getfacts.rb

#!/usr/bin/env ruby

require 'jgrep'

def get_facts(facter_version, filter)
  filter_str = filter.map { |f| f.map { |k,v | "#{k}=#{v}" }.join(' and ') }.join(' or ')

  jsons = Dir.glob("facts/#{facter_version}/*.facts").map { |f| File.read(f) }
  json = "[#{jsons.join(',')}]\n"
  JGrep.jgrep(json, filter_str)
end

require 'yaml'

facter_version = '2.4'
filter = [
  {
    :operatingsystem => 'Debian',
    :operatingsystemmajrelease => '8'
  },
  {
    :operatingsystem => 'RedHat',
    :operatingsystemmajrelease => '7'
  },
  {
    :operatingsystem => 'Archlinux'
  }
]
puts get_facts(facter_version, filter).to_yaml