Merge pull request #686 from return42/lib_redis

Add redis DB and connector

Makefile

@@ -63,6 +63,7 @@ test.shell:
 		utils/lib_nvm.sh \
 		utils/lib_static.sh \
 		utils/lib_go.sh \
+		utils/lib_redis.sh \
 		utils/filtron.sh \
 		utils/searx.sh \
 		utils/morty.sh \

docs/admin/engines/settings.rst

@@ -142,6 +142,36 @@ Global Settings
 ``default_http_headers``:
   Set additional HTTP headers, see `#755 <https://github.com/searx/searx/issues/715>`__
 
+
+.. _settings redis:
+
+``redis:``
+----------
+
+.. _Redis.from_url(url): https://redis-py.readthedocs.io/en/stable/connections.html#redis.client.Redis.from_url
+
+``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
+
+.. admonition:: Tip for developers
+
+   To set up a redis instance simply use::
+
+     $ ./manage redis.build
+     $ sudo -H ./manage redis.install
+
+   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
+
+.. _settings outgoing:
+
 ``outgoing:``
 -------------
 

docs/src/searx.shared.redisdb.rst

@@ -0,0 +1,8 @@
+.. _redis db:
+
+========
+Redis DB
+========
+
+.. automodule:: searx.shared.redisdb
+  :members:

manage

@@ -17,6 +17,9 @@ source "$(dirname "${BASH_SOURCE[0]}")/utils/lib_static.sh"
 # shellcheck source=utils/lib_go.sh
 source "$(dirname "${BASH_SOURCE[0]}")/utils/lib_go.sh"
 
+# shellcheck source=utils/lib_redis.sh
+source "$(dirname "${BASH_SOURCE[0]}")/utils/lib_redis.sh"
+
 # config
 
 PYOBJECTS="searx"
@@ -74,9 +77,10 @@ docker.:
 gecko.driver:
   download & install geckodriver if not already installed (required for
   robot_tests)
-EOF
-    nvm.help
-    cat <<EOF
+redis:
+  build     : build redis binaries at $(redis._get_dist)
+  install   : create user (${REDIS_USER}) and install systemd service (${REDIS_SERVICE_NAME})
+  help      : show more redis commands
 node.:
   env       : download & install npm dependencies locally
   clean     : drop locally npm installations

requirements.txt

@@ -13,3 +13,4 @@ uvloop==0.16.0
 httpx-socks[asyncio]==0.7.2
 langdetect==1.0.9
 setproctitle==1.2.2
+redis==4.1.0

searx/settings.yml

@@ -62,6 +62,10 @@ 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: ""

searx/settings_defaults.py

@@ -170,6 +170,9 @@ def apply_schema(settings, schema, path_list):
         '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')),

searx/shared/redisdb.py

@@ -0,0 +1,47 @@
+# 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')
+_client = None
+
+
+def client():
+    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():
+    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