Please note that as of 7/2019 docker is broken in Raspian Buster. Until the issue is fixed, Raspian Stretch should be used.
1. Install Raspbian Stretch, enable ssh, and change default password.
2. From a bash terminal, type:
wget https://raw.githubusercontent.com/scverhagen/solarpigardener/production/deploy/deploy.sh
chmod +x ./deploy.sh
sudo deploy.sh
sudo reboot
The script will install Docker, docker-compose, solarpigardener and watchtower (for automatic updates).