This container can be pulled via:
  docker pull registry.opensuse.org/home/nbelouin/gittry/images/metallb-speaker:v0.14.8
  docker pull registry.opensuse.org/home/nbelouin/gittry/images/metallb-speaker:v0.14.8-1.3

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.