WEBSOCKETS NGINX - 握手期间出现错误 502

Question

[error] 11709#11709: *53 upstream prematurely closed connection while reading response header from upstream,

这是我得到的错误。

server {
    server_name ....;

    location = /favicon.ico { access_log off; log_not_found off; }
    location /static/ {
        root /home/......;
    }

     location / {
        include proxy_params;
        proxy_pass http://unix:/run/gunicorn.sock;
    }

    location /ws/ {
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_redirect off;
        proxy_pass http://127.0.0.1:8001;
    }

}

我正在使用来自 chrome 的以下客户端应用程序：

var exampleSocket = new WebSocket("wss://....../ws/.....")
exampleSocket.onopen = function (event) {
  console.log("Here's some text that the server is urgently awaiting!");
};

可能的错误是什么，我无法调试它。我想使用 websocket 和 django-channels 发送通知，但每次我请求服务器时，它都会给我 502 错误。