update grafana.vcl

grafana/files/varnish-grafana.vcl.j2

@@ -3,18 +3,38 @@ import vsthrottle;
 
 backend default {
 {%- if frontend == 'traefik' %}
-    .host = "grafana";
+	.host = "grafana";
 {%- elif frontend == 'nginx' %}
-    .host = "127.0.0.1";
+	.host = "127.0.0.1";
 {%- endif %}
-    .port = "3000";
+	.port = "3000";
 }
 
 sub vcl_recv {
 	# Happens before we check if we have this in cache already.
 
+	# Removing Google Analytics added parameters
+	if(req.url ~ "(\?|&)(_t|utm_[a-z]+|mr:[A-z]+|gclid|cx|ie|cof|siteurl)=") {
+		set req.url = regsuball(req.url, "(_t|utm_[a-z]+|mr:[A-z]+|gclid|cx|ie|cof|siteurl)=[%.+-_A-z0-9]+&?", "");
+	}
+	set req.url = regsub(req.url, "\?&", "?");
+	set req.url = regsub(req.url, "(\?|&)+$", "");
+
 	if (req.method != "GET" && req.method != "HEAD") {
-	    return (pass);
+			return (pass);
+	}
+	# grace period (stale content delivery while revalidating)
+	set req.http.grace = "none";
+	# Accept-Encoding header clean-up
+	if (req.http.Accept-Encoding) {
+		# use gzip when possible, otherwise use deflate
+		if (req.http.Accept-Encoding ~ "gzip") {
+			set req.http.Accept-Encoding = "gzip";
+		} elsif (req.http.Accept-Encoding ~ "deflate") {
+			set req.http.Accept-Encoding = "deflate";
+		} else {
+			unset req.http.Accept-Encoding;
+		}
 	}
 
 	# Goodbye incoming cookies:
@@ -24,10 +44,6 @@ sub vcl_recv {
 	unset req.http.user-agent;
 	unset req.http.referer;
 
-	if(req.url ~ "(\?|&)(_t|utm_[a-z]+|mr:[A-z]+)=") {
-		set req.url = regsuball(req.url, "(_t|utm_[a-z]+|mr:[A-z]+)=[%.+-_A-z0-9]+&?", "");
-	}
-	set req.url = regsub(req.url, "(\?|&)+$", "");
 	return (hash);
 }
 
@@ -36,6 +52,35 @@ sub vcl_hash {
 	return(lookup);
 }
 
+sub vcl_backend_fetch {
+	/*
+	 * we force keep-alive to the upstream
+	 */
+	set bereq.http.Connection = "Keep-Alive";
+	unset bereq.http.X-Varnish;
+}
+
+sub vcl_hit {
+	if (obj.ttl >= 0s) {
+		# normal hit
+		return (deliver);
+	}
+	# Looking at stale content
+	if (std.healthy(req.backend_hint)) {
+		# Backend is healthy. Limit age to 10s.
+		if (obj.ttl + 10s > 0s) {
+			set req.http.grace = "normal(limited)";
+			return (deliver);
+		} else {
+			# backend is sick - use full grace
+			if (obj.ttl + obj.grace > 0s) {
+				set req.http.grace = "full";
+				return (deliver);
+			}
+		}
+	}
+}
+
 sub vcl_miss {
 	if (req.url ~ "^/render/") {
 		if (vsthrottle.is_denied(req.http.X-Real-IP, 10, 30s, 10s)) {
@@ -70,4 +115,22 @@ sub vcl_deliver {
 	# 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;
+	set resp.http.Server = "nginx";
+
+	set resp.http.grace = req.http.grace;
+	# could be useful to know if the object was in cache or not
+	if (obj.hits > 0) {
+		set resp.http.X-Cache = "HIT";
+	} else {
+		set resp.http.X-Cache = "MISS";
+	}
+	return (deliver);
+
 }