mongrel_process_memory

#!/usr/bin/env ruby

=begin

mongrel_process_memory - A munin plugin to monitor memory size of
                         each individual mongrel process
Copyright (C) 2007 Ben VandenBos and Avvo, Inc.

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License version 2
as published by the Free Software Foundation.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

Author: Ben VandenBos
Contributors: Adam Jacob (<adam@hjksolutions.com>)
              Ryan Woodrum

#%# family=auto
#%# capabilities=autoconf

=end

module Munin
  class MongrelProcessMemory
    def run
      h = get_pids
      ps_output = ''
      # I have no doubt that this is a terrible way of doing this.
      h.each do |k, _v|
        ps_output += `ps --no-heading l #{k}`
      end

      if ps_output
        port_list = {}
        ps_output.each_line do |l|
          next unless l =~ /-p (\d+)/

          port = Regexp.last_match(1)
          l_ary = l.split(/\s+/)
          port_list[port] = l_ary[7].to_i * 1024 if l_ary.length > 6
        end
        port_list.sort.each do |port|
          puts "mongrel_#{port[0]}.value #{port[1]}"
        end

      end
    end

    def get_pids
      h = {}
      pids = []
      pids = `pgrep mongrel_rails`
      pids.each do |p|
        l = `ps #{p}`
        l =~ /-p (\d+)/
        h[p] = Regexp.last_match(1)
      end
      h
    end

    def autoconf
      pids.length > 0
    end
  end
end

mpm = Munin::MongrelProcessMemory.new

case ARGV[0]
when 'config'
  puts 'graph_title Mongrel Memory'
  puts 'graph_vlabel RSS'
  puts 'graph_category memory'
  puts 'graph_args --base 1024 -l 0'
  puts 'graph_scale yes'
  puts 'graph_info Tracks the size of individual mongrel processes'
  mpm.get_pids.values.sort.each do |port|
    puts "mongrel_#{port}.label mongrel_#{port}"
    puts "mongrel_#{port}.info Process memory"
    puts "mongrel_#{port}.type GAUGE"
    puts "mongrel_#{port}.min 0"
  end
when 'autoconf'
  if mpm.autoconf
    puts 'yes'
    exit 0
  end
  puts 'no'
  exit 0
else
  mpm.run
end