Re: image-postproc-extension.bbclass modifying /etc/os-release

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

Am Mon, 18 Jan 2021 13:35:53 +0100
schrieb Claudius Heine <ch@denx.de>:

> Hi Silvano,
> 
> On 2021-01-18 12:35, Silvano Cirujano Cuesta wrote:
> > I might try to provide a fix, if we agree that the current
> > implementation has an issue.
> > 
> > @Claudius: you wrote the original code [1]. Do you remember why you
> > implemented it this way? Do you remember if you were aware of the
> > issue I mentioned and you provided a mitigation for the issue that
> > I see (assuming my analysis is right)?
> > 
> > [1]
> > https://github.com/ilbers/isar/commit/13ce96e5bc84b60f2fa7ccfe93dde045461884e6
> > 
> >    Silvano
> > 
> > On 15/01/2021 15:26, [ext] Silvano Cirujano Cuesta wrote:  
> >> Hi,
> >>
> >> I've noticed that '/etc/os-release' is being changed on the image
> >> in meta/classes/image-postproc-extension.bbclass [1].  What BTW
> >> ends up changing '/usr/lib/os-release', since it's only a symlink.
> >> But both '/etc/os-release' and '/usr/lib/os-release' are owned by
> >> 'base-files'...
> >>
> >> An upgrade of 'base-files' would be replacing (silently, since is
> >> not marked as a configuration file) '/usr/lib/os-release' with the
> >> version of the upstream 'base-files' package and possibly breaking
> >> any tools in the system relying on certain values in that file.
> >>
> >> Is there a reason that I'm missing for doing so instead of the
> >> Debian-way (file diversion with dpkg-divert)? Or any hack that
> >> I've overseen that avoids the mentioned breakage?  
> 
> Interesting, I didn't remember that `/etc/os-release` is a symlink, 
> could that be something that has changed in more recent debian
> versions?
> 
> If so then, of course that needs to be fixed.

the problem seems to be that it is a symlink, otherwise one would
assume that changes in /etc/ are allowed and covered by the config file
exception and will be subject to merging if an updated package comes
around.

My guess would be that we need to
 - make it a copy instead of a symlink
 - modify it

In this case an update of the base-files package should leave it alone
or ask for a merge. And i think that would be OK behaviour.

Henning

> regards,
> Claudius
>