python - crontab python子进程和服务重启

Question

我有一个小的 python 代码，可以在它不存在时重新启动 nginx。当我运行 sudo python monitor_server.py 时一切正常。当我尝试使用 root cron (sudo crontab -e) 对其进行 cron 时:
* * * * * python/root/monitor_server.py >/var/log/my_monitor/cron_log.log 2>&1我得到:

Traceback (most recent call last):
  File "/root/monitor_server.py", line 19, in <module>
    restart_service('mongod')
  File "/root/monitor_server.py", line 10, in restart_service
    subprocess.call(command, shell=False)
  File "/usr/lib64/python2.6/subprocess.py", line 478, in call
    p = Popen(*popenargs, **kwargs)
  File "/usr/lib64/python2.6/subprocess.py", line 642, in __init__
    errread, errwrite)
  File "/usr/lib64/python2.6/subprocess.py", line 1234, in _execute_child
    raise child_exception
OSError: [Errno 2] No such file or directory

代码:

def restart_service(name):
    command = ['service', name, 'restart'];
    #shell=FALSE for sudo to work.
    subprocess.call(command, shell=False)

if __name__ == '__main__':
    try:
        f = urllib2.urlopen("<healthcheck URL>")
    except (urllib2.HTTPError, urllib2.URLError) as e:
        logging.log(logging.ERROR, 'restarting server')
        restart_service('nginx')

Answer 1

尝试使用绝对路径调用命令，因为您在没有shell和另一个用户帐户下调用它，如果不指定绝对路径，某些命令将无法使用。

首先找到，命令所在位置:

$ which service
/usr/sbin/service

然后将您的代码更改为:

def restart_service(name):
    command = ['/usr/sbin/service', name, 'restart'];
    #shell=FALSE for sudo to work.
    subprocess.call(command, shell=False)