Merge "Fix dropped check for boot_index 0 in _validate_bdm" into stab…

…le/queens

nova/compute/api.py

@@ -1286,6 +1286,11 @@ def _create_block_device_mapping(self, block_device_mapping):
 
     def _validate_bdm(self, context, instance, instance_type,
                       block_device_mappings, supports_multiattach=False):
+        def _subsequent_list(l):
+            # Each device which is capable of being used as boot device should
+            # be given a unique boot index, starting from 0 in ascending order.
+            return all(el + 1 == l[i + 1] for i, el in enumerate(l[:-1]))
+
         # Make sure that the boot indexes make sense.
         # Setting a negative value or None indicates that the device should not
         # be used for booting.
@@ -1294,9 +1299,7 @@ def _validate_bdm(self, context, instance, instance_type,
                                if bdm.boot_index is not None
                                and bdm.boot_index >= 0])
 
-        # Each device which is capable of being used as boot device should
-        # be given a unique boot index, starting from 0 in ascending order.
-        if any(i != v for i, v in enumerate(boot_indexes)):
+        if 0 not in boot_indexes or not _subsequent_list(boot_indexes):
             # Convert the BlockDeviceMappingList to a list for repr details.
             LOG.debug('Invalid block device mapping boot sequence for '
                       'instance: %s', list(block_device_mappings),

nova/tests/unit/compute/test_compute_api.py

@@ -4218,6 +4218,18 @@ def test_validate_bdm_with_error_volume_new_flow(self, mock_attach_create,
         mock_attach_create.assert_called_once_with(
             self.context, volume_id, instance.uuid)
 
+    def test_validate_bdm_missing_boot_index(self):
+        """Tests that _validate_bdm will fail if there is no boot_index=0 entry
+        """
+        bdms = objects.BlockDeviceMappingList(objects=[
+            objects.BlockDeviceMapping(
+                boot_index=None, image_id=uuids.image_id,
+                source_type='image', destination_type='volume')])
+        self.assertRaises(exception.InvalidBDMBootSequence,
+                          self.compute_api._validate_bdm,
+                          self.context, objects.Instance(), objects.Flavor(),
+                          bdms)
+
     def _test_provision_instances_with_cinder_error(self,
                                                     expected_exception):
         @mock.patch('nova.compute.utils.check_num_instances_quota')