Web 服务器已关闭

Question

我正在为我的项目使用 docker。我想将我的项目从其他地方移动到数字海洋，所以我创建了一个 Droplet 并将项目文件从旧服务器复制到新服务器。但是，当时该项目在新服​​务器上运行不佳。抛出 错误 521 Web 服务器已关闭。另外，我使用 Cloudflare 进行 DNS 设置。 注意：该项目在旧服务器上运行良好，80 端口正在侦听。但是，在新服务器上，80 端口未在侦听。我不知道为什么。

nginx.conf :

    worker_processes 4;

events {
  worker_connections 4096;
}

http {

  server {
    listen 80 default_server;
    server_name "";
    return 444;
  }

  server {
    server_name game-dev.myappapp.com;

    location / {
      proxy_set_header X-Real-IP $remote_addr;
      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
      proxy_set_header Host $http_host;
      proxy_set_header X-NginX-Proxy true;
      proxy_http_version 1.1;
      proxy_set_header Upgrade $http_upgrade;
      proxy_set_header Connection "upgrade";

      proxy_pass http://game_nodes;
      proxy_redirect off;
    }
  }
  server {
    if ($host = game-dev.myappapp.com) {
      return 301 https://$host$request_uri;
    }


    listen 80;
    listen [::]:80;
    server_name game-dev.myappapp.com;
    return 404;
  }

  upstream game_nodes {
    # enable sticky session
    #ip_hash;
    server game-alpha:3000;
    keepalive 8;
  }

  server {
    server_name api-dev.myappapp.com;

    location / {
      proxy_set_header X-Real-IP $remote_addr;
      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
      proxy_set_header Host $http_host;
      proxy_set_header X-NginX-Proxy true;

      proxy_pass http://main_nodes;
      proxy_redirect off;

    }
  }

  server {
    if ($host = api-dev.myappapp.com) {
      return 301 https://$host$request_uri;
    }

    listen 80;
    listen [::]:80;
    server_name api-dev.myappapp.com;
    return 404;
  }

  upstream main_nodes {
    server main-alpha:8000;
    server main-beta:8000;
    keepalive 8;
  }
}