https://docs.docker.com/engine/installation/linux/ubuntulinux/
https://docs.docker.com/engine/getstarted/step_one/#step-1-get-docker
https://docs.docker.com/engine/installation/
echo "deb https://apt.dockerproject.org/repo ubuntu-trusty main" | sudo tee /etc/apt/sources.list.d/docker.list
sudo apt-get update
| Precise 12.04 (LTS) | deb https://apt.dockerproject.org/repo ubuntu-precise main |
| Trusty 14.04 (LTS) | deb https://apt.dockerproject.org/repo ubuntu-trusty main |
| Wily 15.10 | deb https://apt.dockerproject.org/repo ubuntu-wily main |
| Xenial 16.04 (LTS) | deb https://apt.dockerproject.org/repo ubuntu-xenial main |