Install Docker on Ubuntu 20.04

In this tutorial, we will learn how to install docker on Ubuntu Linux.

Install docker using the repository:

For this, first set up the repository. Use the following command.

sudo apt-get update

sudo apt-get install \
    ca-certificates \
    curl \
    gnupg \
    lsb-release

Now, add docker's GPG key

sudo mkdir -p /etc/apt/keyrings

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

Now give sufficient permission

sudo chmod a+r /etc/apt/keyrings/docker.gpg

In order to set up the repository, use the following command

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

Now for installing Docker use the following command, which will install the latest docker.

sudo apt-get update & sudo apt-get install docker-ce docker-ce-cli containerd.io docker-compose-plugin

Install Docker using .deb package:

If we might have a problem with installing the docker with the above or wants to install a specific version of the docker then using .deb package is a good solution.

Download the desired version of .deb from here

In order to test the ubuntu version use the following command

lsb_release -a

we can get the output as below

No LSB modules are available.
Distributor ID:	Ubuntu
Description:	Ubuntu 20.04.3 LTS
Release:	20.04
Codename:	focal

Here, the codename is focal so We chose the same as above. Then browse to pool/stable/, choose amd64, armhf, arm64, or s390x, and download the .deb file

In order to test the CPU available use the following command

lscpu

Go to the download folder and execute the deb package using the following command

sudo dpkg -i docker-ce-cli_18.09.0_3-0_ubuntu-bionic_amd64.deb

Note: make sure to use your own version of the .deb package. Now start the docker

Now, we successfully install docker.

Check the Docker Version:

docker --version

Uninstall Docker:

Uninstall docker, CLI, Containerd, and Docker Compose packages using the following command

sudo apt-get purge docker-ce docker-ce-cli containerd.io docker-compose-plugin

Now, delete all images, containers, and volumes

sudo rm -rf /var/lib/docker
 sudo rm -rf /var/lib/containerd