Question

我有循环的python应用程序，它生成一些文件，保存视频图像和其他一些东西。我在Fedora（17）PC上安装它并希望它“永远”运行，即如果它挂起（我可以在循环中放入一些keep_alive文件） - 它应该重新启动。它也应该在重启时启动。据我所知，python-daemon有助于做到这一点，并在Fedora中进行systemd。我有systemd的以下配置文件（我不确定某些参数，因为文档对于我的linux知识水平来说太复杂了）：

[Unit]
Description=TPR Daemon

[Service]
Type=forking
Restart=always
WorkingDirectory=/home/igor/tpr
PIDFile=/var/run/tpr.pid
ExecStart=/usr/bin/python /home/igor/tpr/testd.py

[Install]
WantedBy=default.target

这是我的testd.py：

import daemon
import time, sys

class MyDaemon(object):
    def __init__(self):
        pass

    def run(self):
        while True:
            print 'I am alive!'
            time.sleep(1)

if __name__ == '__main__':
    with daemon.DaemonContext(stdout=sys.stdout):
        check = MyDaemon()
        check.run()

当我使用“sudo systemctl start tpr.service”运行它时，它会暂停一段时间，然后用这个meesage取消：

警告：tpr.service的单元文件在磁盘上已更改，建议使用'systemctl --system daemon-reload'。 tpr.service的作业失败。有关详细信息，请参阅“systemctl status tpr.service”和“journalctl -xn”。

以下是来自/ var / log / messages的一些日志：

Aug  9 21:32:27 localhost systemd[1]: Unit tpr.service entered failed state.
Aug  9 21:32:27 localhost systemd[1]: tpr.service holdoff time over, scheduling restart.
Aug  9 21:32:27 localhost systemd[1]: Stopping TPR Daemon...
Aug  9 21:32:27 localhost systemd[1]: Starting TPR Daemon...
Aug  9 21:33:57 localhost systemd[1]: tpr.service operation timed out. Terminating.
Aug  9 21:33:57 localhost python[28702]: I am alive!
Aug  9 21:33:57 localhost python[28702]: I am alive!
Aug  9 21:33:57 localhost python[28702]: I am alive!
Aug  9 21:33:57 localhost python[28702]: I am alive!
...
Aug  9 21:33:57 localhost python[28702]: I am alive!
Aug  9 21:33:57 localhost python[28702]: I am alive!
Aug  9 21:33:57 localhost python[28702]: I am alive!
Aug  9 21:33:57 localhost python[28702]: I am alive!
Aug  9 21:33:57 localhost systemd[1]: tpr.service: control process exited, code=exited status=1
Aug  9 21:33:57 localhost systemd[1]: Failed to start TPR Daemon.
Aug  9 21:33:57 localhost systemd[1]: Unit tpr.service entered failed state.
Aug  9 21:33:57 localhost systemd[1]: tpr.service holdoff time over, scheduling restart.
Aug  9 21:33:57 localhost systemd[1]: Stopping TPR Daemon...
Aug  9 21:33:57 localhost systemd[1]: Starting TPR Daemon...

所以它应该运行，但是这个错误是什么？也许有一些简单方便的方法来完成我的任务，我发明了自行车？

更新

似乎守护进程应该以某种方式让systemd知道它已经开始......但是如何？

Aug 10 01:15:36 localhost systemd[1]: Starting TPR Daemon...
Aug 10 01:17:06 localhost systemd[1]: tpr.service operation timed out. Terminating.
Aug 10 01:17:06 localhost systemd[1]: tpr.service: control process exited, code=exited status=1
Aug 10 01:17:06 localhost systemd[1]: Failed to start TPR Daemon.
Aug 10 01:17:06 localhost systemd[1]: Unit tpr.service entered failed state.
Aug 10 01:17:06 localhost systemd[1]: tpr.service holdoff time over, scheduling restart.
Aug 10 01:17:06 localhost systemd[1]: Stopping TPR Daemon...
Aug 10 01:17:06 localhost systemd[1]: Starting TPR Daemon...
Aug 10 01:18:36 localhost systemd[1]: tpr.service operation timed out. Terminating.
Aug 10 01:18:36 localhost systemd[1]: tpr.service: control process exited, code=exited status=1
Aug 10 01:18:36 localhost systemd[1]: Failed to start TPR Daemon.
Aug 10 01:18:36 localhost systemd[1]: Unit tpr.service entered failed state.
Aug 10 01:18:36 localhost systemd[1]: tpr.service holdoff time over, scheduling restart.
Aug 10 01:18:36 localhost systemd[1]: Stopping TPR Daemon...
Aug 10 01:18:36 localhost systemd[1]: Starting TPR Daemon...

Answer 1

有关更改磁盘的错误意味着文件已更改。运行systemctl daemon-reload后，将重新读取该文件，并且您将能够启动该服务。您可以使用this manual pages中所述的通知。服务的类型是notify。接下来是：您将服务类型称为forking。你的流程真的有问题吗？如果您使用分叉，建议设置PIDfile选项。使用systemd，没有必要将进程分叉为守护进程。

python app（守护进程）和systemd fedora

1 个答案: