add missing libelf dependency to kernel-module-injector image

[kvaps]

this PR fixes problem of compiling DRBD module on Rocky Linux 9 more details: https://github.com/deckhouse/deckhouse/issues/2268

[kvaps]

Which is the Dockerfie used by piraeus-operator by default? I would like to update just this, because having libelf-dev makes it working on Rocky Linux 9 as well.

[WanzenBug]

I guess for Piraeus, which uses the Compile method by default, we really could have just a single image. I believe as long as the GCC version is modern enough to support all compile options on modern kernels we should be good.

But that's just speculation. KBuild will issue a warning if you use a different compiler when building the kmod compared to the kernel, and I assume that warning exists for a reason.

[kvaps]

Can't we just put a few compilers into the image? Or even better: try using gcc from the host namespace. User needs to install kernel-headers anyway, installing gcc shouldn't be a big deal though.

ref to the discussion about the warning https://patchwork.kernel.org/project/linux-kbuild/patch/[email protected]/