Function generateCommitImageConfig

pkg/imgutil/commit/commit.go:237–297

generateCommitImageConfig returns commit oci image config based on the container's image.

(ctx context.Context, container containerd.Container, img containerd.Image, diffID digest.Digest, opts *Opts)

// generateCommitImageConfig returns commit oci image config based on the container's image.
func generateCommitImageConfig(ctx context.Context, container containerd.Container, img containerd.Image, diffID digest.Digest, opts *Opts) (ocispec.Image, error) {
	spec, err := container.Spec(ctx)
	if err != nil {
		return ocispec.Image{}, err
	}

	baseConfig, _, err := imgutil.ReadImageConfig(ctx, img) // aware of img.platform
	if err != nil {
		return ocispec.Image{}, err
	}

	// TODO(fuweid): support updating the USER/ENV/... fields?
	if opts.Changes.CMD != nil {
		baseConfig.Config.Cmd = opts.Changes.CMD
	}
	if opts.Changes.Entrypoint != nil {
		baseConfig.Config.Entrypoint = opts.Changes.Entrypoint
	}
	if opts.Author == "" {
		opts.Author = baseConfig.Author
	}

	createdBy := ""
	if spec.Process != nil {
		createdBy = strings.Join(spec.Process.Args, " ")
	}

	createdTime := time.Now()
	arch := baseConfig.Architecture
	if arch == "" {
		arch = runtime.GOARCH
		log.G(ctx).Warnf("assuming arch=%q", arch)
	}
	os := baseConfig.OS
	if os == "" {
		os = runtime.GOOS
		log.G(ctx).Warnf("assuming os=%q", os)
	}
	log.G(ctx).Debugf("generateCommitImageConfig(): arch=%q, os=%q", arch, os)
	return ocispec.Image{
		Platform: ocispec.Platform{
			Architecture: arch,
			OS:           os,
		},

		Created: &createdTime,
		Author:  opts.Author,
		Config:  baseConfig.Config,
		RootFS: ocispec.RootFS{
			Type:    "layers",
			DiffIDs: append(baseConfig.RootFS.DiffIDs, diffID),
		},
		History: append(baseConfig.History, ocispec.History{
			Created:    &createdTime,
			CreatedBy:  createdBy,
			Author:     opts.Author,
			Comment:    opts.Message,
			EmptyLayer: (diffID == emptyGZLayer),