cleanest way of excluding sub-array in chef node attributes

config.rb

default['mongodb']['sysconfig']['ulimit']['file_limit'] = 12345
default['mongodb']['sysconfig']['ENABLE_MONGODB'] = "yes"
default['mongodb']['sysconfig']['port'] = 27107

mongo.default.erb

#
# Automatically generated by chef, do not edit directly!
#

<% node['mongodb']['sysconfig'].to_hash.keys.sort.each do |key| %>
<% if node['mongodb']['sysconfig'][key].kind_of? String or node['mongodb']['sysconfig'][key].kind_of? Integer %>
<%= key %> = <%= node['mongodb']['sysconfig'][key] %>
<% end %>
<% end %>