When the kernel gets installed on Fedora, the rpm post scripts call
"/bin/kernel-install" [1] to install it. This is a script provided by
systemd.
However, in [2], Fedora ships a patch to kernel-install that makes a
call-out to /sbin/new-kernel-pkg -- the install script provided by
grubby [3]
Without grubby installed, systemd's kernel-install script goes off and
runs dracut plugins directly [4], which eventually creates the initrd.
For reasons that are not clearly explained, the initrd will end up in
a a "machine-id" sub-directory of /boot (possibly, so you can symlink
it?). It is also called "initrd", even though it's an initramfs, for
historical reasons in dracut I think.
It is at this point that I think 99-ramdisk has been written to move
the generated initrd file back into /boot. Later on, when we build
the image, we run grub-install and it picks up the kernel and the
initrd and installs everything.
grubby's new-kernel-pkg [6] it's very similar -- it uses dracut to
make the initramfs ... but in this case it is put in /boot and is
actually called initramfs.
The subtle change that led me down this path is that dracut has been
modified to have a "Recommends" for grubby for >F22 [7]. After
discussing this change with the author, it turns out it was *always*
intended to use the grubby-based kernel install scripts for Fedora --
our builds have been incorrect in not including the package. The
author got sick of people removing the package and making unbootable
systems, hence the change.
Thus this removes the workarounds in 99-ramdisk and replace it with an
install of the grubby package. grubby's kernel install script will
put the kernel & generated initramfs in /boot, and it will be
installed correctly via the usual grub install later when we build the
disk image.
I have built F22 & F23 fedora-minimal images with this and they boot.
[1] http://pkgs.fedoraproject.org/cgit/kernel.git/tree/kernel.spec#n1832
[2] http://pkgs.fedoraproject.org/cgit/systemd.git/tree/kernel-install-grubby.patch
[3] http://linux.die.net/man/8/new-kernel-pkg
[4] https://github.com/haraldh/dracut/blob/master/50-dracut.install
[5] 81516adcb7
[6] https://github.com/rhinstaller/grubby/blob/master/new-kernel-pkg
[7] 47ff68e78b
Change-Id: I1a6e45d04755515286b3d49f8280c16b527e2f48
The centos-minimal approach of using rinse does not, it turns out, work
on centos. That's a bummer. It's also rather heavyweight. Instead, with
minor machinations, we can just use yum itself pointed at a chroot.
Also adding fedora-minimal element which creates a fedora image using
the new yum-minimal approach.
Co-Authored-By: Gregory Haynes <greg@greghaynes.net>
Change-Id: I026fd9d323e786dae5bb67824c6501067e1ceaa3
