mirror of
https://github.com/Pardus-LiderAhenk/ahenk
synced 2024-12-12 10:22:15 +03:00
138 lines
3.7 KiB
Python
138 lines
3.7 KiB
Python
#!/usr/bin/env python3
|
|
import atexit
|
|
import os
|
|
import sys
|
|
import time
|
|
from signal import SIGTERM
|
|
|
|
|
|
class BaseDaemon(object):
|
|
"""
|
|
A generic daemon class.
|
|
|
|
Usage: subclass the Daemon class and override the run() method
|
|
"""
|
|
|
|
startmsg = 'started with pid %s'
|
|
|
|
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 as 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 as e:
|
|
sys.stderr.write("fork #2 failed: %d (%s)\n" % (e.errno, e.strerror))
|
|
sys.exit(1)
|
|
|
|
# redirect standard file descriptors
|
|
si = open(self.stdin, 'r')
|
|
so = open(self.stdout, 'a+')
|
|
se = open(self.stderr, 'a+')
|
|
|
|
pid = str(os.getpid())
|
|
|
|
sys.stderr.write("\n%s\n" % self.startmsg % pid)
|
|
sys.stderr.flush()
|
|
|
|
if self.pidfile:
|
|
open(self.pidfile, 'w+').write("%s\n" % pid)
|
|
|
|
atexit.register(self.delpid)
|
|
os.dup2(si.fileno(), sys.stdin.fileno())
|
|
os.dup2(so.fileno(), sys.stdout.fileno())
|
|
os.dup2(se.fileno(), sys.stderr.fileno())
|
|
|
|
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 = open(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 = open(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 as 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().
|
|
"""
|