Re: [Libguestfs] [p2v PATCH 2/4] make-disk: restrict kernel update bug work-around

Commit 2764abefaa14 ("make-disk: Don't upgrade the kernel to avoid kernel command line bug", 2022-03-24) replaced the "--update" option of virt-builder with an open-coded DNF update command, excluding the kernel packages from the update. Albeit a justified workaround, it is a bit too broad: it breaks on all guest OS images that don't have DNF, such as old RHEL, Debian and Ubuntu, etc. (In a subsequent patch, I'm going to refactor the Debian/Ubuntu branch, and for testing that, I first need eliminate the open-coded DNF command.) Refine the workaround as follows: - I've tested Fedora 33 and Fedora 37; they work without the workaround (they are not yet, and no longer, affected by the bug, respectively). - I've tested Fedora 34 and 36, they are affected. They need the workaround. - Fedora 35 is also broken, per <https://bugzilla.redhat.com/show_bug.cgi?id=1945835#c24>;. - RHEL-9.0 and RHEL-9.1 *seem* to work fine without the workaround (that is, with commit 2764abefaa14 reverted). However, that's deceptive: in my testing, the original "--update" option does not bring in any new kernel packages, so even if the bug is still there, it is not triggered. Because RHEL-9 is based on Fedora 34, which is affected, assume that RHEL-9 is affected too. Signed-off-by: Laszlo Ersek <lersek(a)redhat.com&gt; --- virt-p2v-make-disk.in | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/virt-p2v-make-disk.in b/virt-p2v-make-disk.in index 865a92847f8b..44ff0b45ac7a 100644 --- a/virt-p2v-make-disk.in +++ b/virt-p2v-make-disk.in @@ -48,6 +48,7 @@ eval set -- "$TEMP" output= upload= verbose= +declare -a update_option=(--update) declare -a passthru usage () @@ -184,6 +185,19 @@ EOF --upload $tmpdir/p2v.conf:/etc/dracut.conf.d/ --run $tmpdir/post-install " + # Fedora 34 through 36, and presumably RHEL-9 (based on Fedora 34) + # suffer from a bug where a kernel image installation via libguestfs + # pollutes the just installed kernel's commandline in the boot loader + # config file. Irrelevant and bogus parameters from the appliance + # kernel's /proc/cmdline are copied over. This prevents the root + # filesystem from being mounted. Refer to + # <https://bugzilla.redhat.com/show_bug.cgi?id=1945835#c24> and/or + # commit 2764abefaa14. + case "$osversion" in + fedora-34|fedora-35|fedora-36|rhel-9.*) + update_option=(--run-command 'dnf -y update --exclude=kernel\*') + ;; + esac ;; debian-*|ubuntu-*) depsfile="$datadir/dependencies.debian" @@ -246,7 +260,7 @@ virt-builder "$osversion" \ $preinstall_args \ --hostname p2v.local \ --run-command 'hostname p2v.local' \ - --run-command 'dnf -y update --exclude=kernel\*' \ + "${update_option[@]}" \ --install "$install" \ --root-password password:p2v \ --upload "$datadir"/issue:/etc/issue \