反向代理502 Bad Gateway nginx

一般出现这个问题原因是你的代理地址是非https的，而被代理的地址是https的，解决方案

完整的反向代理代码：

#PROXY-START/

location ^~ /
{
   #被代理的地址
    proxy_pass http://your-backend-server;  
    proxy_set_header Host abacus.zhucn.org;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header REMOTE-HOST $remote_addr;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection $connection_upgrade;
    proxy_http_version 1.1;
    #强制指定SSL协议，就不会出现502了
    proxy_ssl_server_name on;
    proxy_ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
    # proxy_hide_header Upgrade;

    add_header X-Cache $upstream_cache_status;
    #Set Nginx Cache

    set $static_fileB1qufNZH 0;
    if ( $uri ~* "\.(gif|png|jpg|css|js|woff|woff2)$" )
    {
        set $static_fileB1qufNZH 1;
        expires 1m;
    }
    if ( $static_fileB1qufNZH = 0 )
    {
        add_header Cache-Control no-cache;
    }
}
#PROXY-END/