Re: MTA packaging (exim, postfix, sendmail, ssmtp)

[Christian Franke <Christian dot Franke at t-online dot de>]

Yaakov Selkowitz wrote:
> On 2014-10-08 07:52, Corinna Vinschen wrote:
> > On Oct  6 17:19, Yaakov Selkowitz wrote:
> > > Because MTAs must be user-configured, and we certainly don't want to 
> > > lose
> > > the selection during package upgrades, the alternatives cannot be 
> > > handled in
> > > package postinst/prerm.  I think the only way to make this work is 
> > > for each
> > > MTA config script to handle these instead by including the following
> > > snippets in the respective MTA config scripts.
> > >
> > > Please review this carefully in case I missed anything.
> >
> > The ssmtp part looks ok to me.  Two questions:
> >
> > - Don't we have to add something to preremove as well?
>
> No, because we don't distinguish between removing and upgrading a 
> package in preremove.  Whenever a user wishes to switch MTAs, they 
> will need to run alternatives --set, preferably via the MTA config 
> scripts.

The cron package is also affected. Its postinstall script sets a symlink 
/usr/sbin/sendmail -> /usr/bin/cronlog if sendmail does not exist. This 
would break alternatives setting in MTA configure script because 
alternatives would never replace the existing symlink.

Possible workaround: Add rm -f /usr/sbin/sendmail ... to MTA configure 
scripts.

Christian