Merge pull request #24 from niiknow/bionic

update issue #19 and #21

Author: noogen

files/etc/nginx/sites-enabled/server.conf

@@ -27,11 +27,13 @@ server {
     server_name                      _;
     root                             /usr/share/nginx/html;
     index                            index.html index.htm;
-    error_page                       403 = @403;
-    error_page                       404 = @404;
-    error_page                       415 = @415;
-    error_page                       500 = @500;
-    error_page                       502 503 504 = @empty;
+
+# error should simply return as error so user can use image onerror handler
+#    error_page                       403 = @403;
+#    error_page                       404 = @404;
+#    error_page                       415 = @415;
+#    error_page                       500 = @500;
+#    error_page                       502 503 504 = @empty;
     error_page                       301 302 307 = @handle_redirect;
 
 # begin image_filter stuff
@@ -63,6 +65,8 @@ server {
     proxy_cache                      remoteimages;
     proxy_ssl_server_name            on;
     proxy_intercept_errors           on;
+    proxy_cache_use_stale            updating error timeout http_500 http_502 http_503 http_504;
+    proxy_cache_background_update    on;
 
 # valid for "any" http status within 10 minutes
     proxy_cache_valid                any 10m;