[Libguestfs] virt-builder fails in fedora 34 container:

[Richard W.M. Jones]

On Sat, Jun 12, 2021 at 11:11:22PM +0300, Nir Soffer wrote:
> I'm running this inside a fedora 34 container in ovirt-imageio CI:
> 
>     'virt-builder', '-v', '-x', 'cirros-0.3.5', '--write',
> '/etc/cirros-init/config:DATASOURCE_LIST="nocloud"',
> '--root-password', 'password:', '-o',
> '/var/tmp/imageio-images/cirros-0.3.5'
> 
> The command fails in:
> 
> supermin: ext2: copying kernel modules
> supermin: ext2: creating minimal initrd
> '/var/tmp/.guestfs-0/appliance.d.t7nny0l7/initrd'
> supermin: exception:
> Sys_error("/lib/modules/5.12.9-300.fc34.x86_64/modules.dep: No such
> file or directory")

We use this file in order to construct the minimal initrd with some
virtio modules, which is sufficient to bring up the supermin root
filesystem.  The file itself is used to calculate the correct set of
module dependencies (so that, for example, if a virtio kmod needs
another kmod then the other kmod will be pulled in).  See:

https://github.com/libguestfs/supermin/blob/c89e4923909ef84541ac1c047bf64d13b1595b4f/src/format_ext2_initrd.ml

I believe in Fedora the file is created via a %post script in
kernel-core which runs /bin/kernel-install (from systemd-udev).  This
in turn is a shell script which runs snippets from
/etc/kernel/install.d and /usr/lib/kernel/install.d which are supplied
from all kinds of other packages.  On my machine one of these is
/usr/lib/kernel/install.d/50-depmod.install (also from systemd-udev)
which eventually runs depmod -a which creates this file.

So those are some of the packages which might be missing.  Does
modules.dep get created anywhere inside the container?  It's possible
it moved.

It's also possible to set the environment variable KERNEL_INSTALL_VERBOSE=1
which should show (in the dnf install output I guess?) if/when the
depmod command runs.

> I think I'm missing some package removed from the fedora 34 container,
> but I don't have
> any idea which one.
> 
> I hope someone has more insight on this.

It's curious that things have changed since F33.  Could you build
containers for both and diff the list of package names?  Maybe a
dependency is missing or has become a soft dep.

rpm -qa --qf '%{name}\n' | sort

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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