#!/usr/bin/env ruby

require 'rubygems'
require 'daemons'


options = {}
options[:log_output] = true
options[:dir] = File.expand_path('../../log/', __FILE__)
options[:dir_mode] = :normal

Daemons.run_proc('PassengerMonitor', options) do

  command = 'sudo passenger-memory-stats'
  memory_limit = 250

  def running?(pid)
    begin
      return Process.getpgid(pid) != -1
    rescue Errno::ESRCH
      return false
   end
  end

  loop do
    `#{command}`.each_line do |line|
      next unless /(\d+)\s+\d+\s+(\d+\.\d+)\s+MB\s+(\d+\.\d+)\s+MB\s+Rails:/.match(line)
      all, pid, vm_size, private = $~.to_a
      if private.to_i > memory_limit
        puts "#{Time.now}: Killing #{pid}, memory usage == #{private}"
        Process.kill("SIGUSR1", pid.to_i)
        puts "Finished kill attempt. Sleeping for 20 seconds to give it time to die..."
        sleep 20
        if running?(pid.to_i)
          puts "Process is still running - die bitch"
          Process.kill("KILL", pid.to_i)
        end
      else
        puts "Process ##{pid} is not above limit (#{private}MB)"
      end
      sleep 120
    end
  end

end