As of 20/10/2017, a release file for Ubuntu 17.10 Artful Aardvark is not available on Download Docker.
sudo apt-get update
sudo apt-get install apt-transport-https ca-certificates curl software-properties-common
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
sudo apt-key fingerprint 0EBFCD88