I realise that there are numerous flavours of Linux, but Ubuntu seems to be the most pervasive, so that’ll be the focus here. Official instructions for other flavours can be found here:
The following instructions will all be run in a terminal, so start by launching a terminal window.
CLI
Update the package list.
sudo apt-get update
Install Docker.
sudo apt-get install -y docker.io
At this point you need to have root privilege to interact with Docker. However, you can confer this privilege on other users too.
sudo gpasswd -a ubuntu docker
Login again the ubuntu user will be able to interact with Docker.
Desktop
Browse to https://docs.docker.com/desktop/install/ubuntu/ and press the button. This will download a file with a .deb extension. For example, docker-desktop-4.30.0-amd64.deb.
In a terminal change to the directory containing the .deb file. Then install.
sudo apt-get install ./docker-desktop-4.30.0-amd64.deb
You should then be able to run the Docker application via your desktop.
Test
Pull the hello-world image.
docker pull hello-world
Run the hello-world image.
docker run hello-world
You should see the following output on the terminal:
Hello from Docker!
This message shows that your installation appears to be working correctly.
To generate this message, Docker took the following steps:
1. The Docker client contacted the Docker daemon.
2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
(amd64)
3. The Docker daemon created a new container from that image which runs the
executable that produces the output you are currently reading.
4. The Docker daemon streamed that output to the Docker client, which sent it
to your terminal.
To try something more ambitious, you can run an Ubuntu container with:
$ docker run -it ubuntu bash
Share images, automate workflows, and more with a free Docker ID:
https://hub.docker.com/
For more examples and ideas, visit:
https://docs.docker.com/get-started/
Other Installs
You’ll need a text editor for writing a Dockerfile. Either use an existing editor or install one. Visual Studio Code is a good option.