WebSocket failed: Error during WebSocket handshake: Unexpected response code: 400
nginx 添加如下三行配置
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "upgrade";
*** 代理哪个端口就配在哪个端口***
参考：https://blog.****.net/cai454692590/article/details/94463636