service iptables save, systemctl, and unhelpful error messages

[Emanuel Rietveld]

Currently, on Fedora 16, service iptables save prints the following:

# service iptables save
Redirecting to /bin/systemctl  save iptables.service
Unknown operation save

The service iptables save command is documented in a number of places 
and has been recommended to users for years. See, for example, the 
security guide: 
http://docs.fedoraproject.org/en-US/Fedora/16/html/Security_Guide/sect-Security_Guide-Using_IPTables-Saving_and_Restoring_IPTables_Rules.html

This breaking with the systemctl move is expected, but the unhelpful 
error message is a usability bug. Executing services iptables save 
should print "This is no longer supported. Please execute 
/usr/libexec/iptables.init save" (See: 
https://bugzilla.redhat.com/show_bug.cgi?id=748134 )

 From a technical perspective, that would mean the /sbin/service wrapper 
would need to be rewritten check a file for the command that is being 
asked to do, and print different error messages depending on the situation.

Of course that makes the currently simple wrapper script more complex, 
but if we want to keep moving forward as fast as Fedora is, we should 
make the extra effort to stay friendly to our users too.

Emanuel