DDuarte/django-zk-locks

Distributed locks for Django using Zookeeper

django-zk-locks

Distributed locks for Django using Zookeeper

Installation

pip install django-zk-locks

Usage

django-zk-locks exposes one single the lock contextmanager and the locked decorator.

The locked decorator will wrap a django management command (subclasses of django.core.management.base.BaseCommand) or any function with the lock contextmanager:

from django.core.management.base import BaseCommand

from database_locks import locked

@locked
class Command(BaseCommand):
    ...
    def handle(self, *args, **options):
        self.stdout.write('Got the lock')

from database_locks import locked

class SomeClass:
  def non_locked(self):
    pass

  @locked
  def locked(self):
    print('got lock')

from database_locks import lock

class SomeClass:
  def non_locked(self):
    pass

  def locked(self):
    with lock():
        print('got lock')

Docs

Both lock and locked have the same optional args:

:param lock_name: unique name in DB for this function

There are also the following options you can specify in the project settings.py

• ZOOKEEPER_LOCKS_STATUS_FILE: file that will be updated with the lock status (default None). Useful when you have multiple shared-lock processes, to quickly inspect which one has the lock.
• ZOOKEEPER_LOCKS_ENABLED: set to False to globally disable locks (default True)
• ZOOKEEPER_LOCKS_HOSTS: connection string for Zookeeper, such as "localhost:2181,localhost:2182,localhost:2183"

Testing

Tox is used by the Github Action to test several python and django versions.

To quickly test locally, kick off a Zookeeper docker container:

docker run -d --name locks-test

-p 2181:2181 zookeeper:3.9

List available environments with tox -l and then run the one you want/have:

tox -e py310-dj42