gopkgs/mqtt/init.go

package mqtt

import (
	"errors"
	gmqtt "github.com/eclipse/paho.mqtt.golang"
)

var MqttCli *gmqtt.Client

func Setup(addr, username, password string) error {
	opts := gmqtt.NewClientOptions().AddBroker(addr)
	opts.SetUsername(username)
	opts.SetPassword(password)
	c := gmqtt.NewClient(opts)
	if token := c.Connect(); token.Wait() && token.Error() != nil {
		return token.Error()
	}
	MqttCli = &c
	return nil
}

func Publish(c *gmqtt.Client, topic string, content []byte) error {
	if c == nil {
		return errors.New("client is nil")
	}
	client := *c
	token := client.Publish(topic, 1, false, content)
	token.Wait()
	return token.Error()
}

func Subscribe(c *gmqtt.Client, topic string, callback gmqtt.MessageHandler) error {
	if c == nil {
		return errors.New("client is nil")
	}
	client := *c
	token := client.Subscribe(topic, 1, callback)
	token.Wait()
	return token.Error()
}