How to install docker on Ubuntu: A Step-by-step guide

Docker introduction #

Docker is the modern platform for high-velocity innovation—a tool that is used to automate the deployment of applications in lightweight containers so that applications can work efficiently in different environments. 

A few quick notes about Docker:

• Multiple containers run on the same hardware
• Maintains isolated applications
• Enables high productivity
• Quick and easy to configure

Steps for Installing Docker #

1. Open the terminal on Ubuntu.

2. Remove any Docker files that are running in the system, using the following command:

sudo apt-get remove docker docker-engine docker.io containerd runc

After entering the above command, you will need to enter the password of the root and press enter.

3. Check if the system is up-to-date using the following command:

sudo apt-get update

4. To install Docker using snap, run the following command:

sudo snap install docker

5. You’ll then get a prompt asking you to choose between y/n – choose y

Or to install without snap, run the following command:

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

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
sudo apt-key fingerprint 0EBFCD88

sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"
sudo apt-get install docker-ce docker-ce-cli containerd.io

6. Before testing Docker, check the version installed using the following command:

docker --version

7. Pull an image from the Docker hub using the following command:

sudo docker run hello-world

Here, hello-world is the docker image present on the Docker hub.

8. Check if the docker image has been pulled and is present in your system using the following command:

sudo docker images

9. To display all the containers pulled, use the following command:

sudo docker ps -a

10. To check for containers in a running state, use the following command:

sudo docker ps

11. To add your user to docker group, use the following command:

sudo usermod -aG docker $USER
sudo reboot

You’ve just successfully installed Docker on Ubuntu!