Re: freeswan transition package

[Frank Küster <frank@debian.org>]

Rene Mayrhofer <rene.mayrhofer@gibraltar.at> schrieb:

> I am seeking advice for creating a transition package for freeswan, which 
> should:
> - install the openswan package
> - use the config files from the old freeswan package for openswan
> - use the debconf answers of the old freeswan package for openswan
>
> I have tried to RTFM, but not found a "HOWTO make a good transition package" 
> somewhere, especially w.r.t. handling the config file problem. The config 
> files are - before the installation of the transition package - associated to 
> the freeswan package and should - after the installation of the freeswan 
> transition package - be assigned to openswan. What is the best way to achieve 
> this?

The debconf answer part should be easy, just read the old answers and
db_purge them after you've done that successfully. 

For the transition of conffiles, I think the way to go is to use
ucf. ucf will give a configuration file dpkg-like conffile protection
although they are not conffiles.

- The new configuration files are shipped in /usr/share/openswan/
  instead of their intended location in /etc; the old versions are
  registered in the md5sum files in the same directory

- In preinst, you move/rename the existing conffiles 

- In postinst, you let ucf do the work (recognize the existing versions
  as known if they are unchanged and copy the new ones to their places,
  or show the user a diff if he has changed the conffiles).


Regards, Frank
-- 
Frank Küster
Inst. f. Biochemie der Univ. Zürich
Debian Developer