k3s/rabbitmq-chart/mqtt-tests/mqtt.go

package main

import (
	"fmt"
	"os"
	"time"

	mqtt "github.com/eclipse/paho.mqtt.golang"
)

const (
	//broker   = "tcp://rabbitmq.irdi.eu:1883" // change to your broker's IP/hostname
	broker   = "tcp://localhost:2222" // change to your broker's IP/hostname
	topic    = "test/topic"
	clientID = "go-mqtt-client"
)

func main() {
	// Message handler for received messages
	messagePubHandler := func(client mqtt.Client, msg mqtt.Message) {
		fmt.Printf("Received message: %s from topic: %s\n", msg.Payload(), msg.Topic())
	}

	// MQTT connection options
	opts := mqtt.NewClientOptions()
	opts.AddBroker(broker)
	opts.SetClientID(clientID)
	opts.OnConnect = func(c mqtt.Client) {
		fmt.Println("Connected to broker")
	}
	opts.OnConnectionLost = func(c mqtt.Client, err error) {
		fmt.Printf("Connection lost: %v\n", err)
	}
	opts.SetDefaultPublishHandler(messagePubHandler)

	fmt.Println("Connecting to broker ...")

	// Connect to the broker
	client := mqtt.NewClient(opts)
	if token := client.Connect(); token.Wait() && token.Error() != nil {
		fmt.Printf("Error connecting to broker: %v\n", token.Error())
		os.Exit(1)
	}

	// Subscribe to a topic
	if token := client.Subscribe(topic, 1, nil); token.Wait() && token.Error() != nil {
		fmt.Printf("Subscribe error: %v\n", token.Error())
		os.Exit(1)
	}

	// Publish a message
	text := "Hello from Go!"
	token := client.Publish(topic, 0, false, text)
	token.Wait()

	// Wait to receive message
	time.Sleep(5 * time.Second)

	// Disconnect
	client.Disconnect(250)
	fmt.Println("Disconnected")
}

// go run mqtt.go