WebSocket 握手期间出现错误 200：Aws 负载均衡器 + ec2 websocket

Question

我在 aws ec2 实例前使用负载均衡器（将来我会有更多）。在这个 ec2 中，我有一个由 nginx 在端口 80 上提供服务的网站，一个在 8080 上监听的 nodejs 应用程序和在 4555 上的 websocket。

我的 nginx.conf 有根据位置传递请求的规则/如您所见：

server {
        listen       80 default_server;
        listen       [::]:80 default_server;
        server_name  localhost;
        root         /var/www/html;

        # Load configuration files for the default server block.
        include /etc/nginx/default.d/*.conf;

       #try_files $uri $uri/ @rewrite;
       # location @rewrite {
       #    rewrite ^/(.*)$ /index.php?param=$1;
       #}

    location /api {
               proxy_pass http://127.0.0.1:8080;
               proxy_http_version 1.1;
               proxy_set_header Upgrade $http_upgrade;
               proxy_set_header Connection 'upgrade';
               proxy_set_header Host $host;
               proxy_cache_bypass $http_upgrade;
        }

    location /chat {
                proxy_pass http://127.0.0.1:4555;
                proxy_http_version 1.1;
                proxy_set_header Upgrade $http_upgrade;
                proxy_set_header Connection 'upgrade';
                proxy_set_header Host $host;
                proxy_cache_bypass $http_upgrade;
        }
}

当我将连接直接重定向到实例时它可以工作，但是现在我们在前面有了负载均衡器，它就不再工作了。

Web 应用程序输出：

WebSocket 与 'wss://www.domain.com/socket.io/?EIO=3&transport=websocket' 连接失败：WebSocket 握手期间出错：意外响应代码：200

这是标题：

Request URL: wss://www.domain.com/socket.io/?EIO=3&transport=websocket
Request Method: GET
Status Code: 200 OK
Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Connection: keep-alive
Content-Type: text/html; charset=UTF-8
Date: Mon, 20 May 2019 18:53:37 GMT
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Pragma: no-cache
Server: nginx/1.14.1
Transfer-Encoding: chunked
X-Powered-By: PHP/5.6.40
Accept-Encoding: gzip, deflate, br
Accept-Language: pt-BR,pt;q=0.9,en-US;q=0.8,en;q=0.7
Cache-Control: no-cache
Connection: Upgrade
Cookie: PHPSESSID=a6v5ebp25cajb1dj9s6je605a3
Host: www.domain.com
Origin: https://www. domain.com
Pragma: no-cache
Sec-WebSocket-Extensions: permessage-deflate; client_max_window_bits
Sec-WebSocket-Key: kmYaufsBu3UFD+qGm1vlGA==
Sec-WebSocket-Version: 13
Upgrade: websocket
User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.157 Safari/537.36
EIO: 3
transport: websocket