[fix] container: remove static hashing (#410)

* [fix] container: remove static hashing

Allows browser cache heuristics to properly work.

Related https://github.com/searxng/searxng/pull/5006
Closes https://github.com/searxng/searxng-docker/issues/409

* [fix] container: don't revalidate at every request

As Granian no longer handles static files directly, the whole process goes through Flask, which apart from being slow, is resource intensive, even to serve HTTP 304 responses.

Caddyfile

@@ -42,14 +42,14 @@ encode zstd gzip
 	path /stats/checker
 }
 
-@imageproxy {
-	path /image_proxy
-}
-
 @static {
 	path /static/*
 }
 
+@imageproxy {
+	path /image_proxy
+}
+
 header {
 	# CSP (https://content-security-policy.com)
 	Content-Security-Policy "upgrade-insecure-requests; default-src 'none'; script-src 'self'; style-src 'self' 'unsafe-inline'; form-action 'self' https:; font-src 'self'; frame-ancestors 'self'; base-uri 'self'; connect-src 'self'; img-src * data:; frame-src https:;"
@@ -77,9 +77,9 @@ header @api {
 
 route {
 	# Cache policy
-	header Cache-Control "max-age=0, public, must-revalidate"
-	header @imageproxy Cache-Control "max-age=3600, public"
-	header @static Cache-Control "max-age=31536000, public, immutable"
+	header Cache-Control "no-cache"
+	header @static Cache-Control "public, max-age=30, stale-while-revalidate=60"
+	header @imageproxy Cache-Control "public, max-age=3600"
 }
 
 # SearXNG

searxng/settings.yml

@@ -5,7 +5,5 @@ server:
   secret_key: "ultrasecretkey"  # change this!
   limiter: false  # enable this when running the instance for a public usage on the internet
   image_proxy: true
-ui:
-  static_use_hash: true
 redis:
   url: redis://redis:6379/0