Yes, for now both will continue to exist. The download.docker.com/linux/ubuntu repo is the preferred method of installing docker-ce on ubuntu. Instructions here

Yes, for now both will continue to exist. The download.docker.com/linux/ubuntu repo is the preferred method of installing docker-ce on ubuntu. Instructions here: https://docs.docker.com/engine/installation/linux/ubuntu/#install-docker https://docs.docker.com/engine/installation/linux/ubuntu/#in... In the future we will phase out the apt.dockerproject.org repo.