Installing Docker on Linux

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 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.