Re: [PATCH 0/4] add support for OE's ROOTFS_*_COMMAND

[Henning Schild <henning.schild@siemens.com>]

Am Tue, 30 Oct 2018 11:02:49 +0000
schrieb "Hombourger, Cedric" <Cedric_Hombourger@mentor.com>:

> prelink or ima would not be considered hacks or kludges but
> definitely things you apply on the complete file-system. I am failing
> to understand your resistance... Yocto is no different, have you
> looked at their uses of the pre/post rootfs commands? They also have
> packages and apply package level optimizations in their recipes (and
> we also should) but the aforementioned examples do not fit this
> category at all 

The resistance comes from a mechanism without a user, a mechanism that
can (and will) be abused. First hit on google ...
https://stackoverflow.com/questions/36863682/yoctos-rootfs-postprocess-command-not-working
Once we have the use-case we can find the right mechanism or add a new
one.

Have a look at IMAGE_TRANSIENT_PACKAGES. I think prelink could be done
with an apt hook as well, so you have a raw pkg depending on prelink and
shipping the apt config.

Henning

> Looking forward to your response
> 
> Sent from a mobile
> 
> > On 30 Oct 2018, at 10:26, Henning Schild
> > <henning.schild@siemens.com> wrote:
> > 
> > Am Mon, 29 Oct 2018 16:55:10 +0000
> > schrieb "Hombourger, Cedric" <Cedric_Hombourger@mentor.com>:
> >   
> >> Sure thing. This will allow us to generate license/package
> >> manifests like Yocto does amongst other things (eg rootfs
> >> optimization functions). In other words system wide tweaks. The
> >> former is the subject of an upcoming patch series.  
> > 
> > rootfs optimization functions sounds very much like hacking your way
> > around the golden rule i mentioned earlier. And since people will
> > abuse such a mechanism it is best to not introduce it.
> > 
> > For the license manifests ... that sounds interesting indeed but
> > will likely not require such a generic mechanism.
> > 
> > I guess concrete examples would be useful. But looking just at the
> > mechanism without such examples, i am strongly against merging that
> > code.
> > 
> > Henning
> >   
> >> Sent from a mobile
> >>   
> >>> On 29 Oct 2018, at 17:45, Henning Schild
> >>> <henning.schild@siemens.com> wrote:
> >>> 
> >>> Hey,
> >>> 
> >>> could you please elaborate on why this is needed and what you want
> >>> to do with it? I suspect there are already other ways of doing
> >>> what you might want to do.
> >>> 
> >>> One golden rule is that _everything_ inside the rootfs comes from
> >>> a .deb package. If you need to execute scripts, go for post/pre
> >>> inst etc.
> >>> 
> >>> Henning
> >>> 
> >>> Am Mon, 29 Oct 2018 17:12:59 +0100
> >>> schrieb Cedric Hombourger <Cedric_Hombourger@mentor.com>:
> >>>   
> >>>> OpenEmbedded allows custom functions to be called at various
> >>>> stages of the root file-system generation process. Add similar
> >>>> capabilities to Isar.
> >>>> 
> >>>> Cedric Hombourger (4):
> >>>> isar-image-base: introduce and use isar-image class
> >>>> isar-image: refactor do_rootfs()
> >>>> base: add 'lib' folder of each layer to python's module search
> >>>> path isar-image: add support for OE's ROOTFS_*_COMMAND
> >>>> 
> >>>> doc/user_manual.md                                 | 43
> >>>> +++++++++++ meta-isar/classes/isar-image.bbclass               |
> >>>> 89 ++++++++++++++++++++++ .../files =>
> >>>> conf/distro}/debian-configscript.sh   |  0 .../files =>
> >>>> conf/distro}/raspbian-configscript.sh |  0
> >>>> meta-isar/recipes-core/images/isar-image-base.bb   | 57
> >>>> +-------------
> >>>> meta/classes/base.bbclass                          | 4 +
> >>>> meta/lib/oe/utils.py                               | 11 +++ 7
> >>>> files changed, 150 insertions(+), 54 deletions(-) create mode
> >>>> 100644 meta-isar/classes/isar-image.bbclass rename
> >>>> meta-isar/{recipes-core/images/files =>
> >>>> conf/distro}/debian-configscript.sh (100%) rename
> >>>> meta-isar/{recipes-core/images/files =>
> >>>> conf/distro}/raspbian-configscript.sh (100%) create mode 100644
> >>>> meta/lib/oe/utils.py 
> >>>   
> >