Yet another from scratch guide
deb [arch=amd64] https://apt.dockerproject.org/repo ubuntu-xenial main
deb [arch=amd64] http://ppa.launchpad.net/k8s/ppa/ubuntu xenial main
get keys
apt-key adv --keyserver hkp://keyserver.ubuntu.com --recv-keys F76221572C52609D
apt-key adv --keyserver hkp://keyserver.ubuntu.com --recv-keys 738C1654E1DEBDE4