Nginx解决跨域问题（前端服务器，接口服务器）记录

使用可视化工具宝塔，没有可忽略

遇到的问题：前端服务器访问接口服务器跨域

例：前端服务器访问地址 11.11.11.11:9008

后端服务器访问地址 22.22.22.22:9009

通常是前端代码中访问接口http://22.22.22.22:9009/ceshi提示跨域

Access to XMLHttpRequest at ‘http://22.22.22.22:9009/ceshi’ from origin ‘http://11.11.11.11:9008’ has been blocked by CORS policy: Response to preflight request doesn’t pass access control check: No ‘Access-Control-Allow-Origin’ header is present on the requested resource.

解决方式：

首先前端代码中访问自身地址，http://11.11.11.11:9008，不要去访问http://22.22.22.22:9009/ceshi
然后使用Nginx反向代理转发到http://22.22.22.22:9009

修改11.11.11.11服务器上的Nginx配置指向接口地址
```
proxy_pass http://22.22.22.22:9009;
```

listen 9008;
server_name www.xxx.com;
index index.php index.html index.htm default.php default.htm default.html;
root /www/wwwroot/www.xxx.com/xxx;

...
...
location /
    {
       proxy_pass http://22.22.22.22:9009;
       proxy_connect_timeout 60s;
       proxy_send_timeout 60s;
       proxy_read_timeout 60s;
       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 http;

       proxy_http_version 1.1;
       proxy_set_header Upgrade $http_upgrade;
       proxy_set_header Connection "upgrade";
       proxy_set_header Host $http_host;
    }