delayed_job_singleton.rb

#!/usr/bin/env ruby

PRESUMPTIVE_RAILS_ROOT = "/data/[APP_NAME]/current"
LOG_PATH = "/data/[APP_NAME]/shared/log/delayed_job_singleton.log"

Dir.chdir PRESUMPTIVE_RAILS_ROOT

require 'home_run'
require "rubygems"
require "bundler/setup"
require 'daemon_spawn'

class DelayedJobSingleton < DaemonSpawn::Base
  def start(args)
    require "/data/[APP_NAME]/current/config/environment.rb"
    f = open LOG_PATH, (File::WRONLY | File::APPEND | File::CREAT)
    f.sync = true
    RAILS_DEFAULT_LOGGER.auto_flushing = true
    RAILS_DEFAULT_LOGGER.instance_variable_set(:@log, f)
    Delayed::Worker.logger = RAILS_DEFAULT_LOGGER
    Delayed::Worker.new(:quiet => true).start
  end

  def stop
  end
end

DelayedJobSingleton.spawn!(:log_file => LOG_PATH,
                           :pid_file => "/data/[APP_NAME]/shared/pids/delayed_job_singleton.pid",
                           :sync_log => true,
                           :working_dir => PRESUMPTIVE_RAILS_ROOT,
                           :singleton => true,
                           :timeout => 90,
                           :signal => 'INT')