Re: [PATCH v2] kbuild: use hostname -s along uname to obtain LINUX_COMPILE_HOST

From: Nathan Chancellor
Date: Fri Apr 01 2022 - 13:21:14 EST

Hi Francesco,

On Fri, Apr 01, 2022 at 05:17:06PM +0200, FraSharp wrote:
> * On some systems (e.g. macOS, Debian, Fedora), using commands like 'uname -n' or
> 'hostname' will print something similar to "hostname.domain"
> ("" for example), which is very annoying.
> What works instead is 'hostname -s', which will only write hostname
> without the domain ("Francescos-Air" for example),
> but also keep 'uname -n', as some systems as Arch Linux does not have
> 'hostname' as command.
> * This commit is complementary to
> 1e66d50ad3a1dbf0169b14d502be59a4b1213149
> ("kbuild: Use uname for LINUX_COMPILE_HOST detection")
> Signed-off-by: Francesco Duca <s23265@xxxxxxxx>
> ---
> scripts/mkcompile_h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
> diff --git a/scripts/mkcompile_h b/scripts/mkcompile_h
> index ca40a5258..3eefbafe5 100755
> --- a/scripts/mkcompile_h
> +++ b/scripts/mkcompile_h
> @@ -34,7 +34,7 @@ else
> fi
> if test -z "$KBUILD_BUILD_HOST"; then
> - LINUX_COMPILE_HOST=`uname -n`
> + LINUX_COMPILE_HOST=$(hostname -s 2>/dev/null || uname -n)
> else
> fi
> --
> 2.32.0 (Apple Git-132)

I personally think this is going to output something objectively worse
for my use case. I use containers for my main workflow, which have a
hostname of "container name" and domain name of "host's hostname".

For example:

$ uname -n

$ distrobox enter dev-arch

$ uname -n

With the move to 'hostname -s' by default, I lose the information about
the main host machine, so I am unable to tell exactly which container
built the image:

$ hostname -s

While moving to containers is supposed to help eliminate the need to
know about a particular machine because it should be the same
environment, it is still relevant because I build certain tools on some
machines and not others and I am not necessarily updating each container
on the same timeline, so it is still useful to have this information
included in the kernel image for tracking purposes.

Given this is a purely a subjective/cosmetic issue, why can you not just
add something like

export KBUILD_BUILD_HOST=$(hostname -s)

in your shell's start up file, so that the hostname is in the format
that you desire?