(#22604) Ohai facts terminus

[dalen]

Ohai supports a lot of stuff Facter doesn't. This patch adds support for
fetching facts from ohai instead.

[puppetcla]

CLA signed by all contributors.

[adrienthebo]

I think this probably belongs in group extra.

[dalen]

Sure, I can move that. Wasn't entirely sure what all the different groups were for.

[adrienthebo]

In theory, couldn't this and GH-1912 done much more easily with a custom fact?

require 'ohai'

o = Ohai::System.new
o.all_plugins
o.data.each_pair do |k, v|
  Facter.add(k) { setcode { v } }
end

[ahpook]

I'd like to see this in a module rather than merged into core, and I'd also like to understand what facter should do that it doesn't currently (aside from nested data structures, about which I'm painfully aware).

[dalen]

Nested data structures & facts amending each other mainly. Then even if facter does nested data structures all the existing facts still have to be converted to a decent structure (which ohai already has in place).

Inventing our own structure for it seems a little bit like reinventing the wheel tbh and both communities would probably benefit in the long run by sharing this component.

[grimradical]

While I 1000% sympathize with the motivations here, I agree with @ahpook that this is better introduced in a module at first.

If there are limitations that prevent this from working as a module, though, we should definitely fix those!