edition we want). Once you've logged in, add the official Docker GPG key with the command:

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

Next, add the official Docker repository:

echo “deb [arch=amd64 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

2. Install the necessary dependencies

We'll next install the required dependencies with the command:

sudo apt-get install apt-transport-https ca-certificates curl gnupg lsb-release -y

3. Install Docker

Finally, update apt and install Docker with the following commands:

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

4. Add your user to the Docker group

In order to be able to use Docker without having to invoke it with sudo (which can lead to security issues), you must add your user to the docker group with:

sudo usermod -aG docker $USER

Log out and log back for the changes to take effect. 

Docker is now ready to use on your Ubuntu machine.

Testing the installation

Once Docker is installed, you can verify the installation by issuing the command:

In the output, you should see something like this:

Server: Docker Engine – Community
Engine:
Version: 20.10.14

Let's make sure your user can run a Docker command by pulling down the hello-world image with:

If the image successfully pulls, congratulations, Docker is installed and ready to go. Next time around, you'll learn how to deploy your first container with Docker.

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