Ubuntu 默认进入3000端口：

在/etc/nginx/si.../default 里面加入

location / {

                proxy_pass http://127.0.0.1:3000;

                client_max_body_size 50m;

                proxy_set_header Upgrade $http_upgrade;

                proxy_set_header Connection "upgrade";

                proxy_http_version 1.1;

                proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

                proxy_set_header Host $host;

        }