Golang: Send image over MQTT

send_image_mqtt.go

package main

import (
  "fmt"
  "io/ioutil"
  "os"

  log "github.com/Sirupsen/logrus"
  MQTT "github.com/eclipse/paho.mqtt.golang"
)


var (
  mqttBroker   = "tcp://HOST:1883"
  mqttClientId = "Send_image_mqtt"
  mqttTopic    = "test/topic"
  imageFile    = "test.png"
)

func main() {

  opts := MQTT.NewClientOptions()
  opts.AddBroker(mqttBroker)
  opts.SetClientID(mqttClientId)

  c := MQTT.NewClient(opts)
  if token := c.Connect(); token.Wait() && token.Error() != nil {
    log.Warn("Error connecting to broker: ", mqttBroker)
    panic(token.Error())
  }

  fileHandle, err := os.Open(imageFile)
  if err != nil {
    log.Fatal("Error opening file.")
  }

  defer func () {
    if err := fileHandle.Close(); err != nil {
      panic(err)
    }
  }()

  contents, err := ioutil.ReadAll(fileHandle)
  if err != nil {
    log.Fatal("Error reading file.")
  }

  fmt.Println(len(contents))
  token := c.Publish(mqttTopic, 0, false, string(contents))
  token.Wait()
  log.Info(token.Error())

}