Method GetImageFile

client/oci_images.go:131–308

GetImageFile downloads an image from the server, returning an ImageFileResponse struct.

(fingerprint string, req ImageFileRequest)

// GetImageFile downloads an image from the server, returning an ImageFileResponse struct.
func (r *ProtocolOCI) GetImageFile(fingerprint string, req ImageFileRequest) (*ImageFileResponse, error) {
	ctx := context.Background()

	// Get the cached entry.
	info, ok := r.cache[fingerprint]
	if !ok {
		_, err := exec.LookPath("skopeo")
		if err != nil {
			return nil, errors.New("OCI container handling requires \"skopeo\" be present on the system")
		}

		err, ok := r.errors[fingerprint]
		if ok {
			return nil, err
		}

		return nil, errors.New("Image not found")
	}

	// Quick checks.
	if req.MetaFile == nil && req.RootfsFile == nil {
		return nil, errors.New("No file requested")
	}

	if os.Geteuid() != 0 {
		return nil, errors.New("OCI image export currently requires root access")
	}

	// Get some temporary storage.
	ociPath, err := os.MkdirTemp(r.tempPath, "incus-oci-")
	if err != nil {
		return nil, err
	}

	defer logger.WarnOnError(func() error { return os.RemoveAll(ociPath) }, "Failed to remove temporary directory")

	err = os.Mkdir(filepath.Join(ociPath, "oci"), 0o700)
	if err != nil {
		return nil, err
	}

	err = os.Mkdir(filepath.Join(ociPath, "image"), 0o700)
	if err != nil {
		return nil, err
	}

	// Copy the image.
	if req.ProgressHandler != nil {
		req.ProgressHandler(ioprogress.ProgressData{Text: "Retrieving OCI image from registry"})
	}

	imageTag := "latest"

	stdout, err := r.runSkopeo(
		"copy", info.Alias,
		"--remove-signatures",
		fmt.Sprintf("oci:%s:%s", filepath.Join(ociPath, "oci"), imageTag),
	)