Create distribution manager locker with python for redis.

dml.py

import redis
import uuid
import time
import logging

CONN_SETTINGS = {
    'host': 'localhost',
    'port': 6379,
    'db': 0,
}


def get_identifier():
    return str(uuid.uuid4())


class Lock:
    def __init__(self, redis_ins, my_key, identifier, timeout):
        self.redis = redis_ins
        self.timeout = timeout
        self.my_key = my_key
        self.identifier = identifier

    def __enter__(self):
        if self.acquire(timeout):
            return self

    def __exit__(self, exc_type, exc_value, traceback):
        self.release()

    def acquire(self, timeout):
        end = time.time() + timeout
        while end > time.time():
            status = self.redis.setnx(self.my_key, self.identifier)
            if status:
                return True
            time.sleep(0.5)
        assert RuntimeError, logging.debug('Unable to access key')
        return False

    def release(self):
        pipe = redis.pipeline(True)
        pipe.watch(self.my_key)
        while True:
            if pipe.get == self.identifier:
                pipe.multi()
                pipe.delete(self.my_key)
                pipe.execute()
            pipe.unwatch()
            break


if __name__ == '__main__':
    identifier = get_identifier()
    my_key = 'search_something'
    redis = redis.Redis(**CONN_SETTINGS)
    timeout = 10
    locker = Lock(redis, my_key, identifier, timeout)
    with locker:
        time.sleep(10)