nginx反代参考配置
```
location ^~/sdko {
index index.html index.htm index.php;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
client_max_body_size 50m;
proxy_set_header X-Forwarded-Proto $scheme;
proxy_set_header X-Forwarded-Scheme $scheme;
proxy_redirect off;
proxy_connect_timeout 240;
proxy_send_timeout 240;
proxy_read_timeout 240;
if ($request_method = 'OPTIONS') {
#复杂接口浏览器会发 options请求，优化Options请求反馈时间
more_set_headers 'Access-Control-Allow-Origin *';
more_set_headers 'Access-Control-Allow-Methods GET,POST,PUT,DELETE,PATCH,OPTIONS';
return 200;
}
#跨域处理
more_set_headers 'Access-Control-Allow-Origin: *';
more_set_headers 'Access-Control-Allow-Credentials: true';
more_set_headers 'Access-Control-Allow-Headers: *,';
more_set_headers 'Access-Control-Allow-Methods: GET,POST,PUT,DELETE,OPTIONS';
#暴露部分请求头，可实现文件分片加载，提高渲染速度
more_set_headers 'Access-Control-Expose-Headers: Accept-Ranges, Content-Range, Set-Cookie, Content-Length';
#部署好签服务的服务器，需换成对应的IP地址
proxy_pass http://ip:28080/sdko;
}
```