pi-ansible/roles/docker/templates/daemon.json.j2

{
  "data-root": "{{ ssd_mount_point }}/docker-runtime",
  "default-address-pools": [
    {
      "base": "172.17.0.0/16",
      "size": 24
    }
  ],
  "ipv6": true,
  "fixed-cidr-v6": "fd00::/80"
}