We support parsing of custom facts for IPMI devices and link status in discovery, we should add an easy way to propagate them to normal puppet agents. Also similar is needed for fixing vlan vs aliases fact conflicts until they fix it in upstream (https://tickets.puppetlabs.com/browse/FACT-701)

We could either add things to https://github.com/theforeman/puppet-foreman/blob/master/lib/puppet/parser/functions/foreman.rb or create a separate module (foreman_functions?) which would contain all of this stuff, but contains no classes (thus preventing namespace conflict or dependency clashes).
As discussed though, it must be optional.