add new parameter called server.public_instance

for enabling by default advanced limiter functions
in the future allow us to add features just for the public instances

searx/plugins/limiter.py

@@ -3,6 +3,7 @@
 # pyright: basic
 """see :ref:`limiter src`"""
 
+import sys
 import flask
 
 from searx import redisdb
@@ -23,10 +24,15 @@ def pre_request():
 
 
 def init(app: flask.Flask, settings) -> bool:
-    if not settings['server']['limiter']:
+    if not settings['server']['limiter'] and not settings['server']['public_instance']:
         return False
     if not redisdb.client():
-        logger.error("The limiter requires Redis")
+        logger.error(
+            "The limiter requires Redis, please consult the documentation: "
+            + "https://docs.searxng.org/admin/searx.botdetection.html#limiter"
+        )
+        if settings['server']['public_instance']:
+            sys.exit(1)
         return False
     app.before_request(pre_request)
     return True