[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>

16 files changed, 116 insertions, 87 deletions

diff --git a/docs/admin/arch_public.dot b/docs/admin/arch_public.dot
index 49b03d157..c131186d0 100644
--- a/docs/admin/arch_public.dot
+++ b/docs/admin/arch_public.dot
@@ -7,7 +7,8 @@ digraph G {
   rp      [label="reverse proxy"];
   static  [label="static files", shape=folder, href="url to configure static files", fillcolor=lightgray];
   uwsgi   [label="uwsgi", shape=parallelogram href="https://docs.searxng.org/utils/searxng.sh.html"]
-  redis     [label="redis DB", shape=cylinder];
+  valkey  [label="valkey DB", shape=cylinder];
+
   searxng1  [label="SearXNG #1", fontcolor=blue3];
   searxng2  [label="SearXNG #2", fontcolor=blue3];
   searxng3  [label="SearXNG #3", fontcolor=blue3];
@@ -21,10 +22,10 @@ digraph G {
       { rank=same; static rp };
       rp -> static  [label="optional: reverse proxy serves static files", fillcolor=slategray, fontcolor=slategray];
       rp -> uwsgi [label="http:// (tcp) or unix:// (socket)"];
-      uwsgi -> searxng1 -> redis;
-      uwsgi -> searxng2 -> redis;
-      uwsgi -> searxng3 -> redis;
-      uwsgi -> searxng4 -> redis;
+      uwsgi -> searxng1 -> valkey;
+      uwsgi -> searxng2 -> valkey;
+      uwsgi -> searxng3 -> valkey;
+      uwsgi -> searxng4 -> valkey;
   }
 
 }
diff --git a/docs/admin/installation-uwsgi.rst b/docs/admin/installation-uwsgi.rst
index 78da22f45..a2152409e 100644
--- a/docs/admin/installation-uwsgi.rst
+++ b/docs/admin/installation-uwsgi.rst
@@ -235,19 +235,19 @@ major release is from Dec. 2013, since the there had been only bugfix releases
   **In Tyrant mode, there is no way to get additional groups, and the uWSGI
   process misses additional permissions that may be needed.**
 
-For example on Fedora (RHEL): If you try to install a redis DB with socket
+For example on Fedora (RHEL): If you try to install a valkey DB with socket
 communication and you want to connect to it from the SearXNG uWSGI, you will see a
 *Permission denied* in the log of your instance::
 
-  ERROR:searx.redisdb: [searxng (993)] can't connect redis DB ...
-  ERROR:searx.redisdb:   Error 13 connecting to unix socket: /usr/local/searxng-redis/run/redis.sock. Permission denied.
+  ERROR:searx.valkeydb: [searxng (993)] can't connect valkey DB ...
+  ERROR:searx.valkeydb:   Error 13 connecting to unix socket: /usr/local/searxng-valkey/run/valkey.sock. Permission denied.
   ERROR:searx.plugins.limiter: init limiter DB failed!!!
 
 Even if your *searxng* user of the uWSGI process is added to additional groups
-to give access to the socket from the redis DB::
+to give access to the socket from the valkey DB::
 
   $ groups searxng
-  searxng : searxng searxng-redis
+  searxng : searxng searxng-valkey
 
 To see the effective groups of the uwsgi process, you have to look at the status
 of the process, by example::
@@ -257,7 +257,7 @@ of the process, by example::
   searxng      186      93  0 12:44 ?        00:00:01 /usr/sbin/uwsgi --ini searxng.ini
 
 Here you can see that the additional "Groups" of PID 186 are unset (missing gid
-of ``searxng-redis``)::
+of ``searxng-valkey``)::
 
   $ cat /proc/186/task/186/status
   ...
diff --git a/docs/admin/searx.limiter.rst b/docs/admin/searx.limiter.rst
index c23635571..6fac23868 100644
--- a/docs/admin/searx.limiter.rst
+++ b/docs/admin/searx.limiter.rst
@@ -6,7 +6,7 @@ Limiter
 
 .. sidebar:: info
 
-   The limiter requires a :ref:`Redis <settings redis>` database.
+   The limiter requires a :ref:`Valkey <settings valkey>` database.
 
