Publish to MQTT topic in AWS IoT from Ionic 5 - amazon-web-services

Question

I am using ionic 5 for a mobile app that runs on iOS and Android. How can I publish a message to an MQTT topic in AWS IoT from Ionic 5? I have generated certificates for the client authentication in AWS IoT already. Are there any libraries available for this?

Answer 1

You can use a variety of MQTT client libraries in the Ionic 5 app to send messages to an MQTT subject in Amazon IoT. Paho MQTT JavaScript Client Library is one such library.
The steps below can be used to incorporate this library into the Ionic 5 app:
With npm, add the Paho MQTT JavaScript client library to your Ionic application.
npm install paho-mqtt
Import the library into your Ionic application, then build a new MQTT
client object.
import { Client } from 'paho-mqtt';
const client = new Client('wss://your-aws-iot-endpoint', 'your-client-id');
Use the client object and your generated certificates to establish a
connection to the Amazon IoT MQTT broker.
Using the send method of the client object, you can send messages to
an MQTT topic after the client has established a connection.
Use certificate-based authentication in place of username and
password by using the following code:
const options = {
useSSL: true,
userName: 'your-aws-iot-username',
password: 'your-aws-iot-password',
ssl: {
key: 'path/to/your/device-private-key.pem',
cert: 'path/to/your/device-certificate.pem',
ca: 'path/to/your/ca-certificate.pem',
},
onSuccess: () => console.log('MQTT client connected'),
onFailure: (error) => console.error('MQTT client connection failed:', error),
};
Using the send method of the client object as before, you can publish
messages to an MQTT topic after the client has established a
connection.
const topic = 'your-mqtt-topic';
const message = new Message('your-message-payload');
message.destinationName = topic;
client.send(message);