use expires directive and cleanup

nginx/nginx.conf

@@ -1,26 +1,14 @@
 server {
-
   listen 80;
+  root /usr/share/nginx/html;
+  error_page 500 502 503 504 /50x.html;
 
-  # Location block for index.html with a 6-hour cache
   location = /index.html {
-    root /usr/share/nginx/html;
-    add_header Cache-Control "public, max-age=21600, must-revalidate"; 
-    try_files $uri $uri/ /index.html;
+    expires 6h;
   }
 
-  # Location block for all other files with a 7-day cache
   location / {
-    root /usr/share/nginx/html;
-    index index.html index.htm;
+    expires 7d;
     try_files $uri $uri/ /index.html;
-    add_header Cache-Control "public, max-age=604800, must-revalidate";
-  }
-
-
-  error_page 500 502 503 504 /50x.html;
-
-  location = /50x.html {
-      root /usr/share/nginx/html;
   }
-}
+}