[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, 99 deletions

diff --git a/searx/engines/redis_server.py b/searx/engines/redis_server.py
deleted file mode 100644
index eebb5809b..000000000
--- a/searx/engines/redis_server.py
+++ /dev/null
@@ -1,99 +0,0 @@
-# SPDX-License-Identifier: AGPL-3.0-or-later
-"""Redis is an open source (BSD licensed), in-memory data structure (key value
-based) store.  Before configuring the ``redis_server`` engine, you must install
-the dependency redis_.
-
-Configuration
-=============
-
-Select a database to search in and set its index in the option ``db``.  You can
-either look for exact matches or use partial keywords to find what you are
-looking for by configuring ``exact_match_only``.
-
-Example
-=======
-
-Below is an example configuration:
-
-.. code:: yaml
-
-  # Required dependency: redis
-
-  - name: myredis
-    shortcut : rds
-    engine: redis_server
-    exact_match_only: false
-    host: '127.0.0.1'
-    port: 6379
-    enable_http: true
-    password: ''
-    db: 0
-
-Implementations
-===============
-
-"""
-
-import redis  # pylint: disable=import-error
-
-from searx.result_types import EngineResults
-
-engine_type = 'offline'
-
-# redis connection variables
-host = '127.0.0.1'
-port = 6379
-password = ''
-db = 0
-
-# engine specific variables
-paging = False
-exact_match_only = True
-
-_redis_client = None
-
-
-def init(_engine_settings):
-    global _redis_client  # pylint: disable=global-statement
-    _redis_client = redis.StrictRedis(
-        host=host,
-        port=port,
-        db=db,
-        password=password or None,
-        decode_responses=True,
-    )
-
-
-def search(query, _params) -> EngineResults:
-    res = EngineResults()
-
-    if not exact_match_only:
-        for kvmap in search_keys(query):
-            res.add(res.types.KeyValue(kvmap=kvmap))
-        return res
-
-    kvmap: dict[str, str] = _redis_client.hgetall(query)
-    if kvmap:
-        res.add(res.types.KeyValue(kvmap=kvmap))
-    elif " " in query:
-        qset, rest = query.split(" ", 1)
-        for row in _redis_client.hscan_iter(qset, match='*{}*'.format(rest)):
-            res.add(res.types.KeyValue(kvmap={row[0]: row[1]}))
-    return res
-
-
-def search_keys(query) -> list[dict]:
-    ret = []
-    for key in _redis_client.scan_iter(match='*{}*'.format(query)):
-        key_type = _redis_client.type(key)
-        res = None
-
-        if key_type == 'hash':
-            res = _redis_client.hgetall(key)
-        elif key_type == 'list':
-            res = dict(enumerate(_redis_client.lrange(key, 0, -1)))
-
-        if res:
-            res['redis_key'] = key
-            ret.append(res)
-    return ret