Fix media type on unpacking layer

Signed-off-by: Lei Jitang <[email protected]>

Author: coolljt0725

image/manifest.go

@@ -89,7 +89,7 @@ func (m *manifest) validate(w walker) error {
 
 func (m *manifest) unpack(w walker, dest string) error {
 	for _, d := range m.Layers {
-		if d.MediaType != string(schema.MediaTypeImageConfig) {
+		if d.MediaType != string(schema.MediaTypeImageLayer) {
 			continue
 		}
 

image/manifest_test.go

@@ -4,6 +4,8 @@ import (
 	"archive/tar"
 	"bytes"
 	"compress/gzip"
+	"crypto/sha256"
+	"fmt"
 	"io"
 	"io/ioutil"
 	"os"
@@ -48,3 +50,61 @@ func TestUnpackLayerDuplicateEntries(t *testing.T) {
 		t.Fatalf("Expected to fail with duplicate entry, got %v", err)
 	}
 }
+
+func TestUnpackLayer(t *testing.T) {
+	tmp1, err := ioutil.TempDir("", "test-layer")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(tmp1)
+	err = os.MkdirAll(filepath.Join(tmp1, "blobs", "sha256"), 0700)
+	if err != nil {
+		t.Fatal(err)
+	}
+	tarfile := filepath.Join(tmp1, "blobs", "sha256", "test.tar")
+	f, err := os.Create(tarfile)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	gw := gzip.NewWriter(f)
+	tw := tar.NewWriter(gw)
+
+	tw.WriteHeader(&tar.Header{Name: "test", Size: 4, Mode: 0600})
+	io.Copy(tw, bytes.NewReader([]byte("test")))
+	tw.Close()
+	gw.Close()
+	f.Close()
+
+	// generate sha256 hash
+	h := sha256.New()
+	file, err := os.Open(tarfile)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer file.Close()
+	_, err = io.Copy(h, file)
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = os.Rename(tarfile, filepath.Join(tmp1, "blobs", "sha256", fmt.Sprintf("%x", h.Sum(nil))))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	testManifest := manifest{
+		Layers: []descriptor{descriptor{
+			MediaType: "application/vnd.oci.image.layer.tar+gzip",
+			Digest:    fmt.Sprintf("sha256:%s", fmt.Sprintf("%x", h.Sum(nil))),
+		}},
+	}
+	err = testManifest.unpack(newPathWalker(tmp1), filepath.Join(tmp1, "rootfs"))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_, err = os.Stat(filepath.Join(tmp1, "rootfs", "test"))
+	if err != nil {
+		t.Fatal(err)
+	}
+}