Hiera support for Aggregate Fact Resolution?

[Garrett McGrath]

Is there a known way to do this or anything on the horizon that would make this functionality easier?

I am attempting to use facts.d to establish a list of 'roles' that resolve to locations in my hiera hierarchy (- roles/%{::roles}). Unfortunately it doesn't actually work as expected right now because hiera is restricted to interpolating values as strings instead of arrays or hashes, features added to facter in 2.0.  It will work one time but then puts the puppetmaster / passenger server in a weird state that requires touching a file in the manifest structure or restarting the server in order to continue working.  Further it only appears to access the first role when doing this which is an additional problem.

Having fully formed and functional support for this would allow me to eliminate huge amounts of repeated data in my current hiera structure so hopefully there is a way to get this doing what I want.

-Garrett