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
On Debian/Ubuntu installs of RPM, /usr/lib/rpm/macros sets
%_dbpath %(echo $HOME/.rpmdb)
which makes quite a bit of sense, because RPM is not the system
packager and thus RPM is setup to install things into a hierarchy in
the users homedir.
However, this messes things up when building a Fedora chroot on an
Ubuntu platform.
We use RPM & yum from the base-system to bootstrap the Fedora chroot.
While both obey --root flags, they still pick up the %_dbpath macro
and so end up creating the RPM database in <chroot>/home/user/.rpmdb
After we have bootstrapped yum/dnf, we execute further installation
commands from inside the chroot -- where we now have the Fedora
version of /usr/lib/rpm/macros and hence have _dbpath set to
/var/lib/rpm -- except there is no rpm database there.
Should anyone be finding this in the future, the actual issue that
appears is
$ sudo chroot /opt/dib_tmp/image.b6B5S3f6/mnt dnf makecache
Error: Failed to synchronize cache for repo 'fedora' from \
'https://mirrors.fedoraproject.org/metalink?repo=fedora-$releasever&arch=x86_64': \
Cannot prepare internal mirrorlist: file "repomd.xml" was not found in metalink
Note the issue there is that $releasever is not expanded, because the
rpmdb where this info is kept is not populated.
The trick is to make sure we override this value when using the host
rpm/yum to setup the chroot. The bare rpm calls, which we use to
install the repos, have a --dbpath argument where we can override
this. yum does not however, so we override this in the global
~/.rpmmacros while we are installing the packaging tools and
dependencies into the chroot.
Copious comments are included, because this is super-confusing.
Change-Id: I20801150ea02d1c64f118eb969fb2aec473476f7
fedora-minimal fails to build on Ubuntu Trusty due do being unable to
find the initrd (see Id4c04d7ae20068643df34d2fa31068e8a917a52d).
This is a rather obscure problem that comes from the intersection of
several things.
The first thing to note is that the post-install scripts of the
kernel-core package use kernel-install [1]. For whatever reason, this
installs the kernel to /boot/MACHINE-ID/KERNEL-VERSION
MACHINE-ID comes from /etc/machine-id; a UUID that should have been
created by the systemd post-inst scripts with systemd-machine-id-setup
[2].
The chroot environment provided for root.d elements has no kernel
file-systems like /proc or /dev mounted. This is where differences in
the base-system come into play -- on more recent systems that
implement getrandom() systemd does not need /dev/urandom to generate
the machine-id [3]; we get a value and /etc/machine-id is populated.
On older platforms (Trusty), systemd-machine-id-setup fails (unable to
access /dev/urandom) and we end up with a blank /etc/machine-id. This
ends up making kernel-install (the script) fail during yum's
installation of kernel-core, which means the initrd is not installed
correctly.
We end up bailing out in fedora-minimal/install.d/99-ramdisk, where we
try to put the installed ramdisk in /boot for the later grub install
scripts to find.
The solution here is to mount the standard kernel file-systems within
the chroot before we try installing.
[1] http://www.freedesktop.org/software/systemd/man/kernel-install.html
[2] http://www.freedesktop.org/software/systemd/man/systemd-machine-id-setup.html
[3] https://github.com/systemd/systemd/blob/master/src/basic/random-util.c
Change-Id: Ibcce35da928f64e6a719b070bcc833346ee7ee92
yum-minimal/root.d/08-yum-chroot runs before yum/root.d/50-yum-cache,
and thus if run on a completely fresh system will fail in
08-yum-chroot as the YUM_CACHE directory isn't made.
This is probably hidden by testing & nodepool builds, because it sets
DIB_IMAGE_CACHE. It was hidden from me because locally I have done
builds using the "yum" element previously, which had created the
cache.
Change-Id: I333f5f7e67d198f75a522cc296c118c2e94a5ecb
I'm not sure why we try to do an extra install of these, it is done
inside the chroot in _install_repos. Currently it just gets skipped
saying the packages are already installed.
Change-Id: Ic7aa8cbe13e4347b447e84bb9c12483a4e125228
Add basic F22/dnf support to yum-minimal path. We extract common
code, add some comments and reduce duplication.
Change-Id: If4bd5f88e26bd6f2168958f1ec1efff1072de7ba
Move yum-based install into a function, to make way for a second
related function where use dnf later
Change-Id: Iad09f3753ecdfa0c10cb8a0970a3c8e5a2dccab1
fedora-release >= 22 has acquired a dependency on /bin/sh. This comes
from a %posttrans section of the spec file, which is symlinking the
os-release file.
As discussed in [1], the links are setup correctly in the rpm, so the
post-install script isn't doing anything. Thus we can safely ignore
the dependency with --nodeps
[1] https://bugzilla.redhat.com/show_bug.cgi?id=1265873
Change-Id: Icf17c84580a75d42d8e90d5d6e81ae7f5f576c32
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
