解决Nginx报错 unknown “upgrade” variable

前言

前两天更新宝塔面板后，刚好网站的SSL证书也到期了，在更新保村新的ssl证书时候，nginx报错导致我无法保存

#报错内容
nginx: [emerg] unknown "upgrade" variable
nginx: configuration file /www/server/nginx/conf/nginx.conf test failed
#报错内容
nginx: [emerg] unknown "upgrade" variable
nginx: configuration file /www/server/nginx/conf/nginx.conf test failed
#报错内容
nginx: [emerg] unknown "upgrade" variable
nginx: configuration file /www/server/nginx/conf/nginx.conf test failed

在网上找到解决 报错 connection_upgrade 未知变量 的办法，原理应该是一样的，应该是宝塔反向代理的问题？

解决方法

在nginx配置的http模块中加入如下配置

映射 upgrade 变量为 http_upgrade 变量

    map $http_upgrade $connection_upgrade {
        default upgrade;
        ''      close;
    }
    map $http_upgrade $connection_upgrade {
        default upgrade;
        ''      close;
    }
    map $http_upgrade $connection_upgrade {
        default upgrade;
        ''      close;
    }