We are working on it for one 4.14. Right now you need to do this manually:
1.- Create VM and customize it
2.- Save the target disks back to the snapshots (or alternatively shutdown
the VM if not needed)
3.- Set image as non-persistent
4.- Create a template using the image
5.- Create new virtual machines using this new template
I have a ruby script which can generate a template from a VM. It’s intended to capture changes that were made to a running VM. (e.g. hot-added disks/network adapters). I’ll see what I can do about getting it open-sourced.