 .. contents::
    :depth: 2
diff --git a/docs/admin/settings/index.rst b/docs/admin/settings/index.rst
index eb0e07a53..b9d0408ea 100644
--- a/docs/admin/settings/index.rst
+++ b/docs/admin/settings/index.rst
@@ -20,8 +20,7 @@ Settings
    settings_server
    settings_ui
    settings_redis
+   settings_valkey
    settings_outgoing
    settings_categories_as_tabs
    settings_plugins
-
-
diff --git a/docs/admin/settings/settings_redis.rst b/docs/admin/settings/settings_redis.rst
index 9fb067553..e1221ac32 100644
--- a/docs/admin/settings/settings_redis.rst
+++ b/docs/admin/settings/settings_redis.rst
@@ -4,46 +4,34 @@
 ``redis:``
 ==========
 
-.. _Redis.from_url(url): https://redis-py.readthedocs.io/en/stable/connections.html#redis.client.Redis.from_url
+.. _Valkey: https://valkey.io
 
-A redis DB can be connected by an URL, in :py:obj:`searx.redisdb` you
-will find a description to test your redis connection in SearXNG.  When using
-sockets, don't forget to check the access rights on the socket::
+.. attention::
 
-  ls -la /usr/local/searxng-redis/run/redis.sock
-  srwxrwx--- 1 searxng-redis searxng-redis ... /usr/local/searxng-redis/run/redis.sock
+   SearXNG is switching from the Redis DB to Valkey_. The configuration
+   description of Valkey_ in SearXNG can be found here: :ref:`settings
+   <settings valkey>`.
 
-In this example read/write access is given to the *searxng-redis* group.  To get
-access rights to redis instance (the socket), your SearXNG (or even your
-developer) account needs to be added to the *searxng-redis* group.
-
-``url`` : ``$SEARXNG_REDIS_URL``
-  URL to connect redis database, see `Redis.from_url(url)`_ & :ref:`redis db`::
-
-    redis://[[username]:[password]]@localhost:6379/0
-    rediss://[[username]:[password]]@localhost:6379/0
-    unix://[[username]:[password]]@/path/to/socket.sock?db=0
+If you have built and installed a local Redis DB for SearXNG, it is recommended
+to uninstall it now and replace it with the installation of a Valkey_ DB.
 
 .. _Redis Developer Notes:
 
 Redis Developer Notes
 =====================
 
-To set up a local redis instance, first set the socket path of the Redis DB
-in your YAML setting:
+To uninstall SearXNG's local Redis DB you can use:
 
-.. code:: yaml
+.. code:: sh
 
-   redis:
-     url: unix:///usr/local/searxng-redis/run/redis.sock?db=0
+   # stop your SearXNG instance
+   $ ./utils/searxng.sh remove.redis
 
-Then use the following commands to install the redis instance (:ref:`manage
-redis.help`):
+Remove the Redis DB in your YAML setting:
 
-.. code:: sh
+.. code:: yaml
 
-   $ ./manage redis.build
-   $ sudo -H ./manage redis.install
-   $ sudo -H ./manage redis.addgrp "${USER}"
-   # don't forget to logout & login to get member of group
+   redis:
+     url: unix:///usr/local/searxng-redis/run/redis.sock?db=0
 
+To install Valkey_ read: :ref:`Valkey Developer Notes`
diff --git a/docs/admin/settings/settings_server.rst b/docs/admin/settings/settings_server.rst
index 84908d43f..59c0d7791 100644
--- a/docs/admin/settings/settings_server.rst
+++ b/docs/admin/settings/settings_server.rst
@@ -36,7 +36,7 @@
 
 ``limiter`` :  ``$SEARXNG_LIMITER``
   Rate limit the number of request on the instance, block some bots.  The
-  :ref:`limiter` requires a :ref:`settings redis` database.
+  :ref:`limiter` requires a :ref:`settings valkey` database.
 
 .. _public_instance:
 
