[rdiff-backup-users] Running rdiff-backup restores as a different user (w/ shared group permissions on the repository)

[Charles Duffy]

I'm running backups in such a way that "rdiff-backup --server" is being 
run with uid and gid backup. I want to be able to give users who are 
allowed to run restores membership in the backup group, and arrange 
permissions such that this is sufficient to permit operation.

I've written a small patch to prevent rdiff-backup from resetting the 
umask; set said umask to allow group read and write; forcefully changed 
the file permissions in my backup directory (as a temporary measure -- 
to do it right I'm going to want to add a flag that tells rdiff-backup 
to pretend that the underlying filesystem used for storage doesn't 
support UNIX permissions) -- but even so, users other than the owner of 
the files in question are unable to do restores because rdiff-backup is 
trying to chmod the files on the server side during the restore process!


Is what I'm doing a reasonable use case? Is there a better way around 
it? Is the easiest way to fix this what I think it is (forcing the 
system to believe the server side doesn't support UNIX permissions)? If 
so, what's the easiest way to implement this -- does the straightforward 
approach involve client-side changes or only serverside ones?

Thanks!