add_header 'Access-Control-Allow-Origin' *; 
#允许带上cookie请求 
add_header 'Access-Control-Allow-Credentials' 'true'; 
#允许请求的方法，比如 GET/POST/PUT/DELETE 
add_header 'Access-Control-Allow-Methods' *; 
#允许请求的header 
add_header 'Access-Control-Allow-Headers' *;