tarball/tarball_src.go
func (is *tarballImageSource) GetManifest(ctx context.Context, instanceDigest *digest.Digest) ([]byte, string, error) {
	if instanceDigest != nil {
		return nil, "", fmt.Errorf("manifest lists are not supported by the %q transport", transportName)
	}
	return is.manifest, imgspecv1.MediaTypeImageManifest, nil
}
func (is *tarballImageSource) GetManifest(ctx context.Context, instanceDigest *digest.Digest) ([]byte, string, error) {
	if instanceDigest != nil {
		return nil, "", fmt.Errorf("manifest lists are not supported by the %q transport", transportName)
	}
	return is.manifest, imgspecv1.MediaTypeImageManifest, nil
}
func ( is * tarballImageSource ) GetManifest ( ctx context . Context , instanceDigest * digest . Digest ) ( [ ] byte , string , error ) { if instanceDigest != nil { return nil , " " , fmt . Errorf ( " " , transportName ) } return is . manifest , imgspecv1 . MediaTypeImageManifest , nil }
// GetManifest returns the image's manifest along with its MIME type (which may be empty when it can't be determined but the manifest is available).
// It may use a remote (= slow) service.
// If instanceDigest is not nil, it contains a digest of the specific manifest instance to retrieve (when the primary manifest is a manifest list);
// this never happens if the primary manifest is not a manifest list (e.g. if the source never returns manifest lists).
GetManifest returns the image s manifest along with its MIME type ( which may be empty when it can t be determined but the manifest is available ) . It may use a remote ( = slow ) service . If instanceDigest is not nil it contains a digest of the specific manifest instance to retrieve ( when the primary manifest is a manifest list ) ; this never happens if the primary manifest is not a manifest list ( e . g . if the source never returns manifest lists ) .