grafana/varnish: update config

grafana/files/varnish-grafana.vcl.j2

@@ -103,29 +103,36 @@ sub vcl_backend_response {
 	# and other mistakes your backend does.
 	unset beresp.http.Set-Cookie;
 	unset beresp.http.Cookie;
-	unset beresp.http.pragma;
-	unset beresp.http.cache-control;
+	unset beresp.http.Pragma;
+	unset beresp.http.Cache-Control;
+	unset beresp.http.Expires;
 	unset beresp.http.Vary;
-	# set beresp.ttl = 120s;
-	set beresp.ttl = 600s;
+	unset beresp.http.Last-Modified;
+	unset beresp.http.ETag;
+
 	unset beresp.http.expires;
-	set beresp.http.cache-control = "max-age=120";
+	set beresp.ttl = 10s;
+	if(beresp.status == 200) {
+		set beresp.ttl = 600s;
+	}
+
 }
 
 sub vcl_deliver {
-	# Happens when we have all the pieces we need, and are about to send the
-	# response to the client.
-	#
-	# You can do accounting or modifying the final object here.
 	/*
 	 * generic synthetic handler
 	 */
-	set resp.http.Date = now;
-	unset resp.http.via;
-	unset resp.http.x-varnish;
 	unset resp.http.Server;
+	unset resp.http.X-Varnish;
+	unset resp.http.Date;
+	unset resp.http.Via;
+	unset resp.http.Age;
+	set resp.http.Vary = "Accept-Encoding";
 	set resp.http.Server = "nginx";
+	set resp.http.Date = now;
 
+	set resp.http.Cache-Control = "max-age=120";
+	set resp.http.Expires = "" + (now + (std.duration("120s", 120s)));
 	set resp.http.grace = req.http.grace;
 	# could be useful to know if the object was in cache or not
 	if (obj.hits > 0) {