Add --wait to server delete

This allows the server delete command to wait for the server to be
deleted (obviously).

The wait method is the same model that Tempest uses, i.e. wait for a 404
on server GET (successful deletion), fail if the server went to ERROR
status, or fail if a timeout is reached.  The default timeout of 300
seconds is also what Tempest uses.

Closes-Bug: #1460112

Change-Id: I0e66c400903e82832944d1cad61e7eb30177c3e8

Author: Matt Riedemann

doc/source/command-objects/server.rst

@@ -157,7 +157,11 @@ Delete server(s)
 .. code:: bash
 
     os server delete
-        <server> [<server> ...]
+        <server> [<server> ...] [--wait]
+
+.. option:: --wait
+
+    Wait for delete to complete
 
 .. describe:: <server>
 

openstackclient/common/utils.py

@@ -283,6 +283,52 @@ def wait_for_status(status_f,
     return retval
 
 
+def wait_for_delete(manager,
+                    res_id,
+                    status_field='status',
+                    sleep_time=5,
+                    timeout=300,
+                    callback=None):
+    """Wait for resource deletion
+
+    :param res_id: the resource id to watch
+    :param status_field: the status attribute in the returned resource object,
+        this is used to check for error states while the resource is being
+        deleted
+    :param sleep_time: wait this long between checks (seconds)
+    :param timeout: check until this long (seconds)
+    :param callback: called per sleep cycle, useful to display progress; this
+        function is passed a progress value during each iteration of the wait
+        loop
+    :rtype: True on success, False if the resource has gone to error state or
+        the timeout has been reached
+    """
+    total_time = 0
+    while total_time < timeout:
+        try:
+            # might not be a bad idea to re-use find_resource here if it was
+            # a bit more friendly in the exceptions it raised so we could just
+            # handle a NotFound exception here without parsing the message
+            res = manager.get(res_id)
+        except Exception as ex:
+            if type(ex).__name__ == 'NotFound':
+                return True
+            raise
+
+        status = getattr(res, status_field, '').lower()
+        if status == 'error':
+            return False
+
+        if callback:
+            progress = getattr(res, 'progress', None) or 0
+            callback(progress)
+        time.sleep(sleep_time)
+        total_time += sleep_time
+
+    # if we got this far we've timed out
+    return False
+
+
 def get_effective_log_level():
     """Returns the lowest logging level considered by logging handlers
 

openstackclient/compute/v2/server.py

@@ -572,6 +572,11 @@ def get_parser(self, prog_name):
             nargs="+",
             help=_('Server(s) to delete (name or ID)'),
         )
+        parser.add_argument(
+            '--wait',
+            action='store_true',
+            help=_('Wait for delete to complete'),
+        )
         return parser
 
     def take_action(self, parsed_args):
@@ -581,6 +586,18 @@ def take_action(self, parsed_args):
             server_obj = utils.find_resource(
                 compute_client.servers, server)
             compute_client.servers.delete(server_obj.id)
+            if parsed_args.wait:
+                if utils.wait_for_delete(
+                    compute_client.servers,
+                    server_obj.id,
+                    callback=_show_progress,
+                ):
+                    sys.stdout.write('\n')
+                else:
+                    self.log.error(_('Error deleting server: %s'),
+                                   server_obj.id)
+                    sys.stdout.write(_('\nError deleting server'))
+                    raise SystemExit
         return
 
 

openstackclient/tests/common/test_utils.py

@@ -13,6 +13,9 @@
 #   under the License.
 #
 
+import time
+import uuid
+
 import mock
 
 from openstackclient.common import exceptions
@@ -120,6 +123,42 @@ def test_sort_items_with_invalid_direction(self):
                           utils.sort_items,
                           items, sort_str)
 
