Add '--yes' for openstack stack snapshot delete

Add optional arguments '--yes' or '-y' in osc cli `openstack stack
snapshot delete`. There is no judgement before use that cli
So propose to add it in case that we delete the snapshot unintentionally.
Closes-Bug: #1642874

Change-Id: If7b515dff64a18f56046b890279c2c59b0ab9dc7

heatclient/osc/v1/snapshot.py

@@ -14,6 +14,7 @@
 """Orchestration v1 Stack Snapshot implementations."""
 
 import logging
+import sys
 
 from osc_lib.command import command
 from osc_lib import exceptions as exc
@@ -192,11 +193,34 @@ class DeleteSnapshot(command.Command):
             metavar='<snapshot>',
             help=_('ID of stack snapshot')
         )
+        parser.add_argument(
+            '-y', '--yes',
+            action='store_true',
+            help=_('Skip yes/no prompt (assume yes)')
+        )
         return parser
 
     def take_action(self, parsed_args):
         self.log.debug('take_action(%s)' % parsed_args)
         heat_client = self.app.client_manager.orchestration
+        msg = ('User did not confirm snapshot delete '
+               '%sso taking no action.')
+        try:
+            if not parsed_args.yes and sys.stdin.isatty():
+                sys.stdout.write(
+                    _('Are you sure you want to delete the snapshot of this '
+                      'stack [Y/N]?'))
+                prompt_response = sys.stdin.readline().lower()
+                if not prompt_response.startswith('y'):
+                    self.log.info(msg, '')
+                    return
+        except KeyboardInterrupt:  # ctrl-c
+            self.log.info(msg, '(ctrl-c) ')
+            return
+        except EOFError:  # ctrl-d
+            self.log.info(msg, '(ctrl-d) ')
+            return
+
         try:
             heat_client.stacks.snapshot_delete(parsed_args.stack,
                                                parsed_args.snapshot)

heatclient/tests/unit/osc/v1/test_snapshot.py

@@ -10,8 +10,9 @@
 #   License for the specific language governing permissions and limitations
 #   under the License.
 #
-
+import mock
 from osc_lib import exceptions as exc
+import six
 
 from heatclient import exc as heat_exc
 from heatclient.osc.v1 import snapshot
@@ -157,3 +158,28 @@ class TestSnapshotDelete(TestStack):
             exc.CommandError,
             self.cmd.take_action,
             parsed_args)
+
+    @mock.patch('sys.stdin', spec=six.StringIO)
+    def test_snapshot_delete_prompt(self, mock_stdin):
+        arglist = ['my_stack', 'snapshot_id']
+        mock_stdin.isatty.return_value = True
+        mock_stdin.readline.return_value = 'y'
+        parsed_args = self.check_parser(self.cmd, arglist, [])
+
+        self.cmd.take_action(parsed_args)
+
+        mock_stdin.readline.assert_called_with()
+        self.stack_client.snapshot_delete.assert_called_with('my_stack',
+                                                             'snapshot_id')
+
+    @mock.patch('sys.stdin', spec=six.StringIO)
+    def test_snapshot_delete_prompt_no(self, mock_stdin):
+        arglist = ['my_stack', 'snapshot_id']
+        mock_stdin.isatty.return_value = True
+        mock_stdin.readline.return_value = 'n'
+        parsed_args = self.check_parser(self.cmd, arglist, [])
+
+        self.cmd.take_action(parsed_args)
+
+        mock_stdin.readline.assert_called_with()
+        self.stack_client.snapshot_delete.assert_not_called()