diff --git a/docs/admin/settings/settings_valkey.rst b/docs/admin/settings/settings_valkey.rst
new file mode 100644
index 000000000..396d5c8ad
--- /dev/null
+++ b/docs/admin/settings/settings_valkey.rst
@@ -0,0 +1,53 @@
+.. _settings valkey:
+
+===========
+``valkey:``
+===========
+
+.. _Valkey:
+    https://valkey.io
+.. _Valkey-Installation:
+    https://valkey.io/topics/installation/
+.. _There are several ways to specify a database number:
+    https://valkey-py.readthedocs.io/en/stable/connections.html#valkey.Valkey.from_url
+
+A Valkey_ DB can be connected by an URL, in section :ref:`valkey db` you will
+find a description to test your valkey connection in SearXNG.
+
+``url`` : ``$SEARXNG_VALKEY_URL``
+  URL to connect valkey database. `There are several ways to specify a database
+  number`_::
+
+    valkey://[[username]:[password]]@localhost:6379/0
+    valkeys://[[username]:[password]]@localhost:6379/0
+    unix://[[username]:[password]]@/path/to/socket.sock?db=0
+
+  When using sockets, don't forget to check the access rights on the socket::
+
+    ls -la /usr/local/searxng-valkey/run/valkey.sock
+    srwxrwx--- 1 searxng-valkey searxng-valkey ... /usr/local/searxng-valkey/run/valkey.sock
+
+  In this example read/write access is given to the *searxng-valkey* group.  To
+  get access rights to valkey instance (the socket), your SearXNG (or even your
+  developer) account needs to be added to the *searxng-valkey* group.
+
+
+.. _Valkey Developer Notes:
+
+Valkey Developer Notes
+======================
+
+To set up a local Valkey_ DB, set the URL connector in your YAML setting:
+
+.. code:: yaml
+
+   valkey:
+     url: valkey://localhost:6379/0
+
+To install a local Valkey_ DB from package manager read `Valkey-Installation`_
+or use:
+
+.. code:: sh
+
+   $ ./utils/searxng.sh install valkey
+   # restart your SearXNG instance
diff --git a/docs/admin/update-searxng.rst b/docs/admin/update-searxng.rst
index 16715f00d..d4a197603 100644
--- a/docs/admin/update-searxng.rst
+++ b/docs/admin/update-searxng.rst
@@ -56,7 +56,7 @@ SearXNG is growing rapidly, the services and opportunities are change every now
 and then, to name just a few:
 
 - Bot protection has been switched from filtron to SearXNG's :ref:`limiter
-  <limiter>`, this requires a :ref:`Redis <settings redis>` database.
+  <limiter>`, this requires a :ref:`Valkey <settings valkey>` database.
 
 - To save bandwidth :ref:`cache busting <static_use_hash>` has been implemented.
   To get in use, the ``static-expires`` needs to be set in the :ref:`uwsgi
@@ -89,5 +89,5 @@ to see if there are some left overs.  In this example there exists a *old*
    --------------
    ERROR: settings.yml in /etc/searx/ is deprecated, move file to folder /etc/searxng/
    ...
-   INFO    searx.redisdb                 : connecting to Redis db=0 path='/usr/local/searxng-redis/run/redis.sock'
-   INFO    searx.redisdb                 : connected to Redis
+   INFO    searx.valkeydb                 : connecting to Valkey db=0 path='/usr/local/searxng-valkey/run/valkey.sock'
+   INFO    searx.valkeydb                 : connected to Valkey
diff --git a/docs/conf.py b/docs/conf.py
index 468c160cb..a7221e48b 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -149,7 +149,7 @@ intersphinx_mapping = {
     "jinja": ("https://jinja.palletsprojects.com/en/stable/", None),
     "linuxdoc" : ("https://return42.github.io/linuxdoc/", None),
     "sphinx" : ("https://www.sphinx-doc.org/en/master/", None),
-    "redis": ('https://redis.readthedocs.io/en/stable/', None),
+    "valkey": ('https://valkey-py.readthedocs.io/en/stable/', None),
 }
 
 issues_github_path = "searxng/searxng"
diff --git a/docs/dev/engines/offline/nosql-engines.rst b/docs/dev/engines/offline/nosql-engines.rst
index 76f5cfb61..551600c4e 100644
--- a/docs/dev/engines/offline/nosql-engines.rst
+++ b/docs/dev/engines/offline/nosql-engines.rst
@@ -7,7 +7,7 @@ NoSQL databases
 .. sidebar:: further read
 
    - `NoSQL databases <https://en.wikipedia.org/wiki/NoSQL>`_
-   - `redis.io <https://redis.io/>`_
+   - `valkey.io <https://valkey.io/>`_
    - `MongoDB <https://www.mongodb.com>`_
 
 .. contents::
@@ -22,7 +22,7 @@ NoSQL databases
 
 The following `NoSQL databases`_ are supported:
 
-- :ref:`engine redis_server`
+- :ref:`engine valkey_server`
 - :ref:`engine mongodb`
 
 All of the engines above are just commented out in the :origin:`settings.yml
@@ -45,7 +45,7 @@ section :ref:`private engines`.
 Extra Dependencies
 ==================
 
-For using :ref:`engine redis_server` or :ref:`engine mongodb` you need to
+For using :ref:`engine valkey_server` or :ref:`engine mongodb` you need to
 install additional packages in Python's Virtual Environment of your SearXNG
 instance.  To switch into the environment (:ref:`searxng-src`) you can use
 :ref:`searxng.sh`::
@@ -61,20 +61,20 @@ Configure the engines
 their structure.
 
