Added --overwrite parameter for removing all files from restore directory.

Default value --overwrite=False

Change-Id: I5c1aea7000c888b966c2b6e57d22744e35fbdfae
Closes-bug: #1544713

freezer/common/config.py

@@ -62,7 +62,8 @@ DEFAULT_PARAMS = {
     'mode': 'fs', 'action': 'backup', 'shadow': '', 'shadow_path': '',
     'windows_volume': '', 'command': None, 'metadata_out': False,
     'storage': 'swift', 'ssh_key': '', 'ssh_username': '', 'ssh_host': '',
-    'ssh_port': DEFAULT_SSH_PORT, 'compression': 'gzip'
+    'ssh_port': DEFAULT_SSH_PORT, 'compression': 'gzip',
+    'overwrite': False,
 }
 
 
@@ -332,8 +333,11 @@ _COMMON = [
                dest='config',
                help="Config file abs path. Option arguments are provided from "
                     "config file. When config file is used any option from "
-                    "command line provided take precedence."
-               )
+                    "command line provided take precedence."),
+    cfg.BoolOpt('overwrite',
+                dest='overwrite',
+                help='With overwrite removes files from restore path before '
+                     'restore.'),
 ]
 
 

freezer/engine/engine.py

@@ -115,12 +115,16 @@ class BackupEngine(object):
                 break
             time.sleep(1)
 
-    def restore(self, backup, restore_path):
+    def restore(self, backup, restore_path, overwrite):
         """
         :type backup: freezer.storage.Backup
         """
         logging.info("Creation restore path: {0}".format(restore_path))
         utils.create_dir_tree(restore_path)
+        if not overwrite and not utils.is_empty_dir(restore_path):
+            raise Exception(
+                "Restore dir is not empty. "
+                "Please use --overwrite or provide different path.")
         logging.info("Creation restore path completed")
         for level in range(0, backup.level + 1):
             b = backup.full_backup.increments[level]

freezer/job.py

@@ -185,7 +185,7 @@ class RestoreJob(Job):
             backup = self.storage.find_one(conf.hostname_backup_name,
                                            restore_timestamp)
 
-            self.engine.restore(backup, restore_abs_path)
+            self.engine.restore(backup, restore_abs_path, conf.overwrite)
             return {}
 
         res = restore.RestoreOs(conf.client_manager, conf.container)

freezer/utils/utils.py

@@ -44,6 +44,10 @@ def create_dir_tree(dir):
             raise exc
 
 
+def is_empty_dir(path):
+    return not os.listdir(path)
+
+
 def create_dir(directory, do_log=True):
     """
     Creates a directory if it doesn't exists and write the execution