fcarbon

etc_init_fcarbon.conf

description "fcarbon"
author "Joe Topjian"

start on (local-filesystems and net-device-up IFACE=eth0)
stop on runlevel [016]

respawn
respawn limit 5 60

exec /usr/local/bin/fcarbon.rb

fcarbon.rb

#!/usr/bin/env ruby
require 'logger'
require 'bunny'
require 'yaml'
require 'graphite-api'
require 'pp'

config = YAML.load_file('/etc/carbon/fcarbon.yaml')
g = GraphiteAPI.new( graphite: config['graphite_host'])
l = Logger.new('/var/log/fcarbon.log')
l.level = Logger.const_get config['log_level']

connections = {}

while true do
  config['amqp_servers'].each do |location, info|

    connection = nil
    channel = nil
    exchange = nil
    queue = nil

    begin
      connection = Bunny.new(info['rabbit_host'])
      connection.start
      channel = connection.create_channel
      exchange = channel.topic(info['topic'], :durable => false, :auto_delete => false)
      queue = info['queue']
      l.info("Connected to #{location}.")
    rescue
      l.info("Can't connect to #{location}. Will try again next time.")
      next
    end

    begin
      l.info("Entering event loop for #{location}.")

      channel.queue(queue, :exclusive => false).bind(exchange).subscribe do |d, prop, pay|
        metrics = pay.split("\n")
        metrics.each do |metric|

          l.debug("Processing metric #{metric}")

          m = metric.split(/\s+/)
          next if m.length < 3

          time = m.pop.strip.to_i
          value = m.pop.strip
          rest = m.pop

          # Because hostnames come in as server.domain.tld, Graphite will make a subdir for each .
          # We want to change the hostname to server_domain_tld while still retaining other subdomains
          # To do that, config['hostname_regex'] contains a regex to match
          r = Regexp.new(config['hostname_regex'])
          m = r.match(rest)
          if m
            host_metric = rest.sub(m[1], m[1].gsub('.', '_'))
          else
            host_metric = rest
          end

          g.metrics(
            { host_metric => value }, Time.at(time)
          )
        end
        l.info("Exiting event loop for #{location}.")
        connection.close
      end
    rescue
      next
    end
  end
  sleep 60
end

fcarbon.yaml

---
  log_level: DEBUG
  graphite_host: "localhost:2003"
  amqp_servers:
    yyc:
      topic: metrics
      queue: metrics
      rabbit_host: "amqps://sensu:[email protected]:5672/sensu"
    yeg:
      topic: metrics
      queue: metrics
      rabbit_host: "amqps://sensu:[email protected]:5672/sensu"
    hnl:
      topic: metrics
      queue: metrics
      rabbit_host: "amqps://sensu:[email protected]:5672/sensu"
  hostname_regex: "^(.+?\x5c.ca|.+?\x5c.com)\x5c..*$"