This container can be pulled via:
  docker pull registry.opensuse.org/opensuse/bci/spack:0.21
  docker pull registry.opensuse.org/opensuse/bci/spack:0.21-8.2
  docker pull registry.opensuse.org/opensuse/bci/spack:0.21.2
  docker pull registry.opensuse.org/opensuse/bci/spack:0.21.2-8.2
  docker pull registry.opensuse.org/opensuse/bci/spack:latest

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.