Munin contributed plugins

#!/usr/bin/env ruby

#

#	unicorn_status - A munin plugin for Linux to monitor unicorn processes

#

#  Copyright (C) 2010 Shinji Furuya - shinji.furuya@gmail.com

#  Licensed under the MIT license:

#  http://www.opensource.org/licenses/mit-license.php

#

# set path to your rails app

RAILS_ROOT = "/path/to/rails/app"

module Munin

  class UnicornStatus

    attr_reader :pid_file

    def initialize(rails_root)

      @pid_file = "#{rails_root}/tmp/pids/unicorn.pid"

    end

    def master_pid

      File.read(pid_file).to_i

    end

    def worker_pids

      result = []

      ps_output = `ps w --ppid #{master_pid}`

      ps_output.split("\n").each do |line|

        chunks = line.strip.split(/\s+/, 5)

        pid, pcmd = chunks[0], chunks[4]

        next if pid !~ /\A\d+\z/ or pcmd !~ /worker/

          result << pid.to_i

      end

      result

    end

    def worker_count

      worker_pids.size

    end

    def idle_worker_count

      result = 0

      before_cpu = {}

      worker_pids.each do |pid|

        before_cpu[pid] = cpu_time(pid)

      end

      sleep 1

      after_cpu = {}

      worker_pids.each do |pid|

        after_cpu[pid] = cpu_time(pid)

      end

      worker_pids.each do |pid|

        result += 1 if after_cpu[pid] - before_cpu[pid] == 0

      end

      result

    end

    def cpu_time(pid)

      usr, sys = `cat /proc/#{pid}/stat | awk '{print $14,$15 }'`.strip.split(/\s+/).collect { |i| i.to_i }

      usr + sys

    end

  end

end

case ARGV[0]

when "autoconf"

  puts "yes"

when "config"

  puts "graph_title Unicorn - Status"

  puts "graph_args -l 0"

  puts "graph_vlabel number of workers"

  puts "graph_category Unicorn"

  puts "total_worker.label total_workers"

  puts "idle_worker.label idle_workers"

else

  m = Munin::UnicornStatus.new(RAILS_ROOT)

  puts "total_worker.value #{m.worker_count}"

  puts "idle_worker.value #{m.idle_worker_count}"

end