set up kernel crashkernel for osbuild in kernel hook
Resolves: bz1895258
Resolves: bz2024976
Upstream: Fedora
Conflict: None
commit ddd428a1d0d72bee2a8459b1a81541bcd0676873
Author: Coiby Xu <coxu@redhat.com>
Date: Wed Dec 15 21:45:18 2021 +0800
set up kernel crashkernel for osbuild in kernel hook
osbuild is a tool to build OS images. It uses bwrap to install packages
inside a sandbox/container. Since the kernel package recommends
kexec-tools which in turn recommends grubby, the installation order would
be grubby -> kexec-tools -> kernel. So we can use the kernel hook
92-crashkernel.install provided by kexec-tools to set up kernel
crashkernel for the target OS image. But in osbuild's case, there is no
current running kernel and running `uname -r` in the container/sandbox
actually returns the host kernel release. To set up kernel crashkernel for
the OS image built by osbuild, a different logic is needed.
We will check if kernel hook is running inside the osbuild container
then set up kernel crashkernel only if osbuild hasn't specified a
custome value. osbuild exposes [1] the container=bwrap-osbuild environment
variable. According to [2], the environment variable is not inherited down
the process tree, so we need to check /proc/1/environ to detect this
environment variable to tell if the kernel hook is running inside a
bwrap-osbuild container. After that we need to know if osbuild wants to use
custom crashkernel value. This is done by checking if /etc/kernel/cmdline
has crashkernel set [3]. /etc/kernel/cmdline is written before packages
are installed.
[1] https://github.com/osbuild/osbuild/pull/926
[2] https://systemd.io/CONTAINER_INTERFACE/
[3] https://bugzilla.redhat.com/show_bug.cgi?id=2024976#c5
Reviewed-by: Pingfan Liu <piliu@redhat.com>
Reviewed-by: Philipp Rudo <prudo@redhat.com>
Signed-off-by: Coiby Xu <coxu@redhat.com>
Signed-off-by: Coiby Xu <coxu@redhat.com>
