Nginx cache rules

nginx.conf

@@ -16,6 +16,7 @@ server {
     rewrite ^/app/(.*) /app.html last;
   }
   location ~ ^/(auth|api)/ {
+    add_header Cache-Control private;
     proxy_pass http://empact;
   }
 
@@ -24,7 +25,9 @@ server {
   }
   location ~ .*\.(js|css|png)$ {
     add_header Cache-Control public;
-    expires max;
+    add_header Last-Modified $sent_http_Expires;
+    expires 1h;
+    etag on;
     gzip_static on;
     gzip on;
     gzip_proxied any;