This container can be pulled via:
  docker pull registry.opensuse.org/opensuse/factory/totest/containers/opensuse/squid:7.7
  docker pull registry.opensuse.org/opensuse/factory/totest/containers/opensuse/squid:7.7-4.389
  docker pull registry.opensuse.org/opensuse/factory/totest/containers/opensuse/squid:latest

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.