runtime: Let MockFSInit create a mock fs driver at any path

Currently MockFSInit always creates the mockfs at the fixed path
/tmp/vc/mockfs.  This change allows it to be initialized at any path
given as a parameter.  This allows the tests in fs_test.go to be
simplified, because the by using a temporary directory from
t.TempDir(), which is automatically cleaned up, we don't need to
manually trigger initTestDir() (which is misnamed, it's actually a
cleanup function).

For now we still use the fixed path when auto-creating the mockfs in
MockAutoInit(), but we'll change that later.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

src/runtime/virtcontainers/persist/fs/fs_test.go

@@ -14,8 +14,8 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
-func getFsDriver() (*FS, error) {
+func getFsDriver(t *testing.T) (*FS, error) {
-	driver, err := MockFSInit()
+	driver, err := MockFSInit(t.TempDir())
 	if err != nil {
 		return nil, fmt.Errorf("failed to init fs driver")
 	}
@@ -27,16 +27,8 @@ func getFsDriver() (*FS, error) {
 	return fs.FS, nil
 }
 
-func initTestDir() func() {
-	return func() {
-		os.RemoveAll(MockStorageRootPath())
-	}
-}
-
 func TestFsLockShared(t *testing.T) {
-	defer initTestDir()()
+	fs, err := getFsDriver(t)
-
-	fs, err := getFsDriver()
 	assert.Nil(t, err)
 	assert.NotNil(t, fs)
 
@@ -61,9 +53,7 @@ func TestFsLockShared(t *testing.T) {
 }
 
 func TestFsLockExclusive(t *testing.T) {
-	defer initTestDir()()
+	fs, err := getFsDriver(t)
-
-	fs, err := getFsDriver()
 	assert.Nil(t, err)
 	assert.NotNil(t, fs)
 
@@ -89,9 +79,7 @@ func TestFsLockExclusive(t *testing.T) {
 }
 
 func TestFsDriver(t *testing.T) {
-	defer initTestDir()()
+	fs, err := getFsDriver(t)
-
-	fs, err := getFsDriver()
 	assert.Nil(t, err)
 	assert.NotNil(t, fs)
 
@@ -162,12 +150,10 @@ func TestFsDriver(t *testing.T) {
 }
 
 func TestGlobalReadWrite(t *testing.T) {
-	defer initTestDir()()
-
 	relPath := "test/123/aaa.json"
 	data := "hello this is testing global read write"
 
-	fs, err := getFsDriver()
+	fs, err := getFsDriver(t)
 	assert.Nil(t, err)
 	assert.NotNil(t, fs)
 

src/runtime/virtcontainers/persist/fs/mockfs.go

@@ -36,7 +36,7 @@ func MockRunVMStoragePath() string {
 	return filepath.Join(MockStorageRootPath(), vmPathSuffix)
 }
 
-func MockFSInit() (persistapi.PersistDriver, error) {
+func MockFSInit(rootPath string) (persistapi.PersistDriver, error) {
 	driver, err := Init()
 	if err != nil {
 		return nil, fmt.Errorf("Could not create Mock FS driver: %v", err)
@@ -47,7 +47,7 @@ func MockFSInit() (persistapi.PersistDriver, error) {
 		return nil, fmt.Errorf("Could not create Mock FS driver")
 	}
 
-	fsDriver.storageRootPath = MockStorageRootPath()
+	fsDriver.storageRootPath = rootPath
 	fsDriver.driverName = "mockfs"
 
 	return &MockFS{fsDriver}, nil
@@ -55,7 +55,7 @@ func MockFSInit() (persistapi.PersistDriver, error) {
 
 func MockAutoInit() (persistapi.PersistDriver, error) {
 	if mockTesting {
-		return MockFSInit()
+		return MockFSInit(MockStorageRootPath())
 	}
 	return nil, nil
 }

src/runtime/virtcontainers/persist/fs/mockfs_test.go

@@ -28,7 +28,7 @@ func TestMockAutoInit(t *testing.T) {
 	mockTesting = true
 	fsd, err = MockAutoInit()
 	assert.NoError(err)
-	expectedFS, err := MockFSInit()
+	expectedFS, err := MockFSInit(MockStorageRootPath())
 	assert.NoError(err)
 	assert.Equal(expectedFS, fsd)
 }