Catalog terminus to inject node data

compiler_factmerge.rb

# Example catalog terminus

require 'puppet/indirector/catalog/compiler'

class Puppet::Resource::Catalog::CompilerFactmerge < Puppet::Resource::Catalog::Compiler

  def find(request)
    if request.options[:use_node]
      request.options[:use_node].add_extra_facts(node_data)
    else
      facts = extract_facts_from_request(request)
      facts.add_extra_values(node_data)
      request.options[:facts] = Puppet::Util.uri_query_encode(facts.render('json'))
      request.options[:facts_format] = 'application/json'
    end

    super(request)
  end

  def node_data
    data = {}

    # This is where the API call should be made to retrieve the data
    data['test'] = 'example'

    {'node_data' => data}
  end

end

node_data.rb

# Example custom fact

Facter.add(:node_data) do
  setcode do
    data = {}

    # This is where the API call should be made to retrieve the data
    # Should use Puppet agent's certificate for auth/identity
    data['test'] = 'example'

    data
  end
end

puppet.conf

# Config required in the master's puppet.conf to use catalog terminus

[master]
catalog_terminus = compiler_factmerge