gistfile1.builder

#!/usr/bin/env ruby

require 'open-uri'
require 'rexml/document'
require 'rexml/xpath'

url = 'http://rpm.newrelic.com/accounts.xml?include=application_health'

headers = {'x-license-key' => 'YOUR LICENSE KEY'}

app_name = 'YOUR APPLICATION NAME' # the application for which you want to collect data

name = $0.split('_').last.split('.').first.downcase

sections = {
  'cpu' => {:title => 'CPU', :metric => '%'},
  'memory' => {:title => 'Memory', :metric => 'MB'},
  'errors' => {:title => 'Errors', :metric => 'errors per minute'},
  'response' => {:title => 'Response Time', :metric => 'ms'},
  'throughput' => {:title => 'Throughput', :metric => 'calls per minute'},
  'db' => {:title => 'DB', :metric => '%'}
}

unless sections.keys.member? name
  puts "ERROR: specify section in #{sections.keys.inspect}"
  puts "example: ln -s /usr/share/munin/plugins/relic.rb relic_db"
  exit 1
end

section = sections[name]

if ARGV.first == 'autoconf'
  puts 'yes'
  exit 0
end

if ARGV.first == 'config'
  puts "graph_category New Relic"
  puts "graph_title #{section[:title]}"
  puts "graph_vlabel #{section[:metric]}"

  puts "#{name}.label #{name}"
  exit 0
end


open(url, headers) do |f|
  doc = REXML::Document.new(f.read)
  REXML::XPath.each(doc, "//application[name='#{app_name}']//threshold_value") do |metric|
    if metric.attributes['name'].downcase.match(name)
      puts "#{name}.value #{metric.attributes['metric_value']}"
    end
  end
end

Added support for having multiple applications under one account. Still works when you have only one application as long as you still specify the name of that application in the script.