searxng/docs/admin/settings/settings_redis.rst

redis:

A redis DB can be connected by an URL, in :pysearx.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:

ls -la /usr/local/searxng-redis/run/redis.sock
srwxrwx--- 1 searxng-redis searxng-redis ... /usr/local/searxng-redis/run/redis.sock

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) & redis db:

redis://[[username]:[password]]@localhost:6379/0
rediss://[[username]:[password]]@localhost:6379/0
unix://[[username]:[password]]@/path/to/socket.sock?db=0

Redis Developer Notes

To set up a local redis instance, first set the socket path of the Redis DB in your YAML setting:

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

Then use the following commands to install the redis instance (manage redis.help):

$ ./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