Allow "cinder backup-delete" to delete multiple backups in one request

While "cinder snapshot-delete" and "cinder delete" allow multiple resources to be deleted in a single command, "cinder backup-delete" request can only delete one backup at a time. Adding this capability to backups in cinderclient. Enables "cinder backup-delete" to delete multiple backups in a single command.

With this change the command can be run as below:

cinder backup-delete <backup> [<backup>...]

DocImpact
Closes-Bug: #1543056
Implements: blueprint cli-backup-multiple-deletes

Change-Id: I767710bda3b7c358c6525c9a9f074010084e411d

cinderclient/tests/unit/v2/fakes.py

@@ -806,6 +806,12 @@ class FakeHTTPClient(base_client.HTTPClient):
     def delete_backups_76a17945_3c6f_435c_975b_b5685db10b62(self, **kw):
         return (202, {}, None)
 
+    def delete_backups_1234(self, **kw):
+        return (202, {}, None)
+
+    def delete_backups_5678(self, **kw):
+        return (202, {}, None)
+
     def post_backups(self, **kw):
         base_uri = 'http://localhost:8776'
         tenant_id = '0fa851f6668144cf9cd8c8419c1646c1'

cinderclient/tests/unit/v2/test_shell.py

@@ -415,6 +415,11 @@ class ShellTest(utils.TestCase):
         self.run_command('backup-create 1234 --snapshot-id 4321')
         self.assert_called('POST', '/backups')
 
+    def test_multiple_backup_delete(self):
+        self.run_command('backup-delete 1234 5678')
+        self.assert_called_anytime('DELETE', '/backups/1234')
+        self.assert_called('DELETE', '/backups/5678')
+
     def test_restore(self):
         self.run_command('backup-restore 1234')
         self.assert_called('POST', '/backups/1234/restore')

cinderclient/v2/shell.py

@@ -1472,13 +1472,22 @@ def do_backup_list(cs, args):
     utils.print_list(backups, columns)
 
 
-@utils.arg('backup', metavar='<backup>',
-           help='Name or ID of backup to delete.')
+@utils.arg('backup', metavar='<backup>', nargs='+',
+           help='Name or ID of backup(s) to delete.')
 @utils.service_type('volumev2')
 def do_backup_delete(cs, args):
-    """Removes a backup."""
-    backup = _find_backup(cs, args.backup)
-    backup.delete()
+    """Removes one or more backups."""
+    failure_count = 0
+    for backup in args.backup:
+        try:
+            _find_backup(cs, backup).delete()
+            print("Request to delete backup %s has been accepted." % (backup))
+        except Exception as e:
+            failure_count += 1
+            print("Delete for backup %s failed: %s" % (backup, e))
+    if failure_count == len(args.backup):
+        raise exceptions.CommandError("Unable to delete any of the specified "
+                                      "backups.")
 
 
 @utils.arg('backup', metavar='<backup>',