Modifying other packages' conffiles: the not-so-ideal way

[frank@kuesterei.ch (Frank Küster)]

Hi,

policy says in section 10.7.4:

,----
| If it is desirable for two or more related packages to share a
| configuration file and for all of the related packages to be able to
| modify that configuration file, then the following should be done:
| 
|    1. One of the related packages (the "owning" package) will manage
|    the configuration file with maintainer scripts as described in the
|    previous section.
|
|    2. The owning package should also provide a program that the other
|    packages may use to modify the configuration file.
|
|    3. The related packages must use the provided program to make any
|    desired modifications to the configuration file.
`----

So this is clearly the ideal way. However, it says "it should", so it's
not a must under all circumstances. Now if there isn't yet such a
program, or will not be in the near future because the maintainer of the
owning package doesn't regard the case important enough, how should one
act then?

One option, of course, would be to not modify the file at all, but refer
the user to the documentation of the package that needs the file to be
modified. The problem with this is that most users will simply cut&paste
the suggested lines into the conffile without respecting the advice
given before, namely, to read and understand it.

So the alternative is to provide a configuration script to do that. This
script can check one way or the other wether the conffile looks like it
expects it to do, if there are conflicting options etc. From this point
of view, I would consider this solution better than just documenting
what should be done.

If the package in question won't work at all under certain circumstances
(tested in the config file), the next, logical step would be to run the
configuration script in postinst. But this violates a must-clause of
Policy:

,----
| The maintainer scripts must not alter a conffile of any package
`----

So obviously my thoughts went in the wrong direction...

In reality, I have contacted the maintainer of the "owning" package and
hope that we'll find a clean solution. Still, since the question came to
my mind, I would like to hear your comments.

Thanks, Frank
-- 
Frank Küster, Biozentrum der Univ. Basel
Abt. Biophysikalische Chemie