net::ERR_CONNECTION_REFUSED . How to correctly configure Nginx with Socket.io?

[MarcoI]

With this /etc/nginx/conf.d/default.conf :  

    server {
        listen 443 ssl http2 default_server;
        server_name ggc.world;

        ssl_certificate /etc/ssl/certs/chained.pem;
        ssl_certificate_key /etc/ssl/private/domain.key;
        ssl_session_timeout 5m;
        ssl_protocols TLSv1 TLSv1.1 TLSv1.2 TLSv1.3;
        ssl_ciphers
EECDH+CHACHA20:EECDH+CHACHA20-draft:EECDH+AES128:RSA+AES128:EECDH+AES256:RSA+AES256:EECDH+3DES:RSA+3DES:!MD5;
        ssl_prefer_server_ciphers on;
        ssl_session_cache shared:SSL:50m;
        ssl_dhparam /etc/ssl/certs/dhparam.pem;
        #ssl_stapling on;
        #ssl_stapling_verify on;

        access_log /var/log/nginx/ggcworld-access.log combined;

        add_header Strict-Transport-Security "max-age=31536000";
        location = /favicon.ico { access_log off; log_not_found off; }
        location / {
            proxy_pass http://127.0.0.1:8080;
            proxy_http_version 1.1;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection "upgrade";
        }
    }

    server {
        listen 80 default_server;
        listen [::]:80 default_server;
        error_page 497 https://$host:$server_port$request_uri;
        server_name www.ggc.world;
        return 301 https://$server_name$request_uri;

        access_log /var/log/nginx/ggcworld-access.log combined;

        add_header Strict-Transport-Security "max-age=31536000";
        location = /favicon.ico { access_log off; log_not_found off; }
        location / {
            proxy_pass http://127.0.0.1:8080;
            proxy_http_version 1.1;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection "upgrade";
        }
    }

    # https://www.nginx.com/blog/nginx-nodejs-websockets-socketio/
    # https://gist.github.com/uorat/10b15a32f3ffa3f240662b9b0fefe706
    # http://nginx.org/en/docs/stream/ngx_stream_core_module.html

    upstream websocket {
        ip_hash;
        server localhost:3000;
    }

    server {
        listen       81;
        server_name  ggc.world www.ggc.world;

        #location / {
        location ~ ^/(websocket|websocket\/socket-io) {
            proxy_pass http://127.0.0.1:4201;
            proxy_http_version 1.1;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection "upgrade";
            proxy_set_header X-Forwared-For $remote_addr;
            proxy_set_header Host $host;

            proxy_redirect off;
            proxy_set_header X-Real-IP $remote_addr;
         }

    }
    #
https://stackoverflow.com/questions/40516288/webpack-dev-server-with-nginx-proxy-pass
 

with vue.config.js :   

    module.exports = {
      // options...
      publicPath: '',
      devServer: {
        host: 'localhost',
      }
    }

and with this webpack.config.js :   

    {
        "mode": "development",
        "entry": [
            "src/index.js",
            "webpack-dev-server/client?http://" + require("os").hostname() +
":3000/" 
        ],
        "output": {
            "path": __dirname+'/static',
            "filename": "[name].[chunkhash:8].js"
        },
        "module": {
            "rules": [
                {
                    "test": /\.vue$/,
                    "exclude": /node_modules/,
                    "use": "vue-loader"
                },
                {
                    "test": /\.pem$/,
                    "use": "file-loader"
                }
            ]
        },
        plugins: [
            new BrowserSyncPlugin(
                {
                    host: 'localhost',
                    port: 3000,
                    proxy: 'http://localhost:8080'
                },
                {
                    reload: false
                }
            ),
        ],
        node: {
            __dirname: false,
            __filename: false
        },
        resolve: {
            extension: ['*', '.pem']
        },
        devServer: {
            watchOptions: {
                aggregateTimeout: 300,
                poll: 1000
            }
        }
    }

And still get this error message:

GET https://localhost/sockjs-node/info?t=1580397983088
net::ERR_CONNECTION_REFUSED     :  

https://drive.google.com/open?id=1Dm-PC85pjGfqIeMOS45k3hvV9PANgOH5

Posted at Nginx Forum: https://forum.nginx.org/read.php?2,286850,286866#msg-286866