Question

我一直在尝试使用Eclipse Paho MQTT客户端的javacscript版本来访问Google IOTCore MQTT Bridge，如下所示：

https://cloud.google.com/iot/docs/how-tos/mqtt-bridge

但是，无论我做什么，任何尝试连接已知良好凭据（与其他客户端一起工作）都会导致此连接错误：

errorCode: 7, errorMessage: "AMQJS0007E Socket error:undefined."

没什么可去的，所以我想知道是否有人通过Javascript与Eclipse Paho成功连接到MQTT Bridge，这是Google在他们的文档中建议的客户端实现。

我已经完成了他们的故障排除步骤，事情似乎在起作用，所以也没有任何帮助。

https://cloud.google.com/iot/docs/troubleshooting

我注意到在他们的文档中他们有Java / Python等的示例代码，但不是Javascript，所以我想知道它是否根本不受支持而且他们的文档没有提到这样。

我已将我的代码简化为仅使用“Hello World＆＃39; Paho文档中的示例，据我所知，我已经正确完成了事情（包括使用我的设备路径作为ClientID，将JWT令牌作为密码，指定一个未使用的＆＃39; userName字段并明确要求MQTT v3.1.1）。

与此同时，我通过他们的HTTP桥接回到轮询，但这有明显的延迟和网络流量缺点。

// Create a client instance
client = new Paho.MQTT.Client("mqtt.googleapis.com", Number(8883), "projects/[my-project-id]/locations/us-central1/registries/[my registry name]/devices/[my device id]");

// set callback handlers
client.onConnectionLost = onConnectionLost;
client.onMessageArrived = onMessageArrived;

// connect the client
client.connect({
    mqttVersion: 4,   // maps to MQTT V3.1.1, required by IOTCore
    onSuccess:onConnect,
    onFailure: onFailure,
    userName: 'unused',  // suggested by Google for this field
    password: '[My Confirmed Working JWT Token]' // working JWT token

function onFailure(resp) {
    console.log(resp);
}


// called when the client connects
function onConnect() {
  // Once a connection has been made, make a subscription and send a message.
  console.log("onConnect");
  client.subscribe("World");
  message = new Paho.MQTT.Message("Hello");
  message.destinationName = "World";
  client.send(message);
}

// called when the client loses its connection
function onConnectionLost(responseObject) {
  if (responseObject.errorCode !== 0) {
    console.log("onConnectionLost:"+responseObject.errorMessage);
  }
}

// called when a message arrives
function onMessageArrived(message) {
  console.log("onMessageArrived:"+message.payloadString);
}

Answer 1

I'm a Googler (but I don't work in Cloud IoT).

Your code looks good to me and it should work. I will try it for myself this evening or tomorrow and report back to you.

I've spent the past day working on a Golang version of the samples published on Google's documentation. Like you, I was disappointed to not see all Google's regular languages covered by samples.

Are you running the code from a browser or is it running on Node.JS?

Do you have a package.json (if Node) that you would share too please?

Update

Here's a Node.JS (JavaScript but non-browser) that connects to Cloud IoT, subscribes to /devices/${DEVICE}/config and publishes to /devices/${DEVICE}/events.

https://gist.github.com/DazWilkin/65ad8890d5f58eae9612632d594af2de

Place all the files in the same directory
Replace values in index.js of the location of Google's CA and your key
Replaces [[YOUR-X]] values in config.json
Use "npm install" to pull the packages
Use node index.js

You should be able to pull messages from the Pub/Sub subscription and you should be able to send config messages to the device.

是否可以通过Javascript连接到Google IOTCore MQTT Bridge？

1 个答案: