Reads metrics that Finagle exposes on a port and converts them into Graphite format.

sensu_finagle_metrics.rb

#!/usr/bin/env ruby
#
# This script gets Finagle metrics from various applications
# Written By: https://github.com/elocnatsirt

# Options:
# -h = host that you want to query - defaults to localhost
# -p = port of the nimbus node you want to query - defaults to 9990

require 'socket'
require 'English'
require 'sensu-plugin/metric/cli'

class FinagleMetrics < Sensu::Plugin::Metric::CLI::Graphite
  option :host,
         short: '-h URL',
         long: '--host URL',
         description: 'valid url to connect',
         default: 'localhost'

  option :port,
         short: '-p PORT',
         long: '--port PORT',
         description: 'port to connect',
         default: '9990'

  option :scheme,
         description: 'Metric naming scheme, text to prepend to metric',
         short: '-s SCHEME',
         long: '--scheme SCHEME',
         required: true,
         default: "#{Socket.gethostname}.finagle_metrics"

  def run
    cmd = "curl --silent #{config[:host]}:#{config[:port]}/admin/metrics.json?pretty=true | sed 's/[{}]//g;/^\s*$/d;s/,//;s/\"//g;s/ //g'"
    metrics = `#{cmd}`
    time = Time.now.to_i

    metrics.each_line do |metric|
        (metric_name, metric_total) = metric.split(':')
        puts "#{config[:scheme]}.#{metric_name} #{metric_total.chomp} #{time}"
    end

    if $CHILD_STATUS.to_i == 0
      ok
    else
      warning
    end
  end
end

I wrote this to get finagle metrics from our various applications that expose them. The metrics are read from a page that displays them in a JSON structure and just has basic key/value pairs and transforms them into the graphite format. In theory you could use this for any anything that outputs data in that basic format; however it will not handle any nested structures inside the main one.