From a6cfab93fa7c1b1f0a04c073df42b50f2834d845 Mon Sep 17 00:00:00 2001
From: Markus Heiser <markus.heiser@darmarit.de>
Date: Mon, 3 Jan 2022 17:43:20 +0100
Subject: [enh] add redis connector searx/shared/redisdb.py

Add a redis connector, the default DB connector is a socket at::

    unix:///usr/local/searxng-redis/run/redis.sock?db=0

To set up a redis instance simply use::

    $ ./manage redis.build
    $ sudo -H ./manage redis.install

A hint for developers:

To get access rights to this instance, your developer account needs to be added
to the *searxng-redis* group::

    $ sudo -H ./manage redis.addgrp "${USER}"
    # don't forget to logout & login to get member of group

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>
---
 searx/settings.yml         |  4 ++++
 searx/settings_defaults.py |  3 +++
 searx/shared/redisdb.py    | 41 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 48 insertions(+)
 create mode 100644 searx/shared/redisdb.py

(limited to 'searx')

diff --git a/searx/settings.yml b/searx/settings.yml
index 3227a5a55..0105c7939 100644
--- a/searx/settings.yml
+++ b/searx/settings.yml
@@ -61,6 +61,10 @@ server:
     X-Robots-Tag: noindex, nofollow
     Referrer-Policy: no-referrer
 
+redis:
+  # https://redis-py.readthedocs.io/en/stable/connections.html#redis.client.Redis.from_url
+  url: unix:///usr/local/searxng-redis/run/redis.sock?db=0
+
 ui:
   # Custom static path - leave it blank if you didn't change
   static_path: ""
diff --git a/searx/settings_defaults.py b/searx/settings_defaults.py
index 9c4711bfc..669f2fa87 100644
--- a/searx/settings_defaults.py
+++ b/searx/settings_defaults.py
@@ -169,6 +169,9 @@ SCHEMA = {
         'method': SettingsValue(('POST', 'GET'), 'POST'),
         'default_http_headers': SettingsValue(dict, {}),
     },
+    'redis': {
+        'url': SettingsValue(str, 'unix:///usr/local/searxng-redis/run/redis.sock?db=0'),
+    },
     'ui': {
         'static_path': SettingsDirectoryValue(str, os.path.join(searx_dir, 'static')),
         'templates_path': SettingsDirectoryValue(str, os.path.join(searx_dir, 'templates')),
diff --git a/searx/shared/redisdb.py b/searx/shared/redisdb.py
new file mode 100644
index 000000000..613b82a38
--- /dev/null
+++ b/searx/shared/redisdb.py
@@ -0,0 +1,41 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
+# lint: pylint
+"""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.shared import redisdb
+  >>> redisdb.init()
+  True
+  >>> db = redisdb.client()
+  >>> db.set("foo", "bar")
+  True
+  >>> db.get("foo")
+  b'bar'
+  >>>
+
+"""
+
+import logging
+import redis
+from searx import get_setting
+
+logger = logging.getLogger('searx.shared.redis')
+
+
+def client():
+    return redis.Redis.from_url(get_setting('redis.url'))
+
+
+def init():
+    try:
+        c = client()
+        logger.info("connected redis DB --> %s", c.acl_whoami())
+        return True
+    except redis.exceptions.ConnectionError as exc:
+        logger.error("can't connet redis DB ...")
+        logger.error("  %s", exc)
+    return False
-- 
cgit v1.2.3


From dca83944b588be3ec9e49486daea6cf15ef58f78 Mon Sep 17 00:00:00 2001
From: Markus Heiser <markus.heiser@darmarit.de>
Date: Fri, 7 Jan 2022 17:29:32 +0100
Subject: [fix] redis: don't create a new connection at each client() call

Suggested-by: @dalf https://github.com/searxng/searxng/pull/686#pullrequestreview-844942973
Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>
---
 searx/shared/redisdb.py | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

(limited to 'searx')

diff --git a/searx/shared/redisdb.py b/searx/shared/redisdb.py
index 613b82a38..da71d169c 100644
--- a/searx/shared/redisdb.py
+++ b/searx/shared/redisdb.py
@@ -24,10 +24,16 @@ import redis
 from searx import get_setting
 
 logger = logging.getLogger('searx.shared.redis')
+_client = None
 
 
 def client():
-    return redis.Redis.from_url(get_setting('redis.url'))
+    global _client  # pylint: disable=global-statement
+    if _client is None:
+        # not thread safe: in the worst case scenario, two or more clients are
+        # initialized only one is kept, the others are garbage collected.
+        _client = redis.Redis.from_url(get_setting('redis.url'))
+    return _client
 
 
 def init():
-- 
cgit v1.2.3