python守护进程demo

pip install python-daemon

#! /usr/bin/env python
# -*- coding: utf-8 -*-

import logging
import time

# third party libs
from daemon import runner


class Updater():
    def __init__(self):
        self.stdin_path = '/dev/null'
        self.stdout_path = '/dev/tty'
        self.stderr_path = '/dev/tty'
        self.pidfile_path = '/tmp/testdaemon.pid'
        self.pidfile_timeout = 5

    def run(self):
        while True:
            # Main code goes here ...
            # Note that logger level needs to be set to logging.DEBUG before this shows up in the logs
            logger.debug("Debug message")
            logger.info("Info message")
            logger.warn("Warning message")
            logger.error("Error message")
            time.sleep(10)


app = Updater()
logger = logging.getLogger("DaemonLog")
logger.setLevel(logging.INFO)
formatter = logging.Formatter("%(asctime)s - %(name)s - %(levelname)s - %(message)s")
handler = logging.FileHandler("/tmp/testdaemon.log")
handler.setFormatter(formatter)
logger.addHandler(handler)

daemon_runner = runner.DaemonRunner(app)

# This ensures that the logger file handle does not get closed during daemonization
daemon_runner.daemon_context.files_preserve = [handler.stream]
daemon_runner.do_action()

#!/usr/bin/env python

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/null', stdout='/dev/null', stderr='/dev/null'):
        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().
        """

#!/usr/bin/env python

import sys, time
from daemon import Daemon


class MyDaemon(Daemon):
    def run(self):
        while True:
            time.sleep(1)


if __name__ == "__main__":
    daemon = MyDaemon('/tmp/daemon-example.pid')
    if len(sys.argv) == 2:
        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)

"""Generic linux daemon base class for python 3.x."""

import sys, os, time, atexit, signal

class daemon:
	"""A generic daemon class.

	Usage: subclass the daemon class and override the run() method."""

	def __init__(self, pidfile): self.pidfile = pidfile
	
	def daemonize(self):
		"""Deamonize class. UNIX double fork mechanism."""

		try: 
			pid = os.fork() 
			if pid > 0:
				# exit first parent
				sys.exit(0) 
		except OSError as err: 
			sys.stderr.write('fork #1 failed: {0}\n'.format(err))
			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 as err: 
			sys.stderr.write('fork #2 failed: {0}\n'.format(err))
			sys.exit(1) 
	
		# redirect standard file descriptors
		sys.stdout.flush()
		sys.stderr.flush()
		si = open(os.devnull, 'r')
		so = open(os.devnull, 'a+')
		se = open(os.devnull, 'a+')

		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())
		with open(self.pidfile,'w+') as f:
			f.write(pid + '\n')
	
	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:
			with open(self.pidfile,'r') as pf:

				pid = int(pf.read().strip())
		except IOError:
			pid = None
	
		if pid:
			message = "pidfile {0} already exist. " + \
					"Daemon already running?\n"
			sys.stderr.write(message.format(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:
			with open(self.pidfile,'r') as pf:
				pid = int(pf.read().strip())
		except IOError:
			pid = None
	
		if not pid:
			message = "pidfile {0} does not exist. " + \
					"Daemon not running?\n"
			sys.stderr.write(message.format(self.pidfile))
			return # not an error in a restart

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