rpm-ostree/design/package-layering.md

rpm-ostree should support layering packages on top of a base tree. Use cases:

• As a system administrator, I need to use a profiling/debugging/tracing tool like perf, strace, nmap

• As a system administrator, I prefer Emacs over vi/nano

The design here is this:

$ rpm-ostree add emacs

This will

• Resolve dependencies between the requested emacs package and what we have installed
• Download all packages
• Check out via hardlinks a new copy of the base tree
• Unpack and install all requested layered RPMs on top. This requires that the %post scripts are whitelisted http://lists.rpm.org/pipermail/rpm-maint/2014-April/003682.html
• Commit that tree as a local branch
• Deploy that branch for the next boot

In this model, you will then have to reboot to install Emacs. A future step for rpm-ostree will be applying partial live updates: http://blog.verbum.org/2014/02/26/ostree-rigorous-and-reliable-deployment/