node.js – 如何使用AWS IoT向/從Web瀏覽器傳送/接收訊息

這是一個使用JS中的認知標識池來連線,釋出和對訂閱做出反應的示例.

// Configure Cognito identity pool
AWS.config.region = 'us-east-1';
var credentials = new AWS.CognitoIdentityCredentials({
IdentityPoolId: 'us-east-1:your identity pool guid',
});

// Getting AWS creds from Cognito is async, so we need to drive the rest of the mqtt client initialization in a callback
credentials.get(function(err) {
if(err) {
console.log(err);
return;
}
var requestUrl = SigV4Utils.getSignedUrl('wss', 'data.iot.us-east-1.amazonaws.com', '/mqtt',
'iotdevicegateway', 'us-east-1',
credentials.accessKeyId, credentials.secretAccessKey, credentials.sessionToken);
initClient(requestUrl);
});

function init() {
// do setup stuff
}

// Connect the client, subscribe to the drawing topic, and publish a "hey I connected" message
function initClient(requestUrl) {
var clientId = String(Math.random()).replace('.', '');
var client = new Paho.MQTT.Client(requestUrl, clientId);
var connectOptions = {
onSuccess: function () {
console.log('connected');

// subscribe to the drawing
client.subscribe("your/mqtt/topic");

// publish a lifecycle event
message = new Paho.MQTT.Message('{"id":"' + credentials.identityId + '"}');
message.destinationName = 'your/mqtt/topic';
console.log(message);
client.send(message);
},
useSSL: true,
timeout: 3,
mqttVersion: 4,
onFailure: function () {
console.error('connect failed');
}
};
client.connect(connectOptions);

client.onMessageArrived = function (message) {

try {
console.log("msg arrived: " +message.payloadString);
} catch (e) {
console.log("error! " + e);
}

};
}

請記住,授權您的IAM角色也可以訂閱/釋出.以下是一個示例：

{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"iot:Connect"
],
"Resource": "*"
},
{
"Effect": "Allow",
"Action": "iot:Receive",
"Resource": "*"
},
{
"Effect": "Allow",
"Action": "iot:Subscribe",
"Resource": [
"arn:aws:iot:us-east-1::your/mqtt/topic"
]
},
{
"Effect": "Allow",
"Action": "iot:Publish",
"Resource": [
"arn:aws:iot:us-east-1::your/mqtt/topic"
]
}
]
}