Refer to the official documentation: https://docs.docker.com/install/linux/docker-ce/ubuntu/#install-using-the-repository
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
sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu zesty stable"
sudo apt-get update
sudo apt-get install docker-ce