func()

in plugin/source/s3/s3.go [67:128]

• 47 lines of code
• 10 McCabe index (conditional complexity)

func (s *Source) DownloadToPath(dlPath string) error {

	if err := os.MkdirAll(dlPath, 0755); err != nil {
		return err
	}
	s.logger.Debugf(0, "copy directory %s is ready", dlPath)

	/*
		AWS download:
		- build credentials and init session
		- create temporary file in dlPath
		- download s3 data to temp file
		- rename temporary file to output file
		- if archive: decompress to dlPath
	*/
	cfg := aws.NewConfig().WithRegion(s.Region)
	if s.Credentials.AccessKeyID != "" && s.Credentials.SecretAccessKey != "" {
		cfg = cfg.WithCredentials(
			credentials.NewStaticCredentials(s.Credentials.AccessKeyID, s.Credentials.SecretAccessKey, ""),
		)
	}
	sess, err := session.NewSession(cfg)
	if err != nil {
		s.logger.Debugf(0, "failed to create AWS session: %s", err)
		return err
	}
	dl := s3manager.NewDownloader(sess)

	outfn := filepath.Join(dlPath, filepath.Base(s.Key))
	// create tmpfile in dlPath to store S3 contents before Renaming to final location
	tmpfh, err := ioutil.TempFile(dlPath, "")
	if err != nil {
		s.logger.Debugf(0, "failed to create output file for S3 download: %s", err)
		return err
	}
	defer tmpfh.Close()
	n, err := dl.Download(tmpfh, &s3.GetObjectInput{
		Bucket: &s.Bucket,
		Key:    &s.Key,
	})
	if err != nil {
		s.logger.Debugf(0, "failed to download data from S3: %s", err)
		return err
	}
	s.logger.Debugf(0, "downloaded %d bytes for %s:%s from S3", n, s.Bucket, s.Key)
	tmpfh.Close()

	if err := os.Rename(tmpfh.Name(), outfn); err != nil {
		s.logger.Errorf("failed to relocate", outfn, dlPath)
		return err
	}

	s.logger.Debugf(0, "relocated downloaded file from %s to %s", tmpfh.Name(), outfn)
	if s.Archive {
		if err := archiver.Unarchive(outfn, dlPath); err != nil {
			s.logger.Errorf("failed to unarchive %s to dir %s", outfn, dlPath)
			return err
		}
	}

	return nil
}