This container can be pulled via:
  docker pull registry.opensuse.org/home/juliogonzalezgil/branches/systemsmanagement/uyuni/master/stable/containers/uyuni/proxy-tftpd:5.2
  docker pull registry.opensuse.org/home/juliogonzalezgil/branches/systemsmanagement/uyuni/master/stable/containers/uyuni/proxy-tftpd:5.2.4.2.uyuni1
  docker pull registry.opensuse.org/home/juliogonzalezgil/branches/systemsmanagement/uyuni/master/stable/containers/uyuni/proxy-tftpd:beta
  docker pull registry.opensuse.org/home/juliogonzalezgil/branches/systemsmanagement/uyuni/master/stable/containers/uyuni/proxy-tftpd:latest

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.