"Sysprep" for Linux after cloning VMs?

Solution 1:

That's exactly what virt-sysprep is for.

From the man page:

Virt-sysprep can reset or unconfigure a virtual machine so that clones can be made from it. Steps in this process include removing SSH host keys, removing persistent network MAC configuration, and removing user accounts. Virt-sysprep can also customize a virtual machine, for instance by adding SSH keys, users or logos. Each step can be enabled or disabled as required.

You can use virt-sysprep on any disk image format that your version of qemu understands. This usually includes raw disk images, qcow2, VMware VMDK, Windows VHD, VirtualBox VDI, and many others.