How to Install Docker on Ubuntu 20.04

Docker application is used to manage application processes in container. Using docker you can build, test and deploy applications that can run anywhere as portable and self-sufficient containers. In this tutorial, we will learn how to install Docker on Ubuntu 20.04.

Prerequisites#

Before you start install, you must have non-root user account with sudo privileges.

Installing Docker on Ubuntu#

We will install latest Docker package on Ubuntu system from the Docker’s repositories. Docker is also available in the standard Ubuntu 20.04 repositories, but it may not always be the latest version.

Perform the following steps to install docker on Ubuntu 20.04.

First, Update the package manager index list and upgrade the system to latest using below:

sudo apt update && sudo apt upgrade

We also need to install dependencies which are required to enable Docker repository.

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

Now Import the GPG key for repository using following curl command:

curl -fsSL https://download.docker.com/linux/debian/gpg | sudo apt-key add -

After that, add Docker repository to your system’s software repository list by typing:

sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/debian $(lsb_release -cs) stable"

Now Docker repository is enabled so update apt package manager index list again using below command:

sudo apt update

Install latest version of Docker Community Edition using below:

sudo apt install docker-ce

Once the installation completed the service of docker will start automatically. You can check it by issuing below command:

sudo systemctl status docker

● docker.service - Docker Application Container Engine
Loaded: loaded (/lib/systemd/system/docker.service; enabled; vendor preset: enabled)
Active: active (running) since Thu 2020-05-23 07:25:01 UTC; 42s ago
...

At the time of writing, the latest stable version of Docker is 19.03.1. You also can check the version of Docker using below command:

docker -v

Docker version 19.03.1, build 74b1e89

Executing docker command without sudo#

By default, Docker required sudo privileges to run. If you want to run docker command without sudo then you need to add your user to docker group. The docker group is created at the installation of docker CE package.

You should run below command to add user to docker group:

sudo usermod -aG docker $USER

After that, Log out and log back in to apply membership.

Run the below command to verify that you have added docker group :

id -nG

tecnstuff sudo docker

How to Use Docker Command#

Below is the basic syntax for the docker command:

docker [option] [subcommand] [arguments]

You can get list of all docker subcommands by issuing below command:

docker

If you need any help about subcommand then you can use following command:

docker docker-subcommand --help

Upgrading Docker#

You can update docker new version when it is released. You just have to run below commands:

sudo apt update

sudo apt upgrade

Uninstalling Docker#

Uninstall process of Docker is same as any other packages installed using apt:

sudo apt purge docker-ce

sudo apt autoremove

Conclusion#

You learned how to install docker on Ubuntu 20.04 system. To learn more about Docker check out the official Docker documentation.

If you have any question or suggestion, please leave a comment below.