This container can be pulled via:
  docker pull registry.opensuse.org/filesystems/ceph/octopus/images/ceph/prometheus-server:2.27.1
  docker pull registry.opensuse.org/filesystems/ceph/octopus/images/ceph/prometheus-server:2.27.1.7.2
  docker pull registry.opensuse.org/filesystems/ceph/octopus/images/ceph/prometheus-server:latest
  docker pull registry.opensuse.org/filesystems/ceph/octopus/images/ceph/prometheus-server:leap15.2

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.