使Ruby程序成为守护进程？

Question

我想写一个Ruby程序，它总是在我的Mac上的后台运行（守护进程）。

有人能指出我如何做到这一点的正确方向吗？

Answer 1

使用Daemonize.rb

require 'daemons' 
Daemons.daemonize 

很简单的例子：http://github.com/utkarsh2012/backitup/blob/master/backitup.rb

如何安装守护宝石：

gem install daemons 

Answer 2

这是一个module来守护您的代码。这是一个包含现有脚本的offshoot。

本质上，它归结为这个（特拉维斯威顿的Daemonize.rb，上面的第一个环节，修改了某些程序我前写的年龄）：

private 
# This method causes the current running process to become a daemon 
# If closefd is true, all existing file descriptors are closed 
def daemonize(pathStdErr, oldmode=0, closefd=false) 
    srand # Split rand streams between spawning and daemonized process 
    safefork and exit# Fork and exit from the parent 

    # Detach from the controlling terminal 
    unless sess_id = Process.setsid 
     raise 'Cannot detach from controlled terminal' 
    end 

    # Prevent the possibility of acquiring a controlling terminal 
    if oldmode.zero? 
     trap 'SIGHUP', 'IGNORE' 
     exit if pid = safefork 
    end 

    Dir.chdir "/" # Release old working directory 
    File.umask 0000 # Insure sensible umask 

    if closefd 
     # Make sure all file descriptors are closed 
     ObjectSpace.each_object(IO) do |io| 
      unless [STDIN, STDOUT, STDERR].include?(io) 
       io.close rescue nil 
      end 
     end 
    end 

    STDIN.reopen "/dev/null"  # Free file descriptors and 
    STDOUT.reopen "/dev/null" # point them somewhere sensible 
    STDERR.reopen pathStdErr, "w"   # STDOUT/STDERR should go to a logfile 
    return oldmode ? sess_id : 0 # Return value is mostly irrelevant 
end 

# Try to fork if at all possible retrying every 5 sec if the 
# maximum process limit for the system has been reached 
def safefork 
    tryagain = true 
    while tryagain 
     tryagain = false 
     begin 
      if pid = fork 
       return pid 
      end 
     rescue Errno::EWOULDBLOCK 
      sleep 5 
      tryagain = true 
     end 
    end 
end 

Answer 3

啊，谷歌来救援！退房

http://fitzgeraldsteele.wordpress.com/2009/05/04/launchd-example-start-web-server-at-boot-time/

其中一个有用的博客提供写的launchd plist中推出了红宝石的Web应用程序服务器的一个例子。

Answer 4

的Ruby 1.9.x的已执行以下操作：

Process.daemon 

把它放在你的代码中，就是这样。

来自“Daemon Processes in Ruby”。

Answer 5

需要看到后台程序导轨宝石为Rails 3（基于rails_generator）：

https://github.com/mirasrael/daemons-rails

可以生成守护存根这样的：

rails generate daemon <name> 

特点：

• individual con每个守护特伦脚本
• 耙：每守护守护命令
• Capistrano的友好
• 应用范围的控制脚本
• 监测API
• 可能多个后台程序设置