yum-deltarpm (Was Thread Hijack - Our package management GUI tools need improvement)

[Warren Togami]

Ahmed Kamal wrote:
> 
>     The reconstruction doesn't require the local files marked %config to be
>     the original file right?  Any other local files it explicitly doesn't
>     rely upon?
> 
> 
> 
> Um, not sure. But it does have to reconstruct the new rpm, and that rpm 
> would have to pass md5/sha1/gpg checks! Doesn't that mean even %config 
> files have to be untouched?! I need to double check how this is handled

1) Client wants to upgrade from foo-3.2-1 to foo-3.2-2 (Transition X)
2) Client metadata sees that Transition X has a drpm available (from 
metadata or something).
3) Client checks using rpm -V (or more likely the rpm API equivalent) to 
see if the local files are intact.  This step is a little time 
consuming, but it is worthwhile because we know that a drpm is available 
above the defined efficiency threshold.
4) All files are intact, except some files in /etc marked %config are 
changed.  This is OK.
5) drpm contains %config file data even if they did not change in 
Transition X.  This allows reconstruction of the original foo-3.2-2 RPM 
even if the local %config files are modified.

deltarpm needs to put data within the drpm that is likely to change on 
the local systems.  This includes %config, but possibly other things 
like /var.  We can craft this predefined list to whatever our research 
finds is necessary.

Warren Togami
wtogami at redhat.com