Support Kernel Build System (Debian 11)

[kvaps]

Debian 11 installs the linux-kbuild as dependency to kernel-headers package.

The tools and Makefile from it are used directly by entry.sh script of kernel-module-injector

The problem is that most of files from this package are located under /usr/lib directory which we can't directly passtrough into container, because bash and other libs inside the container are using them.

We can't also passtrough the /usr/lib/linux-kbuild-5.10 directory as the name is unpredictable for it and depending only on kernel version.

Solution: pass it trough under /host/usr/lib directory and setup symlinks for non-existing paths into /usr/lib of the container

[WanzenBug]

Just last week we added linux-kbuild-* in the debian containers: piraeusdatastore/piraeus#145

From my tests this seems to be enough to fix building with the existing Operator on Debian.

[kvaps]

Okay then this PR is up for consideration

I was just thinking if there are no other cases like that, when kernel-headers demands on anything from /usr/lib?
If not, we can limit pattern to symlink only them /usr/lib/linux-kbuild-*

Another question: Is it correct way to install linux-kbuild-* from debian and ship it with the docker image? What if Ubuntu will go the same way by separating kbuild files from kernel-headers, then we will use debian tools to compile ubuntu's kernel-headers, can we be sure that it will work in that way?

[WanzenBug]

I was just thinking if there are no other cases like that, when kernel-headers demands on anything from /usr/lib?

For now, Debian seem to be the only ones doing this micro-packaging, in all other cases /usr/src and /lib/modules was enough

Another question: Is it correct way to install linux-kbuild-* from debian and ship it with the docker image?

If we use the debian image to build, we need to have the debian linux-kbuild-* tools. The tools depend on shared libraries, and those need to be available in the container.

If Ubuntu decided they also want to do this split with linux-kbuild-*, and we would link those from the host, I think this would break. Because the tools try to load some shared libraries that don't exist in a Debian container. Luckily, if Ubuntu switches, we would use our Ubuntu containers in any case.