map $sent_http_content_type $is_client_cacheable {
  default                             0;
  ~image/                             1;
  ~audio/                             1;
  ~video/                             1;
  text/css                            1;
  application/javascript              1;
  application/x-javascript            1;
  application/pdf                     1;
  application/font-sfnt               1;
  font/ttf                            1;
  font/opentype                       1;
  font/woff2                          1;
  application/font-woff               1;
  application/vnd.ms-fontobject       1;
  application/vnd.ms-opentype         1;
}

map $request_uri $is_proxy_cacheable {
  default                             0;
  ~*\.(png|jpe?g|bmp|gif|webp)$       1;
  ~*\.(js|css|txt)$                   1;
  ~*\.(pdf)$                          1;
  ~*\.(ttf|ott|woff2)$                1;
  ~*\.(mp3|mp4|avi|mpe?g|mov|flv)$    1;
}