Custom rsyslog output program to send metrics to Graphite via Carbon

metric_handler.rb

#!/bin/env ruby

require 'time'
require 'socket'

class GraphiteClient
  def carbon
    begin
      @carbon ||= TCPSocket.new('localhost', 2003)
    rescue => e
      @carbon = nil
    end

    @carbon
  end

  def send(data)
    begin
      carbon.puts(data) if carbon
    rescue => e
      @carbon = nil
    end
  end
end

class MetricHandler
  def initialize
    @client = GraphiteClient.new
  end

  def run
    while line = gets
      begin
        # 2014-02-27T14:50:22.011665-05:00
        fields = line.split(' ')
        timestamp = Time.parse(fields[0]).to_i
        app = $1 if line =~ /app=([^ ]+)/
        gear = $1 if line =~ /gear=([^ ]+)/

        # skip if we don't have app and gear
        next unless app and gear
        
        fields.each do |field|
          if field =~ /([^=]+)=(.+)/
            key = $1
            next if %w(app gear type).include?(key)

            value = $2

            @client.send "#{app}.#{gear}.#{key} #{value} #{timestamp}"
          end
        end
      rescue => e
        raise
      end
    end
  end
end

MetricHandler.new.run