measure-http.rb

#!/usr/bin/env ruby

Bundler.require :default

URL           = ''
METRICS_USER  = ''
METRICS_TOKEN = ''

def measure_request(url)
  t0 = Time.now
  
  http = EM::HttpRequest.new(url).get
  http.callback do
    submit_metric('web.response_time.root', t0, Time.now)
  end
  http.errback do
    submit_metric('web.response_time.root', t0, Time.now)
  end
end


def submit_metric(metric, t0, t1)
  conn = EM::HttpRequest.new("https://metrics-api.librato.com/v1/gauges/#{metric}.json")
  
  auth = "Basic %s" % Base64.encode64([ METRICS_USER, METRICS_TOKEN ].join(':')).split.join
  
  head  = { :authorization => auth }
  body = { :value => (t1 - t0).to_f, :measure_time => t0.to_i }

  http = conn.post :body => body, :head => head
  http.callback do
    puts "success: #{(t1 - t0).to_f}"
  end
  
  http.errback do
    puts "error: #{http.response.inspect}"
  end
end


EM.run do
  EventMachine.add_periodic_timer(1) do
    measure_request(URL)
  end
end