Golang : Convert an image file to []byte

This is a quick tutorial on how to convert an image file to byte array. This question was originally posted to me via email at admin@socketloop.com by Mr. Aung.

Basically, Mr. Aung would like to know how to turn an image file into a byte array ( []byte )

and the answer is :

 fileToBeUploaded := "image.jpg"
 file, err := os.Open(fileToBeUploaded)

  if err != nil {
 fmt.Println(err)
 os.Exit(1)
  }

  defer file.Close()

  fileInfo, _ := file.Stat()
  var size int64 = fileInfo.Size()
  bytes := make([]byte, size)

  // read file into bytes
  buffer := bufio.NewReader(file)
  _, err = buffer.Read(bytes) // <--------------- here!

  // then we need to determine the file type
  // see https://www.socketloop.com/tutorials/golang-how-to-verify-uploaded-file-is-image-or-allowed-file-types

  filetype := http.DetectContentType(bytes)

  err = bucket.Put(path, bytes, filetype, s3.ACL("public-read"))

the code fragment is taken from https://www.socketloop.com/tutorials/golang-upload-and-download-file-to-from-aws-s3