[Request] Support LiveCD creation with dracut

[disjustin]

Is your feature request related to a problem? Please describe.

I'm trying to create a LiveCD with a preset root partition size and automated root login. Both of which I have not been able to implement fully yet per the noted roadblocks:

• Booting with boot=casper creates a predefined password-less live user during boot and disables the root user at the login prompt
• After running sudo su, the root partition is empty and missing the startup .bash* files that I attempted to provide.

Describe the solution you'd like

A network bootable Ubuntu LiveCD that'll boot directly into the root user terminal with a user-defined root partition size.

Describe alternatives you've considered

Dracut is the alternative, and a long-awaited one

Additional context

• canonical-releases-ubuntu-25-04-plucky-puffin
• dracut-will-be-supported-in-ubuntu-25-04