Resque restart when a file is touched ( like passenger restart )

gistfile1.txt

# Can't remember where I found this, backing it up here.

# Use bottom script like so
#      on.condition(:restart_file_touched) do |c|
#        c.interval = 5.seconds
#        c.restart_file = File.join(rails_root, 'tmp', 'restart.txt')
#      end

# restart.god
module God
  module Conditions
    class RestartFileTouched < PollCondition
      attr_accessor :restart_file
      def initialize
        super
      end

      def process_start_time
        tmp = Time.parse(`ps -o lstart -p #{self.watch.pid} --no-heading`)
	puts "Process time: #{tmp}" 
	tmp
      end

      def restart_file_modification_time
        tmp = File.mtime(self.restart_file)
	puts "Restart file:#{self.restart_file}  #{tmp}" 
	tmp
      end

      def valid?
        valid = true
        valid &= complain("Attribute 'restart_file' must be specified", self) if self.restart_file.nil?
        valid
      end
                        
      def test
        process_start_time < restart_file_modification_time
      end
    end
  end
end


#Example resque.god that uses restart

rails_env = ENV['RAILS_ENV'] || "production"
rails_root = ENV['RAILS_ROOT'] 
num_workers = rails_env == 'production' ? 2 : 1

num_workers.times do |num|
  God.watch do |w|
    w.dir = "#{rails_root}"
    w.name = "resque-#{num}"
    w.group = 'resque'
    w.interval = 30.seconds
    w.env = {"QUEUE"=>"*", "RAILS_ENV"=>rails_env}
    w.start = "/usr/local/rvm/gems/ruby-1.9.2-p290/bin/bundle exec rake -f #{rails_root}/Rakefile environment resque:work"

    w.uid = 'user'
    w.gid = 'user'

    # restart if memory gets too high
    w.transition(:up, :restart) do |on|
      on.condition(:memory_usage) do |c|
        c.above = 350.megabytes
        c.times = 2
      end
 
      on.condition(:restart_file_touched) do |c|
        c.interval = 5.seconds
        c.restart_file = File.join(rails_root, 'tmp', 'restart.txt')
      end

    end

    # determine the state on startup
    w.transition(:init, { true => :up, false => :start }) do |on|
      on.condition(:process_running) do |c|
        c.running = true
      end
    end

    # determine when process has finished starting
    w.transition([:start, :restart], :up) do |on|
      on.condition(:process_running) do |c|
        c.running = true
        c.interval = 5.seconds
      end

      # failsafe
      on.condition(:tries) do |c|
        c.times = 5
        c.transition = :start
        c.interval = 5.seconds
      end
    end

    # start if process is not running
    w.transition(:up, :start) do |on|
      on.condition(:process_running) do |c|
        c.running = false
      end
    end
  end
end