Re: [gentoo-dev] Managing etc/* in an embbeded system

[Joakim Tjernlund]

On Wed, 2015-07-22 at 22:38 +0800, Jason Zaman wrote:

> On Wed, Jul 22, 2015 at 01:20:10PM +0000, Joakim Tjernlund wrote:
> > On Wed, 2015-07-22 at 14:30 +0200, Michał Górny wrote:
> > >
> > > Joakim Tjernlund <joakim.tjernlund@×××××××××.se> napisał:
> > >
> > > > We got an embedded gentoo system where we need to manage many conf
> > > > files under /etc that we have
> > > > modified and should be under our control when an SW upgrade is
> > > > performed.
> > > >
> > > > Cloning every ebuild where we have modified its conf file(s) under /etc
> > > > feels awkward so
> > > > I am looking for some other way to do this automatically during SW
> > > > upgrade and I figured
> > > > this can not be an unique problem for us, so I wonder how other people
> > > > have solved this problem?
> > > > Our customers will not use emerge directly and we will provide binary
> > > > pkgs.
> > > >
> > > > Any ideas welcome :)
> > > >
> > > > Jocke
> > >
> > > Maybe post-phase hooks would help you. Not around a PC right now but I think they're described in
> > > portage.5.
> > > Long story short, you create per-package env files in /etc/portage/env (you can pin them generically or
> > > to a
> > > specific version, or package spec via package.env) and declare post_src_install() where you add your
> > > custom
> > > config files atop the package.
> > >
> >
> > hmm, that sounds interesting but I don't quite get what to do, you think I should copy over /etc/inittab
> > after
> > it has been installed by sys-apps/sysvinit with my own version(which is stored where?)
> >
> > This gave me an idea though:
> > In /etc/portage/env/install-mask.conf I add
> >   INSTALL_MASK="${INSTALL_MASK} /etc/inittab /etc/xxx"
> > then in /etc/portage/package.env/install-mask
> >   sys-apps/sysvinit install-mask.conf
> >   sys-apps/xxx install-mask.conf
> >   ...
> > (Can I do this from my own custom profile instead? how?)
> >
> > This should prevent sys-apps/sysvinit to install conf files I want to manage, right?
> >
> > Then I create my own new ebuild holding all config files I have changed myself.
>
> Or you can put a script in /etc/portage/hooks/install/, it will get run
> after src_install() during generation of VDB and all that, you could
> probably move everything from /etc/ to /etc-orig/ then all packages will
> be have things set there, then put your own files in /etc and you can
> always refer to /etc-orig/ or even use overlayfs or something to mount
> your files on top so they cover the package ones.


This also seems viable, need to look at hooks and such though. Are such hooks native to portage?



 Jocke