参考此链接，在服务器启动时自动运行延迟作业，而无需在控制台上手动运行rake作业：work
Start or ensure that Delayed Job runs when an application/server restarts
注意：deamons gem不适用于windows，但同样可以在Linux或mac上运行
或
将代码复制到initializers/delayed_job_config.rb中

DELAYED_JOB_PID_PATH = "#{Rails.root}/tmp/pids/delayed_job.pid"

def start_delayed_job
  Thread.new do
    `ruby bin/delayed_job start`
  end
end

def daemon_is_running?
  pid = File.read(DELAYED_JOB_PID_PATH).strip
  Process.kill(0, pid.to_i)
  true
rescue Errno::ENOENT, Errno::ESRCH   # file or process not found
  false
end

start_delayed_job unless daemon_is_running?