s3utils-download.go

func DownloadFile(configuration configs.Configuration, objectKey string) string {
	downloader := createS3Downloader(configuration)

	// create a image file on /tmp directory
	file, err := os.Create(configuration.LocalImageDirectory + "/" + filepath.Base(objectKey))

	if err != nil {
		exitErrorf("DownloadFile:::Unable to open file, %v", err)
	}

	defer file.Close()

	// download from s3 bucket
	numBytes, err := downloader.Download(file,
		&s3.GetObjectInput{
			Bucket: aws.String(configuration.Bucket),
			Key:    aws.String(objectKey),
		})

	if err != nil {
		exitErrorf("Unable to download item %q, %v", objectKey, err)
	}

	fmt.Println("Downloaded", file.Name(), numBytes, "bytes")

	return configuration.LocalImageDirectory + "/" + filepath.Base(objectKey)
}