Taken from pimylifeup

Install Docker

To install Docker on a raspberry pi, we need the following commands:

Firstly, keep system up-to-date:

sudo apt update
sudo apt upgrade

Then execute the Docker installation script:

curl -sSL https://get.docker.com | sh

Then, allow pi (OR WHATEVER YOUR DEFAULT USER IS) to the docker group:

sudo usermod -aG docker pi

Finally, logout and log back in to allow changes to take place.

Test-drive installation

Check that docker shows up amongst the user groups:

groups | grep docker

Try out the hello world of Docker apps:

docker run hello-world