Generate a full backup first time

If there isn't any backup of the specified volume, generate a full
backup, but not an incremental one.

Closes-Bug: #1563245
Change-Id: If30e0292671e2be8d026006986b942206cfd2435

freezer/openstack/backup.py

@@ -114,5 +114,14 @@ class BackupOs:
     def backup_cinder(self, volume_id, name=None, description=None):
         client_manager = self.client_manager
         cinder = client_manager.get_cinder()
+        search_opts = {
+            'volume_id': volume_id,
+            'status': 'available',
+        }
+        backups = cinder.backups.list(search_opts=search_opts)
+        if len(backups) > 0 :
+            incremental = True
+        else:
+            incremental = False
         cinder.backups.create(volume_id, self.container, name, description,
-                              incremental=True, force=True)
+                              incremental=incremental, force=True)

setup.cfg

@@ -1,6 +1,6 @@
 [metadata]
 name = freezer
-version = 2.0.0
+version = 2.1.0
 author = Freezer Team
 author-email = openstack-dev@lists.openstack.org
 summary = The OpenStack Backup Restore and Disaster Recovery as a Service Platform