daemonizer-py 1.5.1

Library to define and manage daemonized Python-based programs in programmatic (SDK) or CLI-ready ways

daemonizer

Light-weight and easy-to-use Python package that simplifies the process of daemonizing Python applications, allowing them to run in the background as standalone logics.

Features

• Simple API to daemonize any Python function or class
• Automatic handling of process management (PID files, logging, etc.)
• Support for start, stop, restart, and status operations
• Signal handling (SIGTERM, SIGINT, etc.)
• Compatible with UNIX-like systems
• Python 3.7+ support

Getting started

Install package using uv or pip:

uv add daemonizer-py # pip install daemonizer-py

Create a Python script daemon.py where you can define your daemon logic following below framework:

from datetime import datetime
from time import sleep

from daemonizer.core.daemons.logic import forever_loop
from daemonizer.core.daemons.unix import UNIXDaemon

class SampleDaemon(UNIXDaemon):
    """ Sample daemon """

    @forever_loop(catch_exceptions=False, after_delay=0.01)
    def run(self) -> None:
        with open("/tmp/hello_daemon.log", "a") as f:
            f.write(f"Hello, World {datetime.now()}\n")
            f.write(f"{self.kwargs().get('ssa', None)}\n")
        sleep(1)

Defining a daemon is very simple:

1. Create a subclass of UNIXDaemon
2. Just overload the run(...) method with your logic to be executed in the daemon

[!NOTE] No need to worry about while True: loop. If you decorate the run(...) method with the @forever_loop(...) decorator, the logic defined inside will be executed infinitely.

Optional arguments are available for the @forever_loop(...) decorator. (See docs)

Once defined, you can start a daemon using two methods:

• Using handler func:

if __name__ == "__main__":
    handler(SampleDaemon(name="daemon_1"))

uv run daemon.py [start|stop|restart|status]

• Using context manager handler with DaemonHandler():

from daemonizer.core.handlers.ctx_manager import DaemonHandler
# Daemons handler
with DaemonHandler() as h:
    h.start(SampleDaemon1(name="daemon_1"))
    h.start(SampleDaemon2(name="daemon_2"))

[!WARNING] Daemon should have a unique name at global level (no duplicate).

• Using CLI:

daemonizer start daemon.py # START op will be performed on all daemons defined in this file
daemonizer start daemon.py SampleDaemon1 # START op will be performed **ONLY** on `SampleDaemon1` defined in this file

• Using API or web-app (WIP)

The package provides a simple command-line interface to interact with the daemonized process. The following commands are available:

$ python3 main.py {start,stop,restart,status}

Contribute

Clone the repo, improve the code base and submit a pull request

git clone https://github.com/lcsrodriguez/daemonizer.git
cd daemonizer/
uv sync
pre-commit install-hooks

License

This project is licensed under the MIT License - see the LICENSE file for details.