Use resource_type to retrieve native ruby objects you can use with to_yaml

read_resource.rb

#!/opt/puppet/bin/ruby
require 'puppet/face'
require 'yaml'
 
Puppet.parse_config
resources = Puppet::Face[:resource_type, '0.0.1'].search('.*',{:extra => { 'environment' => 'production' }}) 
 
output = Hash.new
resources.each do |resource|
 resource.arguments.each do |k,v|
    case v.class.to_s
      when "Puppet::Parser::AST::String"
        result = v.evaluate('subscope')
      when "Puppet::Parser::AST::Undef"
        # "We don't support undef values..."
        next 
      when "Puppet::Parser::AST::Variable"
        result = "%{#{v.to_s[1..-1]}}"
      when "Puppet::Parser::AST::ASTHash"
        result = v.evaluate('subscope')
        break if result.empty?
      when "Puppet::Parser::AST::ASTArray"
        result = v.evaluate('subscope')
      when "Puppet::Parser::AST::Boolean"
        result = v.evaluate('subscope')
      else
        # "We don't support raw puppet code..."
        next
      end
    output["#{resource.name}::#{k.to_s}"] = result
  end 
end
puts output.to_yaml

$foo = generate_hiera_bindings()
file { '/etc/puppetlabs/puppet/hieradata/global.yaml':
  content => inline_template("<%= @foo.to_yaml %>"),
}