+    @mock.patch.object(time, 'sleep')
+    def test_wait_for_delete_ok(self, mock_sleep):
+        # Tests the normal flow that the resource is deleted with a 404 coming
+        # back on the 2nd iteration of the wait loop.
+        resource = mock.MagicMock(status='ACTIVE', progress=None)
+        mock_get = mock.Mock(side_effect=[resource,
+                                          exceptions.NotFound(404)])
+        manager = mock.MagicMock(get=mock_get)
+        res_id = str(uuid.uuid4())
+        callback = mock.Mock()
+        self.assertTrue(utils.wait_for_delete(manager, res_id,
+                                              callback=callback))
+        mock_sleep.assert_called_once_with(5)
+        callback.assert_called_once_with(0)
+
+    @mock.patch.object(time, 'sleep')
+    def test_wait_for_delete_timeout(self, mock_sleep):
+        # Tests that we fail if the resource is not deleted before the timeout.
+        resource = mock.MagicMock(status='ACTIVE')
+        mock_get = mock.Mock(return_value=resource)
+        manager = mock.MagicMock(get=mock_get)
+        res_id = str(uuid.uuid4())
+        self.assertFalse(utils.wait_for_delete(manager, res_id, sleep_time=1,
+                                               timeout=1))
+        mock_sleep.assert_called_once_with(1)
+
+    @mock.patch.object(time, 'sleep')
+    def test_wait_for_delete_error(self, mock_sleep):
+        # Tests that we fail if the resource goes to error state while waiting.
+        resource = mock.MagicMock(status='ERROR')
+        mock_get = mock.Mock(return_value=resource)
+        manager = mock.MagicMock(get=mock_get)
+        res_id = str(uuid.uuid4())
+        self.assertFalse(utils.wait_for_delete(manager, res_id))
+        self.assertFalse(mock_sleep.called)
+
 
 class NoUniqueMatch(Exception):
     pass

openstackclient/tests/compute/v2/test_server.py

@@ -16,6 +16,7 @@
 import copy
 import mock
 
+from openstackclient.common import utils as common_utils
 from openstackclient.compute.v2 import server
 from openstackclient.tests.compute.v2 import fakes as compute_fakes
 from openstackclient.tests import fakes
@@ -319,6 +320,52 @@ def test_server_delete_no_options(self):
             compute_fakes.server_id,
         )
 
+    @mock.patch.object(common_utils, 'wait_for_delete', return_value=True)
+    def test_server_delete_wait_ok(self, mock_wait_for_delete):
+        arglist = [
+            compute_fakes.server_id, '--wait'
+        ]
+        verifylist = [
+            ('servers', [compute_fakes.server_id]),
+        ]
+        parsed_args = self.check_parser(self.cmd, arglist, verifylist)
+
+        # DisplayCommandBase.take_action() returns two tuples
+        self.cmd.take_action(parsed_args)
+
+        self.servers_mock.delete.assert_called_with(
+            compute_fakes.server_id,
+        )
+
+        mock_wait_for_delete.assert_called_once_with(
+            self.servers_mock,
+            compute_fakes.server_id,
+            callback=server._show_progress
+        )
+
+    @mock.patch.object(common_utils, 'wait_for_delete', return_value=False)
+    def test_server_delete_wait_fails(self, mock_wait_for_delete):
+        arglist = [
+            compute_fakes.server_id, '--wait'
+        ]
+        verifylist = [
+            ('servers', [compute_fakes.server_id]),
+        ]
+        parsed_args = self.check_parser(self.cmd, arglist, verifylist)
+
+        # DisplayCommandBase.take_action() returns two tuples
+        self.assertRaises(SystemExit, self.cmd.take_action, parsed_args)
+
+        self.servers_mock.delete.assert_called_with(
+            compute_fakes.server_id,
+        )
+
+        mock_wait_for_delete.assert_called_once_with(
+            self.servers_mock,
+            compute_fakes.server_id,
+            callback=server._show_progress
+        )
+
 
 class TestServerImageCreate(TestServer):