This container can be pulled via:
  docker pull registry.opensuse.org/home/moio/uyuni/master/containers/containers/uyuni/proxy-salt-broker:4.3.10
  docker pull registry.opensuse.org/home/moio/uyuni/master/containers/containers/uyuni/proxy-salt-broker:4.3.10.23.27.uyuni1
  docker pull registry.opensuse.org/home/moio/uyuni/master/containers/containers/uyuni/proxy-salt-broker:beta
  docker pull registry.opensuse.org/home/moio/uyuni/master/containers/containers/uyuni/proxy-salt-broker:latest

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.