This container can be pulled via:
  docker pull registry.opensuse.org/opensuse/samba:4.21
  docker pull registry.opensuse.org/opensuse/samba:4.21.1
  docker pull registry.opensuse.org/opensuse/samba:4.21.1-5.270
  docker pull registry.opensuse.org/opensuse/samba:latest

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.