This container can be pulled via:
  docker pull registry.opensuse.org/isv/rancher/elemental/pr/rancher/elemental/pr-1404/containers/suse/sl-micro/6.0/rt-os-container:2.1.0
  docker pull registry.opensuse.org/isv/rancher/elemental/pr/rancher/elemental/pr-1404/containers/suse/sl-micro/6.0/rt-os-container:2.1.0-64.9
  docker pull registry.opensuse.org/isv/rancher/elemental/pr/rancher/elemental/pr-1404/containers/suse/sl-micro/6.0/rt-os-container:latest

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.