test_mqtt.go

package main

import (
	"fmt"
	"os"
	"os/signal"
	"syscall"

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

var messagePubHandler mqtt.MessageHandler = func(client mqtt.Client, msg mqtt.Message) {
	fmt.Printf("Received message: %s from topic: %s\n", msg.Payload(), msg.Topic())
}

var connectHandler mqtt.OnConnectHandler = func(client mqtt.Client) {
	fmt.Println("Connected")
}

var connectLostHandler mqtt.ConnectionLostHandler = func(client mqtt.Client, err error) {
	fmt.Printf("Connect lost: %v", err)
}

func main() {

	opts := mqtt.NewClientOptions()

	opts.AddBroker("mqtt://dev.rightech.io:1883")

	opts.SetClientID("")
	opts.SetUsername("")
	opts.SetPassword("")

	opts.SetDefaultPublishHandler(messagePubHandler)

	opts.OnConnect = connectHandler
	opts.OnConnectionLost = connectLostHandler

	client := mqtt.NewClient(opts)

	if token := client.Connect(); token.Wait() && token.Error() != nil {
		panic(token.Error())
	}

	exit := make(chan os.Signal, 1)
	signal.Notify(exit, syscall.SIGINT, syscall.SIGTERM)
	<-exit
}