Re: [PATCH] glibc: move ld.so.conf back to main package

["Andreas Oberritter" <obi@opendreambox.org>]

On Mon, 18 May 2020 15:25:19 +0200
Rasmus Villemoes <rasmus.villemoes@prevas.dk> wrote:

> On 18/05/2020 14.29, Andreas Oberritter wrote:
> > Hello Rasmus,
> > 
> > On Mon, 18 May 2020 14:12:43 +0200
> > Rasmus Villemoes <rasmus.villemoes@prevas.dk> wrote:
> > 
> >> I'm certainly open to other ways of solving this. But can we agree that
> >> it is a bug that the ldconfig done at build-time does not take
> >> /etc/ld.so.conf.d/* into account, and that that should not depend on
> >> whether one has ldconfig-the-binary on target?
> > 
> > have you tried installing ldconfig and adding it to ROOTFS_RO_UNNEEDED? It might be an improvement to include it in ROOTFS_RO_UNNEEDED by default.
> 
> Thanks, but I don't think that will work:
> 
>         self._uninstall_unneeded()
> 
>         if self.progress_reporter:
>             self.progress_reporter.next_stage()
> 
>         self._insert_feed_uris()
> 
>         self._run_ldconfig()
> 
> so if the ldconfig package (including the ld.so.conf file) is just added
> to ROOTFS_RO_UNNEEDED, it will be gone by the time we get to doing the
> build-time ld.so.cache generation. And I think it has to be done in this
> order - if some of the packages removed by _uninstall_unneeded remove
> shared libraries, one doesn't want stale entries in ld.so.cache
> referring to those.

That's not ideal, but we could special-case ldconfig and uninstall it after this step.

> > Please consider use-cases where writable filesystems ship without ldconfig, but a user installs it from a package feed when needed.
> 
> Do you mean I should leave /etc/ld.so.conf.d/ alone? I can do that. But
> I'd say that also in that case the current behaviour is buggy - if any
> package in the rootfs ships with an /etc/ld.so.conf.d/ entry, that entry
> should be taken into account at image build time, regardless of whether
> ldconfig is there at image build time or can usefully be added later via
> a package installer.

What I meant to say is that, in general, we can't remove files from rootfs manually if they are managed by a package manager (without causing difficulties like having to reinstall glibc in this case to restore these files when needed by someone installing ldconfig from a feed). So you'd have to leave both ld.so.conf and ld.so.conf.d alone.

Best regards,
Andreas