override nginx 404 as static page with redirect target

static-html/nginx-template.conf

@@ -5,13 +5,19 @@ server {
     #charset utf-8;
     #access_log  /var/log/nginx/host.access.log  main;
 
+    # error page handler:
+    error_page 404 = @pass404redirect;
+
+    # redirect to top-level 404:
+    location @pass404redirect {
+      return 302 ${NGINX_404_REDIR_TARGET} ;
+    }
+
     location / {
         root   /usr/share/nginx/html;
         index  index.html index.htm;
     }
 
-    error_page  404              /404.html;
-
     # redirect server error pages to the static page /50x.html
     #
     error_page   500 502 503 504  /50x.html;