This container can be pulled via:
  docker pull registry.opensuse.org/virtualization/containers/images/opensuse-tumbleweed/container_zsystems/opensuse/tumbleweed:20190328
  docker pull registry.opensuse.org/virtualization/containers/images/opensuse-tumbleweed/container_zsystems/opensuse/tumbleweed:20190328.29.21
  docker pull registry.opensuse.org/virtualization/containers/images/opensuse-tumbleweed/container_zsystems/opensuse/tumbleweed:latest

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.