diskimage-builder/elements/fedora-minimal
Ian Wienand 1d476dd994 Remove fedora-minimal/install.d/99-ramdisk
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
2015-11-19 21:03:45 +11:00
..
environment.d Update default fedora-minimal to f22 2015-10-14 06:36:06 +11:00
yum.repos.d Add a yum-minimal element that just uses yum 2015-04-14 13:39:18 -04:00
element-deps Add a yum-minimal element that just uses yum 2015-04-14 13:39:18 -04:00
element-provides Add a yum-minimal element that just uses yum 2015-04-14 13:39:18 -04:00
README.rst Add a yum-minimal element that just uses yum 2015-04-14 13:39:18 -04:00

==============
fedora-minimal
==============
Create a minimal image based on Fedora.

Use of this element will require 'yum' and 'yum-utils' to be installed on
Ubuntu and Debian. Nothing additional is needed on Fedora or CentOS. The
element will need `python-lzma` everywhere.

Due to a bug in the released version of urlgrabber, on many systems an
installation of urlgrabber from git is required. The git repository
can be found here: http://yum.baseurl.org/gitweb?p=urlgrabber.git;a=summary

The `DIB_OFFLINE` or more specific `DIB_YUMCHROOT_USE_CACHE`
variables can be set to prefer the use of a pre-cached root filesystem
tarball.

This element sets the `DIB_RELEASE` var to 'fedora'. The release of fedora
to be installed can be controlled through the `DIB_RELEASE` variable, which
defaults to '21'.