Add arg to remove config-dir for config-download

Adds an argument to config-download that removes the config-dir and
contents before downloading the config, if it exists.

Related-Bug: 1752118
Depends-On: Ie00f71b12f56262985c47810be0e80402e9e558e
Depends-On: Ibb59b044dc0c14bf48dc3d500536195230414c81
Change-Id: I68a72e11dd66d8d5100512683633caa2174f9e6b

tripleoclient/tests/v1/overcloud_config/test_overcloud_config.py

@@ -32,9 +32,24 @@ class TestOvercloudConfig(utils.TestCommand):
         arglist = ['--name', 'overcloud', '--config-dir', '/tmp']
         verifylist = [
             ('name', 'overcloud'),
-            ('config_dir', '/tmp')
+            ('config_dir', '/tmp'),
+            ('preserve_config_dir', True)
         ]
 
         parsed_args = self.check_parser(self.cmd, arglist, verifylist)
         self.cmd.take_action(parsed_args)
-        mock_config.assert_called_once_with('overcloud', '/tmp', None)
+        mock_config.assert_called_once_with('overcloud', '/tmp', None, True)
+
+    @mock.patch('tripleo_common.utils.config.Config.download_config')
+    def test_overcloud_download_config_no_preserve(self, mock_config):
+        arglist = ['--name', 'overcloud', '--config-dir', '/tmp',
+                   '--no-preserve-config']
+        verifylist = [
+            ('name', 'overcloud'),
+            ('config_dir', '/tmp'),
+            ('preserve_config_dir', False)
+        ]
+
+        parsed_args = self.check_parser(self.cmd, arglist, verifylist)
+        self.cmd.take_action(parsed_args)
+        mock_config.assert_called_once_with('overcloud', '/tmp',  None, False)

tripleoclient/v1/overcloud_config.py

@@ -49,6 +49,16 @@ class DownloadConfig(command.Command):
             help=_('Type of object config to be extract from the deployment, '
                    'defaults to all keys available'),
         )
+        parser.add_argument(
+            '--no-preserve-config',
+            dest='preserve_config_dir',
+            action='store_false',
+            default=True,
+            help=('If specified, will delete and recreate the --config-dir '
+                  'if it already exists. Default is to use the existing dir '
+                  'location and overwrite files. Files in --config-dir not '
+                  'from the stack will be preserved by default.')
+        )
         return parser
 
     def take_action(self, parsed_args):
@@ -59,8 +69,10 @@ class DownloadConfig(command.Command):
         name = parsed_args.name
         config_dir = parsed_args.config_dir
         config_type = parsed_args.config_type
+        preserve_config_dir = parsed_args.preserve_config_dir
         # Get config
         config = ooo_config.Config(clients.orchestration)
-        config_path = config.download_config(name, config_dir, config_type)
+        config_path = config.download_config(name, config_dir, config_type,
+                                             preserve_config_dir)
         print("The TripleO configuration has been successfully generated "
               "into: {0}".format(config_path))