Multiple transactions on multiple packages with rpm

[Rafael Angel Garcia Leiva <angel leiva uam es>]

Dear all,

We are developing a new toolsuite for the automated installation, 
configuration and management of clusters and farms running Linux (see 
http://quattor.org for more information). The Quattor information model is 
based on the distinction between the "desired state" and the "actual state" 
of nodes. 

Regarding to software packages, we have a Software Package Management Agent  
that reads a configuration file with the target packages, compares it with  
the currently installed packages, computes the necessary  
install/deinstall/upgrade operations, and invokes the packager with the right  
operation transaction set.

The problem is that the current version of rpm can not handle multiple 
operations on multiple packages in a single transaction. Just imagine that 
you want to install 'foo' and 'bar' RPMs replacing another RPM called 
'foobar'. How can I order the operations respecting dependencies, validate, 
and execute the complete operation in one go? This is currently not possible 
in RPM (an 'rpm -e --test foobar' followed by 'rpm -i --test foo bar' does 
evidently not work).

What we have done to solve this problem is to develop a new software packager 
(called rpmt) built on top of rpmlib to handle those lists of transactions 
(if you are interested, you can download the source code from 
http://datagrid.in2p3.fr/cvsweb/edg-quattor/rpmt-4.2.1)

As we have seen, rpmlib is ready to handle such lists of transactions. It is 
possible to use rpmtsAddInstallElement() and rpmtsAddEraseElement() within 
the same transaction set. So, it seems that it would be not very difficult to 
extend rpm to handle lists of transactions. We really do not understand why 
it is not possible to do with rpm something like:

rpm -U package_1.rpm -e package_2

We would like to know if you think it is interesting to extend rpm in this 
direction, or if you have plans to do so. Even, we offer ourselves to provide 
a patch to rpm implementing the new functionality, if it is necessary.

Thanks in advance.

-- 
Rafael Angel Garcia Leiva
Universidad Autonoma Madrid
http.//www.uam.es/angel.leiva