浏览器端ajax方式访问第三方Nginx，会提示跨域问题，可以如下设置允许跨域：

location /api/time {
add_header ‘Access-Control-Allow-Origin’ ‘’;
add_header ‘Access-Control-Allow-Headers’ '’;
add_header ‘Access-Control-Allow-Methods’ ‘GET, POST, OPTIONS, PUT, DELETE, HEAD’;
default_type text/html;
return 200 $time_iso8601;
}