Customizable prefix

[Mogost]

Hi. Faced with something similar to #10

I have shared Redis cache, and control access with ACL.
To separate instances I use prefixes but python-redis-lock overwrites my prefix with lock:

python-redis-lock/src/redis_lock/__init__.py

Line 162 in 1497012

self._name = 'lock:' + name

So I get an access error:

NoPermissionError
this user has no permissions to access one of the keys used as arguments

Could we have a customizable prefix for this case?

[ionelmc]

You could subclass and do something like:

class PrefixedLock(Lock):
     def __init__(self, redis_client, prefix, name, **kwargs):
        super().__init__(redis_client, name, **kwargs)
        self._name = f'{prefix}:lock:{name}'
        self._signal = f'{prefix}:lock-signal:{name}' 

[Mogost]

Yep. But it looks like a dirty solution.
For example in this case I also need to fix this part

python-redis-lock/src/redis_lock/__init__.py

Line 52 in 1497012

local locks = redis.call('keys', 'lock:*')

And it all looks like I want to hack python-redis-lock

[ionelmc]

Perhaps a key template argument could be added through all the clases/functions. Eg:

Lock(key_template={'lock': 'lock:{}', 'signal': 'lock-signal:{}'})
reset_all(key_template={'lock': 'lock:{}', 'signal': 'lock-signal:{}'})

But I do want to switch to redis functions (redis>=7) for the next release if I get to do one, so there's that...

[OJFord]

If you construct it with a given client I think it's surprising & potentially harmful to override the key_prefix, or anything really.

For example, I've run into this because my prefix contains a hash tag, and I'm unexpectedly getting an error on lock release because it's overridden that, and so the lock:... & lock-signal:... keys it tries to delete together are hashing to different slots.

Maybe this is well-documented, I just didn't think to look - 'principle of least surprise' and all that.