nginx的一次跨域处理

1、事故

访问图片资源的时候，发生了跨域，具体报错如下所示：

403 Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'null' is therefore not allowed access. The response had HTTP status code 403

显然是跨域导致的。

2、解决方法

在nginx的server段的location添加如下内容：

location /pag {
          if ($request_method = 'OPTIONS') {
             add_header Access-Control-Allow-Origin *;
             add_header Access-Control-Allow-Methods GET,POST,PUT,DELETE,OPTIONS;
             add_header Access-Control-Allow-Headers Origin,x-requested-with,Content-Type,Accept,X-Cookie,secret-key,identity-id;
             return 204;
          }
          proxy_redirect off;
          proxy_pass_header Server;
          proxy_set_header Host $http_host;
          proxy_set_header X-Real-IP $remote_addr;
          proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
          proxy_set_header X-Forwarded-Proto $scheme;
          proxy_pass http://10.10.8.9:9090/pag;
      }

修改完毕后，nginx  -s reload使配置生效。

注：add_header Access-Control-Allow-Origin *;只能添加一行，多了会报错。根据报错信息排查，如果配置中Access-Control-Allow-Headers没有的，就加进去。