...
As part of this feature, the VM's Bootstrap script tab is now available in private cloud for cloud-init use only. Configuration drive is hypervisor agnostic and support for the bootstrap script depends on the configuration of cloud-init or another system on the VM template. However, cloud-init can also run other types of scripts, such as bash scripts.
Bootstrap with configuration drive in private cloud
See also Add VM bootstrap script and Add VM a bootstrap script to a VM template Include Page