Received subscribe acknowledgement with invalid QoS values from the broker

服务端：emqx

客户端：php-mqtt/client 3.x

PHP≥7.4

​

• 需求

  • 项目需要自定义订阅客户端的离线和上线

• 代码

  $server   = 'emqx server url';
  $port     = 1883;
  $clientId = 'sys_client';
  $username = 'test';
  $password = '12345678';
  $topics='$SYS/brokers/+/clients/#';//订阅客户端上线下线
  $mqtt = new \PhpMqtt\Client\MqttClient($server, $port, $clientId);
  $connectionSettings = (new \PhpMqtt\Client\ConnectionSettings)
      ->setUsername($username)
      ->setPassword($password);
  
  $mqtt->connect($connectionSettings, true);
  $mqtt->subscribe($topics, function ($topic, $message) {
  			echo sprintf("Received message on topic [%s]: %s\n", $topic, $message);
  		}, 0);
  $mqtt->loop(true);
  $mqtt->disconnect();
  

• 为什么会出现异常？

  Received subscribe acknowledgement with invalid QoS values from the broker.
  

• 如何解决？

  • 参考EMQX的ACL文档做规则设置：https://www.emqx.io/docs/zh/v4.3/advanced/acl-file.html

  • 默认的acl.conf

    {allow, {user, "dashboard"}, subscribe, ["$SYS/#"]}.
     
    {allow, {ipaddr, "127.0.0.1"}, pubsub, ["$SYS/#", "#"]}.
     
    {deny, all, subscribe, ["$SYS/#", {eq, "#"}]}.
     
    {allow, all}.
    

  • 修改acl.conf，为了安全起见，我这里做了只允许指定的ip订阅$SYS/brokers/+/clients/#

    {allow, {user, "dashboard"}, subscribe, ["$SYS/#"]}.
     
    {allow, {ipaddr, "127.0.0.1"}, pubsub, ["$SYS/#", "#"]}.
    
    #指定ip订阅
    {allow, {ipaddr, "127.0.0.1"}, subscribe, ["$SYS/brokers/+/clients/#"]}.
    #允许所有客户端订阅
    #{allow, all, subscribe, ["$SYS/brokers/+/clients/#"]}.
    
    {deny, all, subscribe, ["$SYS/#", {eq, "#"}]}.
     
    {allow, all}.
    

  • 然后，通过命令行的方式运行一下，应该就不会报错了