This container can be pulled via:
  docker pull registry.opensuse.org/devel/unifiedcore/dev/containers/rancher/elemental-channel/sl-micro:6.1-base
  docker pull registry.opensuse.org/devel/unifiedcore/dev/containers/rancher/elemental-channel/sl-micro:6.1-base-2.1

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.