dracut-ubuntu-core

This is an early experiment for using dracut instead of core-initrd to generate an initramfs for Ubuntu Core.

Here are the steps to build that initramfs. On a machine/container/chroot with matching version of Ubuntu than the target Ubuntu Core version:

• Build this dracut-ubuntu-core .deb package and install it
• Install zstd sbsigntool xdelta3
• Get PkKek-1-snakeoil.{key,pem} from core-initrd or your own keys
• Run build-initrd.sh or manually run the commands
• This will have created a snap of pc-kernel
• Build an image with ubuntu-image using that snap

To simplify this process build-in-lxc.sh will create a container and run all the commands.

It is also possible to run Snapcraft to build the pc-kernel snap. Since core22 has no LXD or multipass backend yet in Snapcraft, build-snap.sh is provided to run snapcraft in LXD.