rootfs contains all initramfs dependencies and tools

[Oliver Grawert]

in the snappy world we do not create or update the initrd on the fly so neither the dependencies of initramfs-tools nor the scripts themselves are required to be installed inside the rootfs.

due to the nature of our build process initramfs-tools and initramfs-tools-ubuntu-core get installed in the rootfs chroot before the chroot gets turned into a tarball. instead of doing it this way, initramfs-tools and all its dependencies should only be installed after tarball creation to run update-initramfs and create the initrd.img.
this way we would not have any of the dependencies inside the rootfs tarball.
implementing this setup will likely require some changes to seed management or the bootstrap process to not pull in initramfs-tools in the first place and additionally some scripting in the live-build/auto/build script in livecd-rootfs for the post processing and initrd generation.

[Alexander Sack (asac)]

I suspect we might want to separate building kernal and building OS snap; I guess initramfs would be built as part of kernel snap. at best we would have a snapcraft plugin to build kernels and initrd and put them into a snap.

Michael?

[Mark Shuttleworth (sabdfl)]

Yes, initrd is clearly a function of the kernel snap not gadget / os snap.

Mark

[Oliver Grawert (ogra)]

for the phone we create a generic initrd.img directly from the initramfs-tools-ubuntu-touch source package, since the initramfs-tools-ubuntu-core package is directly based on the phone package just moving over the build scripts would be easy enough ... this would completely decouple the rootfs from the initrd (dropping the historically grown initramfs-tools package installation inside the rootfs will be a bit more work but bring a massive gain in rootfs size i guess)