main.go

package main

import (
	"fmt"
	mqtt "github.com/eclipse/paho.mqtt.golang"
	"time"
)

var massagePubHandler mqtt.MessageHandler = func(client mqtt.Client, msg mqtt.Message) {
	fmt.Printf("Сообщение получено: %s , из топика: %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("Connection lost error - %v\n", err.Error())
}

func main() {
	var broker = "mqtt0.bast-dev.ru"
	var port = 1883
	var topicPrefix = "service/weather_logger/#"
	var userName = "hackathon"
	var password = "Autumn2021"
	opts := mqtt.NewClientOptions()
	opts.AddBroker(fmt.Sprintf("tcp://%s:%d/", broker, port))
	opts.SetClientID(fmt.Sprintf("data-set%d", time.Now().Unix()))
	opts.SetUsername(userName)
	opts.SetPassword(password)
	opts.SetDefaultPublishHandler(massagePubHandler)
	opts.OnConnect = connectHandler
	opts.OnConnectionLost = connectLostHandler
	client := mqtt.NewClient(opts)

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

	sub(client, topicPrefix)
	publish(client, topicPrefix)
	client.Disconnect(100)

}
func publish(client mqtt.Client, topic string) {
	num := 16
	for true{
		text := fmt.Sprintf("Message %d", num)
		token := client.Publish(topic, 0, false, text)
		token.Wait()
		time.Sleep(time.Second * 1)
	}
}

func sub(client mqtt.Client, topic string) {
	token := client.Subscribe(topic, 1, nil)
	token.Wait()
	fmt.Printf("Subscribed to topic: %s\n", topic)
}