Merge pull request #377 from docker/ensuring-set-meta-creates-parents

Ensure that SetMeta creates parent directory first

tuf/store/filestore.go

@@ -68,7 +68,15 @@ func (f *FilesystemStore) SetMultiMeta(metas map[string][]byte) error {
 func (f *FilesystemStore) SetMeta(name string, meta []byte) error {
 	fileName := fmt.Sprintf("%s.%s", name, f.metaExtension)
 	path := filepath.Join(f.metaDir, fileName)
-	if err := ioutil.WriteFile(path, meta, 0600); err != nil {
+
+	// Ensures the parent directories of the file we are about to write exist
+	err := os.MkdirAll(filepath.Dir(path), 0700)
+	if err != nil {
+		return err
+	}
+
+	// Write the file to disk
+	if err = ioutil.WriteFile(path, meta, 0600); err != nil {
 		return err
 	}
 	return nil

tuf/store/filestore_test.go

@@ -42,6 +42,21 @@ func TestSetMeta(t *testing.T) {
 	assert.Equal(t, testContent, content, "Content written to file was corrupted.")
 }
 
+func TestSetMetaWithNoParentDirectory(t *testing.T) {
+	s, err := NewFilesystemStore(testDir, "metadata", "json", "targets")
+	assert.Nil(t, err, "Initializing FilesystemStore returned unexpected error: %v", err)
+	defer os.RemoveAll(testDir)
+
+	testContent := []byte("test data")
+
+	err = s.SetMeta("noexist/"+"testMeta", testContent)
+	assert.Nil(t, err, "SetMeta returned unexpected error: %v", err)
+
+	content, err := ioutil.ReadFile(path.Join(testDir, "metadata", "noexist/testMeta.json"))
+	assert.Nil(t, err, "Error reading file: %v", err)
+	assert.Equal(t, testContent, content, "Content written to file was corrupted.")
+}
+
 func TestGetMeta(t *testing.T) {
 	s, err := NewFilesystemStore(testDir, "metadata", "json", "targets")
 	assert.Nil(t, err, "Initializing FilesystemStore returned unexpected error: %v", err)