cat /etc/issue
Raspbian GNU/Linux 9 \n \l
 
apt-get install \
    apt-transport-https \
    ca-certificates \
    curl \
    gnupg2 \
    software-properties-common
 
curl -fsSL https://download.docker.com/linux/debian/gpg | sudo apt-key add -
 
cat /etc/apt/sources.list.d/docker.list
deb [arch=armhf] https://download.docker.com/linux/debian      stretch stable
 
apt-get update
apt-get install --yes docker-ce