func writeImageLayer()

in container/go/pkg/compat/write.go [74:109]

• 35 lines of code
• 8 McCabe index (conditional complexity)

func writeImageLayer(l v1.Layer, idx int, outDir string) error {
	d, err := l.Digest()
	if err != nil {
		return errors.Wrapf(err, "unable to get digest from layer %d", idx)
	}
	outDigestFile := path.Join(outDir, fmt.Sprintf("%03d.sha256", idx))
	if err := ioutil.WriteFile(outDigestFile, []byte(d.Hex), os.ModePerm); err != nil {
		return errors.Wrapf(err, "unable to write the digest of layer %d to %s", idx, outDigestFile)
	}
	m, err := l.MediaType()
	if err != nil {
		return errors.Wrap(err, "unable to get the media type of layer")
	}
	var contents io.ReadCloser
	var outLayerFile string
	if isCompressed(m) {
		contents, err = l.Compressed()
		outLayerFile = path.Join(outDir, fmt.Sprintf("%03d.tar.gz", idx))
	} else {
		contents, err = l.Uncompressed()
		outLayerFile = path.Join(outDir, fmt.Sprintf("%03d.tar", idx))

	}
	if err != nil {
		return errors.Wrapf(err, "unable to get the contents of layer %d", idx)
	}
	defer contents.Close()
	o, err := os.Create(outLayerFile)
	if err != nil {
		return errors.Wrapf(err, "unable to create %s to write layer %d", outLayerFile, idx)
	}
	if _, err := io.Copy(o, contents); err != nil {
		return errors.Wrapf(err, "unable to write the contents of layer %d to %s", idx, outLayerFile)
	}
	return nil
}