Merge pull request #719 from herzog31/extend-surrogate-keys

Extend surrogate keys instead of replacing them

Author: harmony7

Diff for: etc/vcl_snippets/fetch.vcl

@@ -106,16 +106,30 @@
     if (beresp.ttl > 0s && (req.request == "GET" || req.request == "HEAD") && !req.http.x-pass ) {
         unset beresp.http.set-cookie;
 
-        # init surrogate keys
-        if (beresp.http.X-Magento-Tags) {
-            set beresp.http.Surrogate-Key = beresp.http.X-Magento-Tags " text";
-        } else {
-            set beresp.http.Surrogate-Key = "text";
-        }
+        # init surrogate keys if on outermost node
+        if (fastly.ff.visits_this_service == 0 && req.restarts == 0) {
+            if (beresp.http.X-Magento-Tags) {
+                if (beresp.http.Surrogate-Key) {
+                    set beresp.http.Surrogate-Key = beresp.http.Surrogate-Key " " beresp.http.X-Magento-Tags " text";
+                } else {
+                    set beresp.http.Surrogate-Key = beresp.http.X-Magento-Tags " text";
+                }
+            } else {
+                if (beresp.http.Surrogate-Key) {
+                    set beresp.http.Surrogate-Key = beresp.http.Surrogate-Key " text";
+                } else {
+                    set beresp.http.Surrogate-Key = "text";
+                }
+            }
 
-        # set surrogate keys by content type if they are image/script or CSS
-        if (beresp.http.Content-Type ~ "(image|script|css)") {
-            set beresp.http.Surrogate-Key = re.group.1;
+            # set surrogate keys by content type if they are image/script or CSS
+            if (beresp.http.Content-Type ~ "(image|script|css)") {
+                if (beresp.http.Surrogate-Key) {
+                    set beresp.http.Surrogate-Key = beresp.http.Surrogate-Key " " re.group.1;
+                } else {
+                    set beresp.http.Surrogate-Key = re.group.1;
+                }
+            }
         }
     }