 
-.. _engine redis_server:
+.. _engine valkey_server:
 
-Redis Server
-------------
+Valkey Server
+-------------
 
-.. _redis: https://github.com/andymccurdy/redis-py#installation
+.. _valkey: https://github.com/andymccurdy/valkey-py#installation
 
 .. sidebar:: info
 
-   - ``pip install`` redis_
-   - redis.io_
-   - :origin:`redis_server.py <searx/engines/redis_server.py>`
+   - ``pip install`` valkey_
+   - valkey.io_
+   - :origin:`valkey_server.py <searx/engines/valkey_server.py>`
 
-.. automodule:: searx.engines.redis_server
+.. automodule:: searx.engines.valkey_server
   :members:
 
 
@@ -94,4 +94,3 @@ MongoDB
 
 .. automodule:: searx.engines.mongodb
   :members:
-
diff --git a/docs/dev/lxcdev.rst b/docs/dev/lxcdev.rst
index 9edd9f672..22c16ff0d 100644
--- a/docs/dev/lxcdev.rst
+++ b/docs/dev/lxcdev.rst
@@ -140,7 +140,7 @@ proxy :ref:`installation nginx` into the archlinux container run:
 .. sidebar:: Fully functional SearXNG suite
 
    From here on you have a fully functional SearXNG suite (including a
-   :ref:`redis db`).
+   :ref:`valkey db`).
 
 In such a SearXNG suite admins can maintain and access the debug log of the
 services quite easy.
diff --git a/docs/dev/makefile.rst b/docs/dev/makefile.rst
index a66ce2f22..4781b2ce6 100644
--- a/docs/dev/makefile.rst
+++ b/docs/dev/makefile.rst
@@ -362,17 +362,6 @@ can be used to convenient run common build tasks of the static files.
 .. program-output:: bash -c "cd ..; ./manage static.help"
 
 
-.. _manage redis.help:
-
-``./manage redis.help``
-=======================
-
-The ``./manage redis.*`` command line can be used to convenient run common Redis
-tasks (:ref:`Redis developer notes`).
-
-.. program-output:: bash -c "cd ..; ./manage redis.help"
-
-
 .. _manage go.help:
 
 ``./manage go.help``
diff --git a/docs/src/searx.redisdb.rst b/docs/src/searx.redisdb.rst
deleted file mode 100644
index 625378c91..000000000
--- a/docs/src/searx.redisdb.rst
+++ /dev/null
@@ -1,8 +0,0 @@
-.. _redis db:
-
-========
-Redis DB
-========
-
-.. automodule:: searx.redisdb
-  :members:
diff --git a/docs/src/searx.redislib.rst b/docs/src/searx.redislib.rst
deleted file mode 100644
index b4604574c..000000000
--- a/docs/src/searx.redislib.rst
+++ /dev/null
@@ -1,8 +0,0 @@
-.. _searx.redis:
-
-=============
-Redis Library
-=============
-
-.. automodule:: searx.redislib
-  :members:
diff --git a/docs/src/searx.valkeydb.rst b/docs/src/searx.valkeydb.rst
new file mode 100644
index 000000000..165b88111
--- /dev/null
+++ b/docs/src/searx.valkeydb.rst
@@ -0,0 +1,8 @@
+.. _valkey db:
+
+==========
+Valkey DB
+==========
+
+.. automodule:: searx.valkeydb
+  :members:
diff --git a/docs/src/searx.valkeylib.rst b/docs/src/searx.valkeylib.rst
new file mode 100644
index 000000000..a0f935d2a
--- /dev/null
+++ b/docs/src/searx.valkeylib.rst
@@ -0,0 +1,8 @@
+.. _searx.valkey:
+
+==============
+Valkey Library
+==============
+
+.. automodule:: searx.valkeylib
+  :members: