Always add parent directories of files to snapshots.

pkg/snapshot/snapshot.go

@@ -226,10 +226,28 @@ func writeToTar(t util.Tar, files, whiteouts []string) error {
 			return err
 		}
 	}
+
+	addedPaths := make(map[string]bool)
 	for _, path := range files {
+		if _, fileExists := addedPaths[path]; fileExists {
+			continue
+		}
+		for _, parentPath := range util.ParentDirectories(path) {
+			if parentPath == "/" {
+				continue
+			}
+			if _, dirExists := addedPaths[parentPath]; dirExists {
+				continue
+			}
+			if err := t.AddFileToTar(parentPath); err != nil {
+				return err
+			}
+			addedPaths[parentPath] = true
+		}
 		if err := t.AddFileToTar(path); err != nil {
 			return err
 		}
+		addedPaths[path] = true
 	}
 	return nil
 }

pkg/snapshot/snapshot_test.go

@@ -64,6 +64,12 @@ func TestSnapshotFSFileChange(t *testing.T) {
 		fooPath: "newbaz1",
 		batPath: "baz",
 	}
+	for _, path := range util.ParentDirectoriesWithoutLeadingSlash(batPath) {
+		if path == "/" {
+			continue
+		}
+		snapshotFiles[path+"/"] = ""
+	}
 
 	actualFiles := []string{}
 	for {
@@ -77,6 +83,9 @@ func TestSnapshotFSFileChange(t *testing.T) {
 		if _, isFile := snapshotFiles[hdr.Name]; !isFile {
 			t.Fatalf("File %s unexpectedly in tar", hdr.Name)
 		}
+		if hdr.Typeflag == tar.TypeDir {
+			continue
+		}
 		contents, _ := ioutil.ReadAll(tr)
 		if string(contents) != snapshotFiles[hdr.Name] {
 			t.Fatalf("Contents of %s incorrect, expected: %s, actual: %s", hdr.Name, snapshotFiles[hdr.Name], string(contents))
@@ -153,6 +162,12 @@ func TestSnapshotFSChangePermissions(t *testing.T) {
 	snapshotFiles := map[string]string{
 		batPathWithoutLeadingSlash: "baz2",
 	}
+	for _, path := range util.ParentDirectoriesWithoutLeadingSlash(batPathWithoutLeadingSlash) {
+		if path == "/" {
+			continue
+		}
+		snapshotFiles[path+"/"] = ""
+	}
 
 	foundFiles := []string{}
 	for {
@@ -164,6 +179,9 @@ func TestSnapshotFSChangePermissions(t *testing.T) {
 		if _, isFile := snapshotFiles[hdr.Name]; !isFile {
 			t.Fatalf("File %s unexpectedly in tar", hdr.Name)
 		}
+		if hdr.Typeflag == tar.TypeDir {
+			continue
+		}
 		contents, _ := ioutil.ReadAll(tr)
 		if string(contents) != snapshotFiles[hdr.Name] {
 			t.Fatalf("Contents of %s incorrect, expected: %s, actual: %s", hdr.Name, snapshotFiles[hdr.Name], string(contents))
@@ -203,7 +221,9 @@ func TestSnapshotFiles(t *testing.T) {
 	expectedFiles := []string{
 		filepath.Join(testDirWithoutLeadingSlash, "foo"),
 	}
-	expectedFiles = append(expectedFiles, util.ParentDirectoriesWithoutLeadingSlash(filepath.Join(testDir, "foo"))...)
+	for _, path := range util.ParentDirectoriesWithoutLeadingSlash(filepath.Join(testDir, "foo")) {
+		expectedFiles = append(expectedFiles, strings.TrimRight(path, "/")+"/")
+	}
 
 	f, err := os.Open(tarPath)
 	if err != nil {

pkg/util/fs_util.go

@@ -468,10 +468,10 @@ func ParentDirectories(path string) []string {
 		}
 		dir, _ = filepath.Split(dir)
 		dir = filepath.Clean(dir)
-		paths = append(paths, dir)
+		paths = append([]string{dir}, paths...)
 	}
 	if len(paths) == 0 {
-		paths = append(paths, config.RootDir)
+		paths = []string{config.RootDir}
 	}
 	return paths
 }

pkg/util/fs_util_test.go

@@ -213,8 +213,6 @@ func Test_ParentDirectories(t *testing.T) {
 			defer func() { config.RootDir = original }()
 			config.RootDir = tt.rootDir
 			actual := ParentDirectories(tt.path)
-			sort.Strings(actual)
-			sort.Strings(tt.expected)
 
 			testutil.CheckErrorAndDeepEqual(t, false, nil, tt.expected, actual)
 		})

pkg/util/tar_util.go

@@ -85,6 +85,9 @@ func (t *Tar) AddFileToTar(p string) error {
 		hdr.Name = strings.TrimPrefix(p, config.RootDir)
 		hdr.Name = strings.TrimLeft(hdr.Name, "/")
 	}
+	if hdr.Typeflag == tar.TypeDir && !strings.HasSuffix(hdr.Name, "/") {
+		hdr.Name = hdr.Name + "/"
+	}
 	// rootfs may not have been extracted when using cache, preventing uname/gname from resolving
 	// this makes this layer unnecessarily differ from a cached layer which does contain this information
 	hdr.Uname = ""