Re: Review request: debconf templates for mrtg

On Wed, 16 Aug 2023 17:11:17 +0100
Justin B Rye <[email protected]> wrote:

> Eriberto Mota wrote:
> > You are right again. However, this is a big effort for a minimum of
> > machines (or none for now) in this situation. I decided just to show
> > a message for the users.
> 
> Are you saying most MRTG users don't have any customisations in their
> mrtg.cfg that they'll need to keep, or just that MRTG has a very low
> popcon, or what?


This is a very specific package (for networks), and I think several
managers already migrated their conf files. The configuration options
are the same along several years. The users only need to move the
/etc/mrtg.cfg to /etc/mrtg/.

  
> >> Just for the exercise, I'll review the text anyway.
> >> 
> >>   Template: mrtg/move_config_file
> >>   Type: note
> >>         ^^^^
> >> If the new mrtg will ignore /etc/mrtg.cfg, this should probably be
> >> "Type: warning".
> > 
> > I understand your suggestion, but "warning" is not acceptable for "Type"
> > in debconf[1].
> > 
> > [1] https://www.debian.org/doc/packaging-manuals/debconf_specification.html#id-1.4.4.3.1
> 
> Apparently I'm badly out of practice for these template reviews - I've
> got that page bookmarked, but I was misremembering it as "note" versus
> "warning" instead of "text" versus "note".


note is better than text for this case.


> >>   _Description: /etc/mrtg.cfg should be moved to /etc/mrtg/mrtg.cfg
> >>   Older versions of MRTG on Debian had the configuration file /etc/mrtg.cfg.
> >>   This file should now be located in the directory /etc/mrtg/. The Debian
> >>                                                                ^^^
> >> Just "Debian Policy", no "The".
> >> 
> >>   Policy doesn't allow the installation system to change the place of the
> >> 
> >> This isn't true.  Meanwhile, we try to avoid letting debconf talk
> >> about debconf, and it can be confusing to mention installation in a
> >> prompt that might be shown during a routine upgrade.
> >> 
> >>   configuration files already present in the system (see Policy 10.7.3).
> >>   Please, consider to make the needed adjustments in your system manually.
> > 
> > I will use "installer". I think is important to say this word.
> 
> I can't see why.  The (Debian-)Installer is a completely different
> thing; and users will only see this message during a (multi-)package
> (dist-)upgrade, not when they're running a fresh "apt install mrtg".
> 
> If you need to talk about the internals at all, you might say "Policy
> doesn't allow a package upgrade process to do X", but I don't think
> you need to mention Debian Policy here at all - it just gives the
> unfortunate impression that you're complaining about having to produce
> a package that isn't buggy!
> 
> >> This seems an unnecessarily gentle suggestion, and it doesn't need to
> >> mention "in your system" - just say
> >> 
> >>   Please make the required adjustments manually.
> > 
> > My new approach is now:
> > 
> > Template: mrtg/move_config_file
> > Type: note
> > _Description: /etc/mrtg.cfg should be moved to /etc/mrtg/mrtg.cfg
> >  Older versions of MRTG on Debian had the configuration file /etc/mrtg.cfg.
> >  This file should now be located in the directory /etc/mrtg/.
> >  .
> >  Debian Policy doesn't allow the installer to move a file from a place to
> >  another, discarding any user changes (see Policy 10.7.3). Please, make the
> >  required adjustments manually.
> 
> This implies that moving files results in discarding user changes.
> No, it's using direct "mv" commands in the postinst that results in
> bugs.  Maybe the diplomatic way of saying "I can't be bothered to do
> the whole officially approved mv_conffile song and dance routine for
> this" is something like
> 
>   Older versions of MRTG on Debian had the configuration file /etc/mrtg.cfg.
>   The new version reads from /etc/mrtg/mrtg.cfg instead.
>   .
>   Migrating local customizations to the new location is too complicated to
>   automate at present, so you will need to move your configuration across
>   manually.
> 
> Or maybe "so MRTG will not work correctly until you move your
> configuration across manually"?


I don't like to say "is too complicated to automate at present". I will opt to
say only:

   Older versions of MRTG on Debian had the configuration file /etc/mrtg.cfg.
   The new version reads from /etc/mrtg/mrtg.cfg instead.
   .
   MRTG will not work correctly until you move your configuration across
   manually.


> > What you think?
> 
> I'm assuming that the obvious user-visible effect of this change is
> that the new version of MRTG will ignore the customisations that are
> in the old location.  

Yes.

> I'm also assuming that it's only showing this
> template to users with a customised /etc/mrtg.cfg, not unconditionally
> on upgrade -

If the user has a /etc/mrtg.cfg, the message will be shown. It will avoid
a mistake from a user trying to configure /etc/mrtg.cfg instead of
/etc/mrtg/mrtg.cfg some days after an upgrade.

> oh, except now I see that the default mrtg.cfg is almost
> empty, and there's a special "cfgmaker" script for generating a
> version that will work for your network setup.  So are users more
> likely to want to do this migration with "mv" or "cfgmaker"?


mv, sure. In my personal case, I never used cfgmaker. I write all lines.
The syntax is easy and well documented.


> (If the latter, we might perhaps warn them that "sudo COMMAND > FILE"
> can only modify a FILE that your current user has write-access to...)

Thanks again.

Eriberto