Look for manifests in the local cache next to the full images.

pkg/cache/cache.go

@@ -145,20 +145,53 @@ func LocalSource(opts *config.KanikoOptions, cacheKey string) (v1.Image, error)
 type cachedImage struct {
 	digest string
 	v1.Image
+	mfst *v1.Manifest
 }
 
 func (c *cachedImage) Digest() (v1.Hash, error) {
 	return v1.NewHash(c.digest)
 }
 
+func (c *cachedImage) Manifest() (*v1.Manifest, error) {
+	if c.mfst == nil {
+		return c.Image.Manifest()
+	}
+	return c.mfst, nil
+}
+
+func mfstFromPath(p string) (*v1.Manifest, error) {
+	f, err := os.Open(p)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+	return v1.ParseManifest(f)
+}
+
 func cachedImageFromPath(p string) (v1.Image, error) {
 	imgTar, err := tarball.ImageFromPath(p, nil)
 	if err != nil {
 		return nil, errors.Wrap(err, "getting image from path")
 	}
 
+	// Manifests may be present next to the tar, named with a ".json" suffix
+	mfstPath := p + ".json"
+
+	var mfst *v1.Manifest
+	if _, err := os.Stat(mfstPath); err != nil {
+		logrus.Debugf("Manifest does not exist at file: %s", mfstPath)
+	} else {
+		mfst, err = mfstFromPath(mfstPath)
+		if err != nil {
+			logrus.Debugf("Error parsing manifest from file: %s", mfstPath)
+		} else {
+			logrus.Infof("Found manifest at %s", mfstPath)
+		}
+	}
+
 	return &cachedImage{
 		digest: filepath.Base(p),
 		Image:  imgTar,
+		mfst:   mfst,
 	}, nil
 }

pkg/executor/build.go

@@ -213,6 +213,8 @@ func (s *stageBuilder) build() error {
 			return err
 		}
 		timing.DefaultRun.Stop(t)
+	} else {
+		logrus.Info("Skipping unpacking as no commands require it.")
 	}
 	if err := util.DetectFilesystemWhitelist(constants.WhitelistPath); err != nil {
 		return err

pkg/util/image_util.go

@@ -72,7 +72,7 @@ func RetrieveSourceImage(stage config.KanikoStage, opts *config.KanikoOptions) (
 
 	// Finally, check if local caching is enabled
 	// If so, look in the local cache before trying the remote registry
-	if opts.Cache && opts.CacheDir != "" {
+	if opts.CacheDir != "" {
 		cachedImage, err := cachedImage(opts, currentBaseName)
 		if cachedImage != nil {
 			return cachedImage, nil