daemonize is a library for writing system daemons in Python. It has some bits from daemonize.sourceforge.net. It is distributed under MIT license.

Installation

You can install it from Python Package Index (PyPI):

$ pip install daemonize

Usage

from time import sleep
from daemonize import Daemonize

pid = "/tmp/test.pid"


def main():
    while True:
        sleep(5)

daemon = Daemonize(app="test_app", pid=pid, action=main)
daemon.start()

File descriptors

Daemonize object's constructor understands the optional argument keep_fds which contains a list of FDs which should not be closed. For example:

import logging
from daemonize import Daemonize

pid = "/tmp/test.pid"
logger = logging.getLogger(__name__)
logger.setLevel(logging.DEBUG)
logger.propagate = False
fh = logging.FileHandler("/tmp/test.log", "w")
fh.setLevel(logging.DEBUG)
logger.addHandler(fh)
keep_fds = [fh.stream.fileno()]


def main():
    logger.debug("Test")

daemon = Daemonize(app="test_app", pid=pid, action=main, keep_fds=keep_fds)
daemon.start()