我试图用 mosquitto 设置一个新服务器。当我在 Ubuntu 18.04 上设置 mosquitto 时，FireFox 和 Chrome 都可以通过 websocket 连接到它。当我在 Ubuntu 20.04 上设置 mosquitto 时，只有 Chrome 可以通过 websocket 连接到它。FireFox 开发人员工具给出了错误

The connection to wss://domain.example.com:10002/mqtt was interrupted while the page was loading.
Object { invocationContext: undefined, errorCode: 7, errorMessage: "AMQJS0007E Socket error:undefined." }

问题：如何让 Ubuntu 20.04 上的 mosquitto 与 Ubuntu 18.04 的行为相同，或者让 FireFox 连接到 Ubuntu 20.04 上的 mosquitto？

重现错误的步骤

这是我用来在全新安装的 Ubuntu 18.04 或 Ubuntu 20.04 上安装 mosquitto 的脚本。我确保保持相同的服务器和 IP 地址，因此 VPS 实例不会在每次实验之间发生变化：

#!bin/bash

# The following sensitive information has been substituted: somewebsitethatIown.com, example.com, username, password, ports 10001, 10002, 10009

apt-get update -y;

mkdir -p /etc/ssl/star.example.com/
cd /etc/ssl/star.example.com/
wget https://somewebsitethatIown.com/ssls.tar
tar xvf ssls.tar

cd ~/

# MQTT

apt-get install -y build-essential python quilt python-setuptools python3 libssl-dev cmake libc-ares-dev uuid-dev daemon libwebsockets-dev;

# user required for mqtt process
adduser --system --shell /bin/bash --group --disabled-password --home /home/mosquitto mosquitto;

mkdir -p ~/mqtt
cd ~/mqtt
wget http://mosquitto.org/files/source/mosquitto-1.4.10.tar.gz
tar zxvf mosquitto-1.4.10.tar.gz
cd mosquitto-1.4.10/
sed -i "s|WITH_WEBSOCKETS:=no|WITH_WEBSOCKETS:=yes|g" config.mk
make
make install
cp mosquitto.conf /etc/mosquitto
ldconfig


touch /etc/mosquitto/passwd
mosquitto_passwd -b /etc/mosquitto/passwd username password

mv /etc/mosquitto/mosquitto.conf /etc/mosquitto/mosquitto.conf.back


cat <<EOT >> /etc/mosquitto/mosquitto.conf
port 10009 localhost
listener 10001
certfile /etc/ssl/example.com/star.example.com.full.crt
cafile /etc/ssl/example.com/star.example.com.ca-bundle
keyfile /etc/ssl/example.com/STAR_example_com_key.txt
listener 10002
protocol websockets
certfile /etc/ssl/example.com/star.example.com.full.crt
cafile /etc/ssl/example.com/star.example.com.ca-bundle
keyfile /etc/ssl/example.com/STAR_example_com_key.txt
allow_anonymous false
password_file /etc/mosquitto/passwd
EOT

cat <<EOT >> /etc/systemd/system/mosquitto.service
[Unit]
Description=Mosquitto
[Service]
Type=simple
ExecStart=/usr/local/sbin/mosquitto -c /etc/mosquitto/mosquitto.conf
[Install]
WantedBy=multi-user.target
EOT

systemctl enable mosquitto.service;
systemctl start mosquitto.service;

启动并运行后，我会转到另一台计算机/服务器并创建一个简单的反应项目，如下所示：

npx create-react-app mosq;
cd mosq;
npm install --save paho-mqtt;
rm src/App.js;
cat <<EOT >> src/App.js
import React from "react";
import { render } from "react-dom";
import Paho from "paho-mqtt";

const host = "domain.example.com;
const user = "username";
const pass = "password";

const topicWeb = "topic-web";
const port = 10002;

export default class App extends React.Component {

  componentDidMount() {

      try {
          const clientId = "id"+Math.random();
          const client = new Paho.Client(host, port, clientId);
          client.onConnectionLost = (response) => {
              console.log(
                  "MQTT Lost Connection: " +
            (response.errorCode !== 0
                ? response.errorMessage + " code: " + response.errorCode
                : "Unknown MQTT Error")
              );
          };
        client.connect({
            onSuccess:()=>{
                console.log("MQTT Connected....");
                client.subscribe(topicWeb)
            },
            onFailure:e=>console.log("MQTT Error:", e),
            timeout:2,
            useSSL:true,
            userName:user,
            password:pass
        });
      } catch (e) {
          console.log(e);
      }
  }

  render() {
    return <h1>hello world</h1>;
  }
}

EOT
npm start;

然后我使用FireFox或Chrome访问http://localhost:3000（或用服务器托管页面的IP地址替换localhost）。MQTT Connected...无论我是在 Ubuntu 18.04 还是 20.04 上运行我的 mosquitto bash 脚本，Chrome 的开发人员工具都会显示。FireFox 将显示MQTT Connected...我是否在 Ubuntu 18.04 上运行了 mosquitto bash 脚本，但The connection to wss://domain.example.com:10002/mqtt was interrupted while the page was loading.如果我在 Ubuntu 20.04 上运行了 mosquitto bash 脚本，则会显示错误消息。