How to Install Docker on Ubuntu 20.04. Docker is a open-source platform that uses OS-level virtualization to deliver software in packages called containers. Container is a unit of software that packages up code and all its dependencies so the application runs quickly and reliably from one computing environment to another.
Docker container technology was launched in 2013 which jump started a revolution in application development – by democratizing software containers.
In this guide you are going to learn how to install Docker on Ubuntu 20.04 LTS.
This setup is tested on Google Cloud Platform so it will work fine on any cloud servers or any VPS or any dedicated servers running Ubuntu 20.04.
- If you are on GCP, see the Setting up Compute Engine Instance.
Start by updating the packages to the latest version available.
sudo apt update
sudo apt upgrade
Step 1: Install Docker
Make sure you install the latest version of Docker from the official Docker repository. The official Ubuntu repository also has the Docker installation package, but it may not be the latest version.
Let’s start installing Docker.
Install some packages which allows you to use the packages over HTTPS.
sudo apt install apt-transport-https ca-certificates curl software-properties-common
Add the GPG key of Docker repository.
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
Now add the Docker repository of Ubuntu 20.04 (|
focal) to the
sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu focal stable"
Update the packages index and setup your server to install Docker from official Docker repo.
sudo apt update
sudo apt-cache policy docker-ce
You will receive an output similar to this.
500 https://download.docker.com/linux/ubuntu focal/stable amd64 Packages
Now you can install Docker.
sudo apt install docker-ce
Once Docker is installed and the process is enabled to start on boot.
To check the status of Docker you can use the following command.
sudo systemctl status docker
The output will be like this.
● docker.service - Docker Application Container Engine
Loaded: loaded (/lib/systemd/system/docker.service; enabled; vendor preset: enabled)
Active: active (running) since Fri 2020-05-22 09:18:43 UTC; 29s ago
Configure Sudo permissions for Docker
docker command can only be executed as root user by default. If you need to run the
docker command without sudo, you need to add your username to the docker group.
sudo usermod -aG docker username
Now restart your SSH or open a new terminal to see the changes.
From now you use the
docker command without sudo.
Using Docker Commands
To view the system information about Docker.
Download Docker Images
docker run hello-world
If the output you get is similar to the below then you can access and download images from Docker Hub.
Unable to find image 'hello-world:latest' locally
latest: Pulling from library/hello-world
0e03bdcc26d7: Pull complete
Status: Downloaded newer image for hello-world:latest
Hello from Docker!
This message shows that your installation appears to be working correctly.
Run the below command to see downloaded images.
Once you have started using Docker you will have many active and inactive containers.
To view all active containers, use the following command.
To view all containers which are active and inactive, use the below command.
docker ps -a
To view the latest container
docker ps -l
To start a docker container, use
docker start command followed by the Container ID or Container Name.
docker start container-id/name
Likewise to stop a running container you can use the
docker stop command followed by Container ID or Container Name.
docker stop container-id/name
If you no longer need the container you can remove the container with the
docker rm followed by Container ID or Container Name.
docker rm container-id/name
To enter into interactive shell you can use the following command.
docker run -it container-id/name
You can manually install commands inside the shell.
For more details about docker commands use the
docker run help command.
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Now you have learned how to install and manage Docker on Ubuntu 20.04.
Thanks for your time. If you face any problem or any feedback, please leave a comment below.