deb {apt_cdn}/debian {release} main contrib non-free
deb {apt_cdn}/debian {release}-backports main
deb {apt_cdn}/debian-security {release}/updates main contrib non-free

deb http://packages.cloud.google.com/apt cloud-sdk-{release} main
deb http://packages.cloud.google.com/apt google-cloud-packages-archive-keyring-{release} main
deb http://packages.cloud.google.com/apt google-cloud-compute-{release} main