Exported resource query/collection in ruby puppet dsl

1. Export stuff.

FACTER_fqdn=host1 puppet --certname host1 --node_name fqdn --storeconfigs --dblocation /tmp/puppet.sqlite -e '@@nagios_hostgroup { "mygroup": notes => "Hello"; }'
FACTER_fqdn=host2 puppet --certname host2 --node_name fqdn --storeconfigs --dblocation /tmp/puppet.sqlite -e '@@nagios_hostgroup { "mygroup": notes => "Hello"; }' 

2. testpuppet.rb (ruby puppet dsl)

# Define a class that provides a bunch of Nagios_hostgroup resources.
# These resources are defined by already-exported Nagios_hostgroups.
# This will also go through and prune out duplicate exports.
require "puppet/rails/resource"

hostclass :happy do
  found = Set.new
  Puppet::Rails::Resource.find_all_by_restype("Nagios_hostgroup").each do |resource|
    # Skip duplicate resource titles
    key = [resource.restype, resource.title]
    next if found.include?(key)
    found << key
    
    # Build a hash of parameters for this resource
    params = {}
    resource.param_values.each do |pv|
      name = pv.param_name.name
      params[name] = pv.value
    end 
    
    # Override the target file for this example
    params[:target] = "/tmp/example_nagios_config"

    # Now create the resource.
    nagios_hostgroup resource.title, params
  end
end

node :default do
  include "happy"
end

3. Run it.

 % puppet apply --verbose --storeconfig --dblocation /tmp/puppet.sqlite testpuppet.rb
info: Connecting to sqlite3 database: /tmp/puppet.sqlite
info: Caching catalog for snack.home
info: Applying configuration version '1291931649'
notice: /Stage[main]/Happy/Nagios_hostgroup[mygroup]/ensure: created

4. Show it

snack(~) % cat /tmp/example_nagios_config 
# HEADER: This file was autogenerated at Thu Dec 09 13:54:10 -0800 2010
# HEADER: by puppet.  While it can still be managed manually, it
# HEADER: is definitely not recommended.
define hostgroup {
        notes                          Hello
        hostgroup_name                 mygroup
}

Try this:
# Build a hash of parameters for this resource
params = Hash[ resource.param_values.map{ |pv| [ pv.param_name.name, pv.value ] } ]