[Libguestfs] cloud-init in virt-builder images

I've noticed that none of the images from virt-builder have cloud-init in them by default.  The documentation reads to me as if the OS vendor's official cloud images are the ones used as the sources for the generated images but I'm assuming this is wrong. I know for a fact CentOS's cloud images from https://cloud.centos.org/centos/7/images/ and Ubuntu's from https://cloud-images.ubuntu.com/bionic/ have cloud-init installed and enabled already. Where are the images sourced from if not these official images? I understand I can install cloud-init with virt-builder but I'm trying to figure out what OS-distributed images are in use so I may determine what else is different from expectations. -- Jonathan Wright KnownHost, LLC https://www.knownhost.com