features: Expose KernelVersion function

[brycekahle]

No description provided.

[lmb]

There is a lint failure: https://ebpf.semaphoreci.com/jobs/b3859009-9587-4599-8d94-c01addc57277#L543

[brycekahle]

@lmb the CI seems to be stuck on the 5.10 build

[ti-mo]

Could we change the function doc to the below?

// KernelVersion returns the version of the currently running kernel.
//
// The kernel version and patch level are represented as a single value
// equal to the KERNEL_VERSION macro from linux/version.h.

And please squash and prefix your commit message with features: as it's useful to know it landed in the features package from looking at the commit log. :)

Thanks!

(I think you have enable pushes from maintainers turned off)

[ti-mo]

@brycekahle Just curious, but what is this going to be used for in practice? Wouldn't you prefer more feature probes being exposed over a version number? I think we (and you) have established it's essentially meaningless with the backporting going on in RHEL and friends, so this is adding a footgun. If we do decide to add it, it should come with warning bells. 🙂

[brycekahle]

@ti-mo So we need this for a very specific reason. We are working on a feature to automatically download kernel headers. In order to validate that we have the correct headers to match the running kernel, we need to know what the LINUX_VERSION_CODE of the running kernel is, so we can compare it to the one from the header file.

[ti-mo]

Superseded by #585.