Creazione del daemon python 2.7 con pep-3143

Question

Qualcuno sa come implementare python 2.7 come un daemon Linux? Sto cercando un esempio funzionante con argomenti start/stop.

Answer 1

Questo seguente codice è un esempio di come creare un demone utilizzando python su linux, se non ho risposto alla tua domanda si dovrebbe guardare questo link http://ridingpython.blogspot.com.br/2011/08/turning-your-python-script-into-linux.html

main.py

import sys 
from daemon import Daemon 

class MyDaemon(Daemon): 
    def run(self): 
     print 'working' 

if __name__ == "__main__": 
    daemon = MyDaemon('/tmp/HMTd.pid') 
    if len(sys.argv) > 1: 
     if 'start' == sys.argv[1]: 
      daemon.start() 
     elif 'stop' == sys.argv[1]: 
      daemon.stop() 
     elif 'restart' == sys.argv[1]: 
      daemon.restart() 
     else: 
      print "Unknown command" 
      sys.exit(2) 
     sys.exit(0) 
    else: 
     print "usage: %s start|stop|restart" % sys.argv[0] 
     sys.exit(2) 

classe daemon.py

import sys, os, time, atexit 
from signal import SIGTERM 

class Daemon: 
    """ 
    A generic daemon class. 

    Usage: subclass the Daemon class and override the run() method 
    """ 
    def __init__(self, pidfile, stdin='/dev/stdin', stdout='/dev/stdout', stderr='/dev/stderr'): 
     self.stdin = stdin 
     self.stdout = stdout 
     self.stderr = stderr 
     self.pidfile = pidfile 

    def daemonize(self): 
     """ 
     do the UNIX double-fork magic, see Stevens' "Advanced 
     Programming in the UNIX Environment" for details (ISBN 0201563177) 
     http://www.erlenstar.demon.co.uk/unix/faq_2.html#SEC16 
     """ 
     try: 
      pid = os.fork() 
      if pid > 0: 
       # exit first parent 
       sys.exit(0) 
     except OSError, e: 
      sys.stderr.write("fork #1 failed: %d (%s)\n" % (e.errno, e.strerror)) 
      sys.exit(1) 

     # decouple from parent environment 
     os.chdir("/") 
     os.setsid() 
     os.umask(0) 

     # do second fork 
     try: 
      pid = os.fork() 
      if pid > 0: 
       # exit from second parent 
       sys.exit(0) 
     except OSError, e: 
      sys.stderr.write("fork #2 failed: %d (%s)\n" % (e.errno, e.strerror)) 
      sys.exit(1) 

     # redirect standard file descriptors 
     sys.stdout.flush() 
     sys.stderr.flush() 
     si = file(self.stdin, 'r') 
     so = file(self.stdout, 'a+') 
     se = file(self.stderr, 'a+', 0) 
     os.dup2(si.fileno(), sys.stdin.fileno()) 
     os.dup2(so.fileno(), sys.stdout.fileno()) 
     os.dup2(se.fileno(), sys.stderr.fileno()) 

     # write pidfile 
     atexit.register(self.delpid) 
     pid = str(os.getpid()) 
     file(self.pidfile,'w+').write("%s\n" % pid) 

    def delpid(self): 
     os.remove(self.pidfile) 

    def start(self): 
     """ 
     Start the daemon 
     """ 
     # Check for a pidfile to see if the daemon already runs 
     try: 
      pf = file(self.pidfile,'r') 
      pid = int(pf.read().strip()) 
      pf.close() 
     except IOError: 
      pid = None 

     if pid: 
      message = "pidfile %s already exist. Daemon already running?\n" 
      sys.stderr.write(message % self.pidfile) 
      sys.exit(1) 

     # Start the daemon 
     self.daemonize() 
     self.run() 

    def stop(self): 
     """ 
     Stop the daemon 
     """ 
     # Get the pid from the pidfile 
     try: 
      pf = file(self.pidfile,'r') 
      pid = int(pf.read().strip()) 
      pf.close() 
     except IOError: 
      pid = None 

     if not pid: 
      message = "pidfile %s does not exist. Daemon not running?\n" 
      sys.stderr.write(message % self.pidfile) 
      return # not an error in a restart 

     # Try killing the daemon process  
     try: 
      while 1: 
       os.kill(pid, SIGTERM) 
       time.sleep(0.1) 
     except OSError, err: 
      err = str(err) 
      if err.find("No such process") > 0: 
       if os.path.exists(self.pidfile): 
        os.remove(self.pidfile) 
      else: 
       print str(err) 
       sys.exit(1) 

    def restart(self): 
     """ 
     Restart the daemon 
     """ 
     self.stop() 
     self.start() 

    def run(self): 
     """ 
     You should override this method when you subclass Daemon. It will be called after the process has been 
     daemonized by start() or restart(). 
     """