Make set_configs.py work with symlinks

Closes-Bug: #1702305

Change-Id: I92a404b8d301937dc1847d42576e30db43951990

docker/base/set_configs.py

@@ -75,12 +75,16 @@ class ConfigFile(object):
         self._delete_path(dest)
         # dest endswith / means copy the <source> to <dest> folder
         LOG.info('Copying %s to %s', source, dest)
-        shutil.copy(source, dest)
-        self._set_properties(source, dest)
+        if os.path.islink(source):
+            link_target = os.readlink(source)
+            os.symlink(link_target, dest)
+        else:
+            shutil.copy(source, dest)
+            self._set_properties(source, dest)
 
     def _merge_directories(self, source, dest):
         if os.path.isdir(source):
-            if os.path.exists(dest) and not os.path.isdir(dest):
+            if os.path.lexists(dest) and not os.path.isdir(dest):
                 self._delete_path(dest)
             if not os.path.isdir(dest):
                 LOG.info('Creating directory %s', dest)
@@ -95,7 +99,7 @@ class ConfigFile(object):
             self._copy_file(source, dest)
 
     def _delete_path(self, path):
-        if not os.path.exists(path):
+        if not os.path.lexists(path):
             return
         LOG.info('Deleting %s', path)
         if os.path.isdir(path):

tests/test_set_config.py

@@ -77,41 +77,41 @@ FAKE_CONFIG_FILE = FAKE_CONFIG_FILES[0]
 
 class ConfigFileTest(base.BaseTestCase):
 
-    @mock.patch('os.path.exists', return_value=False)
-    def test_delete_path_not_exists(self, mock_exists):
+    @mock.patch('os.path.lexists', return_value=False)
+    def test_delete_path_not_exists(self, mock_lexists):
 
         config_file = copy.deepcopy(FAKE_CONFIG_FILE)
         config_file._delete_path(config_file.dest)
 
-        mock_exists.assert_called_with(config_file.dest)
+        mock_lexists.assert_called_with(config_file.dest)
 
-    @mock.patch('os.path.exists', return_value=True)
+    @mock.patch('os.path.lexists', return_value=True)
     @mock.patch('os.path.isdir', return_value=True)
     @mock.patch('shutil.rmtree')
     def test_delete_path_exist_dir(self,
                                    mock_rmtree,
                                    mock_isdir,
-                                   mock_exists):
+                                   mock_lexists):
 
         config_file = copy.deepcopy(FAKE_CONFIG_FILE)
         config_file._delete_path(config_file.dest)
 
-        mock_exists.assert_called_with(config_file.dest)
+        mock_lexists.assert_called_with(config_file.dest)
         mock_isdir.assert_called_with(config_file.dest)
         mock_rmtree.assert_called_with(config_file.dest)
 
-    @mock.patch('os.path.exists', return_value=True)
+    @mock.patch('os.path.lexists', return_value=True)
     @mock.patch('os.path.isdir', return_value=False)
     @mock.patch('os.remove')
     def test_delete_path_exist_file(self,
                                     mock_remove,
                                     mock_isdir,
-                                    mock_exists):
+                                    mock_lexists):
 
         config_file = copy.deepcopy(FAKE_CONFIG_FILE)
         config_file._delete_path(config_file.dest)
 
-        mock_exists.assert_called_with(config_file.dest)
+        mock_lexists.assert_called_with(config_file.dest)
         mock_isdir.assert_called_with(config_file.dest)
         mock_remove.assert_called_with(config_file.dest)