# Nginx反向代理跨域option问题解决

- URL: https://wuming.si/blog/1299/
- Author: Aaron
- Published: 2018-03-26
- Language: en
- Categories: Technology
- Originally published at: https://blog.wo.ai/archives/1299

# CORS on Nginx

The following Nginx configuration enables CORS, with support for preflight requests.
    
    
    #
    # Wide-open CORS config for nginx
    #
    location / {
         if ($request_method = 'OPTIONS') {
            add_header 'Access-Control-Allow-Origin' '*';
            add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';
            #
            # Custom headers and headers various browsers *should* be OK with but aren't
            #
            add_header 'Access-Control-Allow-Headers' 'DNT,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Range';
            #
            # Tell client that this pre-flight info is valid for 20 days
            #
            add_header 'Access-Control-Max-Age' 1728000;
            add_header 'Content-Type' 'text/plain; charset=utf-8';
            add_header 'Content-Length' 0;
            return 204;
         }
         if ($request_method = 'POST') {
            add_header 'Access-Control-Allow-Origin' '*';
            add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';
            add_header 'Access-Control-Allow-Headers' 'DNT,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Range';
            add_header 'Access-Control-Expose-Headers' 'Content-Length,Content-Range';
         }
         if ($request_method = 'GET') {
            add_header 'Access-Control-Allow-Origin' '*';
            add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';
            add_header 'Access-Control-Allow-Headers' 'DNT,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Range';
            add_header 'Access-Control-Expose-Headers' 'Content-Length,Content-Range';
         }
    }
    
    

First is tricking Nginx that a 405 status is actually a 200 OK and then proxy_pass it to your HAProxy like this:
    
    
    error_page 405 =200 @405;
    location @405 {
        root /;
        proxy_pass http://yourproxy:8080;
    }
    

The second solution is just to catch the OPTIONS request and build a response for those requests:
    
    
    location / {
        if ($request_method = OPTIONS ) {
            add_header Content-Length 0;
            add_header Content-Type text/plain;
            return 200;
        }
    }