NGINX - 配置WebSocket代理

HTTP Upgrade机制可以用来将HTTP连接升级到WebSocket连接，需要用到Upgrade和Connection头。对于代理服务器，需要将来自客户端的Upgrade请求带到后端服务器上，同时保持长连接。

location /ws/ {
    proxy_pass http://wsbackend;
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "Upgrade";
}