A chef definition to allow you to build up config files for data dog. This example is for JMX...

dd_jmx_entry.rb

define :dd_jmx_entry, :jmx_port => [],:extra_config => [] do
  
  include_recipe 'recipe_which_makes_sure_data_dog_is_installed'
  
  app_name     = params[:name]
  jmx_port     = params[:jmx_port]
  extra_config = params[:extra_config]
  
  config_file_path = '/etc/dd-agent/conf.d/jmx.yaml'
  global_base_config = { 'init_config' => nil, 'instances'=> [] }

  app_config = { 'host' => 'localhost', 'port' => jmx_port, 'name' => app_name, 'conf'=> [] }
  
  memory_bean_config = {
    'include'=>
    {
      'domain'=>'java.lang', 
      'type'=>'Memory', 
      'attribute'=>
      {
        'HeapMemoryUsage.used'=>
        {
          'metric_type'=>'gauge', 
          'alias'=>'jvm.memory.heap.used'
        }
      }
    }
  }
  
  app_config['conf'] << memory_bean_config
  
  classloading_bean_config = {
    'include'=>
    {
      'domain'=>'java.lang', 
      'type'=>'ClassLoading', 
      'attribute'=>
      {
        'LoadedClassCount'=>
        {
          'metric_type'=>'gauge', 
          'alias'=>'jvm.classloading.classes.loaded'
        }
      }
    }
  }
  
  app_config['conf'] << classloading_bean_config
  
  runtime_bean_config = {
    'include'=>
    {
      'domain'=>'java.lang', 
      'type'=>'Runtime', 
      'attribute'=>
      {
        'Uptime'=>
        {
          'metric_type'=>'counter', 
          'alias'=>'jvm.runtime.uptime'
        }
      }
    }
  }
  
  app_config['conf'] << runtime_bean_config
  
  # Deal with adding extra config...
  Chef::Log.info("Adding extra JMX config for #{app_name}: #{extra_config}")
  app_config['conf'] = app_config['conf'] + extra_config
 
  config_file_template_resource = nil
  
  begin
    config_file_template_resource = resources(:template => config_file_path)
  rescue Chef::Exceptions::ResourceNotFound
    config_file_template_resource = template config_file_path do
      source 'jmx.yaml.erb' #This template simply needs to include: <%= @data.to_yaml() %>
      cookbook 'columbus_app'
      owner 'dd-agent'
      group 'root'
      mode 0644
      variables({:data => global_base_config })
      notifies :restart, 'service[datadog-agent]', :delayed
      action :nothing
    end
  end

  config_file_template_resource.variables[:data]['instances'] << app_config
  
  #Dummy resource to allow me to put delayed notification to the template
  execute 'echo noop dd_jmx_entry' do
    notifies :create, "template[#{config_file_path}]", :delayed
  end
end