Comment 5 for bug 1672436

I would personally also opt for a generic hook mechanism. For now we could only concentrate on the hook that would be executed after the rootfs is ready to enable copying/deleting arbitrary files on the filesystem, but the extensible mechanism we could use later on when the need for other hooks arises. I don't think there would be much difference time-wise on doing it one way or another as both solutions require some design and code rewrites.