[oe] /usr merge, stateless systems and atomic updates w/ OpenEmbedded?

[Jussi Kukkonen]

On 15 January 2017 at 01:41, Leon Woestenberg <leon at sidebranch.com> wrote:

> Hello Khem,
>
> I know outside of OE it is more and more common place, such as Project
> Atomic.
>
> Re-reading some of the material I have found, I found that Chen Qi of Wind
> River had something going.
>
> http://lists.openembedded.org/pipermail/openembedded-core/
> 2014-December/099616.html
>
> >* > Several days ago, I tried to do /usr merge in OE (like what Fedora and
> *>* > Arch does). It turned out that we need to patch several packages to
> make
> *>* > things work.
> *>* >
> *>* > (I haven't sent out the patches because it's just some initial
> *>* > investigation and I'm not sure if people want this feature or not.)
> *>* >
> *>* > If you want this feature in OE, please open a bug/enhancement in
> *>* > bugzilla https://bugzilla.yoctoproject.org/
> <https://bugzilla.yoctoproject.org/> to see if the community
> *>* > wants it or not.
> *>* >
> *>* > Regards,
> *>* > Chen Qi*
>
> and in Yocto an enhancement is going for usrmerge:
> https://bugzilla.yoctoproject.org/show_bug.cgi?id=7040


Hi Leon,

Me and Amarnath Valluri have been testing "merged /usr" this month: I
expect there will be a oe-core patchset for review later this week -- I'll
CC you when that happens.

The possible approaches seem to be:
 1) Modify $base_bindir (et al) so that all recipes actually install under
/usr/, fix recipes that misbehave
 2) Don't modify $base_bindir (et al), just make sure the symlinks (like
/bin -> /usr/bin) are there when packages are installed on the rootfs

Both approaches have some package management related issues but can be made
to work (we're leaning towards #1 at the moment).

I'm not promising anything about Stateless yet.

Jussi