This container can be pulled via:
  docker pull registry.opensuse.org/opensuse/factory/arm/totest/containers/opensuse/squid:5.6
  docker pull registry.opensuse.org/opensuse/factory/arm/totest/containers/opensuse/squid:5.6-3.1247
  docker pull registry.opensuse.org/opensuse/factory/arm/totest/containers/opensuse/squid:latest

Set DOCKER_CONTENT_TRUST=1 to enable image tag verification.