the callback for `CLUSTER GETKEYSINSLOT` does not work in redis 3+

Hiya,

Here’s some code to illustrate the issue:

>>> from rediscluster import StrictRedisCluster
>>> startup_nodes = [{'host': '127.0.0.1', 'port': 2951}]
>>> rc = StrictRedisCluster(startup_nodes=startup_nodes)
>>> rc.CLUSTER_COMMANDS_RESPONSE_CALLBACKS['CLUSTER GETKEYSINSLOT']
int
>>> rc.execute_command('CLUSTER GETKEYSINSLOT', 601, 2)
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-5-2ad54da2b333> in <module>()
----> 1 rc.execute_command('CLUSTER GETKEYSINSLOT', 601, 2)
...
...
...
venv/lib/python3.6/site-packages/redis/client.py in parse_response(self, connection, command_name, **options)
    585         response = connection.read_response()
    586         if command_name in self.response_callbacks:
--> 587             return self.response_callbacks[command_name](response, **options)
    588         return response
    589

TypeError: int() argument must be a string, a bytes-like object or a number, not 'list'

After applying this diff:

(venv) lcarvalh-ld ~/src/redis-py-cluster git:unstable ± ❱❱❱ git diff
diff --git a/rediscluster/client.py b/rediscluster/client.py
index d0258c3..8f77925 100644
--- a/rediscluster/client.py
+++ b/rediscluster/client.py
@@ -108,7 +108,7 @@ class StrictRedisCluster(StrictRedis):
         'CLUSTER DELSLOTS': bool_ok,
         'CLUSTER FAILOVER': bool_ok,
         'CLUSTER FORGET': bool_ok,
-        'CLUSTER GETKEYSINSLOT': int,
+        'CLUSTER GETKEYSINSLOT': list,
         'CLUSTER INFO': parse_info,
         'CLUSTER KEYSLOT': int,
         'CLUSTER MEET': bool_ok,

The command now returns a list of bytestring keys:

>>> from rediscluster import StrictRedisCluster
>>> startup_nodes = [{'host': '10.136.208.61', 'port': 2951}]
>>> rc = StrictRedisCluster(startup_nodes=startup_nodes)
>>> rc.CLUSTER_COMMANDS_RESPONSE_CALLBACKS['CLUSTER GETKEYSINSLOT']
list
>>> rc.execute_command('CLUSTER GETKEYSINSLOT', 601, 1)
[b'prod.tag_hosts:ROUTER_MT-LD-2']

Happy to submit a PR, but I presume that just a list of raw bytes it not ideal, based on the existence of parse_cluster_nodes and parse_cluster_slots. What would you prefer? A simple function that parses each key would satisfy my personal needs (and I’ve subclassed StrictRedisCluster to do this:

class RedisCluster(StrictRedisCluster):
    def __init__(self, *args, **kwargs) -> None:
        """Create a RedisCluster."""
        # fix getkeysinslot callback
        self.CLUSTER_COMMANDS_RESPONSE_CALLBACKS['CLUSTER GETKEYSINSLOT'] = lambda x: [nativestr(i) for i in x]
        super().__init__(*args, **kwargs)

Thanks in advance for looking!

reference: https://redis.io/commands/cluster-getkeysinslot

[Grokzen]

Have a look at this commit https://github.com/Grokzen/redis-py-cluster/commit/2cbe4a5ba859571e1acb86f33f202904a4d18cb1 it should clear up everything for your problem. Also there is a nice new method that you can use instead of the execute_command solution.

[lorencarvalho]

awesome!! thanks so much