[mod] migrate from Redis to Valkey (#4795)

This patch migrates from `redis==5.2.1` [1] to `valkey==6.1.0` [2].

The migration to valkey is necessary because the company behind Redis has decided
to abandon the open source license. After experiencing a drop in user numbers,
they now want to run it under a dual license again. But this move demonstrates
once again how unreliable the company is and how it treats open source
developers.

To review first, read the docs::

    $ make docs.live

Follow the instructions to remove redis:

- http://0.0.0.0:8000/admin/settings/settings_redis.html

Config and install a local valkey DB:

- http://0.0.0.0:8000/admin/settings/settings_valkey.html

[1] https://pypi.org/project/redis/
[2] https://pypi.org/project/valkey/

Co-authored-by: HLFH <gaspard@dhautefeuille.eu>
Co-authored-by: Markus Heiser <markus.heiser@darmarit.de>

1 files changed, 0 insertions, 69 deletions

diff --git a/searx/redisdb.py b/searx/redisdb.py
deleted file mode 100644
index bed0c347b..000000000
--- a/searx/redisdb.py
+++ /dev/null
@@ -1,69 +0,0 @@
-# SPDX-License-Identifier: AGPL-3.0-or-later
-"""Implementation of the redis client (redis-py_).
-
-.. _redis-py: https://github.com/redis/redis-py
-
-This implementation uses the :ref:`settings redis` setup from ``settings.yml``.
-A redis DB connect can be tested by::
-
-  >>> from searx import redisdb
-  >>> redisdb.initialize()
-  True
-  >>> db = redisdb.client()
-  >>> db.set("foo", "bar")
-  True
-  >>> db.get("foo")
-  b'bar'
-  >>>
-
-"""
-
-import os
-import pwd
-import logging
-import redis
-from searx import get_setting
-
-
-OLD_REDIS_URL_DEFAULT_URL = 'unix:///usr/local/searxng-redis/run/redis.sock?db=0'
-"""This was the default Redis URL in settings.yml."""
-
-_CLIENT = None
-logger = logging.getLogger(__name__)
-
-
-def client() -> redis.Redis:
-    return _CLIENT
-
-
-def initialize():
-    global _CLIENT  # pylint: disable=global-statement
-    redis_url = get_setting('redis.url')
-    if not redis_url:
-        return False
-    try:
-        # create a client, but no connection is done
-        _CLIENT = redis.Redis.from_url(redis_url)
-
-        # log the parameters as seen by the redis lib, without the password
-        kwargs = _CLIENT.get_connection_kwargs().copy()
-        kwargs.pop('password', None)
-        kwargs = ' '.join([f'{k}={v!r}' for k, v in kwargs.items()])
-        logger.info("connecting to Redis %s", kwargs)
-
-        # check the connection
-        _CLIENT.ping()
-
-        # no error: the redis connection is working
-        logger.info("connected to Redis")
-        return True
-    except redis.exceptions.RedisError as e:
-        _CLIENT = None
-        _pw = pwd.getpwuid(os.getuid())
-        logger.exception("[%s (%s)] can't connect redis DB ...", _pw.pw_name, _pw.pw_uid)
-        if redis_url == OLD_REDIS_URL_DEFAULT_URL and isinstance(e, redis.exceptions.ConnectionError):
-            logger.info(
-                "You can safely ignore the above Redis error if you don't use Redis. "
-                "You can remove this error by setting redis.url to false in your settings.yml."
-            )
-    return False