remove the CONF.allow_migrate_to_same_host

When running the "migrate" operation and the
CONF.allow_resize_to_same_host is set as "false",
the CONF.allow_migrate_to_same_host doesn't work
in the function 'resize' from nova/compute/api.py.
At the same time, there is no checking the
CONF.allow_migrate_to_same_host in the function
_prep_resize from nova/compute/manager.py

DocImpact: remove the CONF.allow_migrate_to_same_host
Change-Id: I4c54c7c6e0e5e37cc46c52350ba4ce2047325ef9
Closes-Bug: #1364851

nova/compute/api.py

@@ -88,10 +88,6 @@
                 default=False,
                 help='Allow destination machine to match source for resize. '
                      'Useful when testing in single-host environments.'),
-    cfg.BoolOpt('allow_migrate_to_same_host',
-                default=False,
-                help='Allow migrate machine to the same host. '
-                     'Useful when testing in single-host environments.'),
     cfg.StrOpt('default_schedule_zone',
                help='Availability zone to use when user doesn\'t specify one'),
     cfg.ListOpt('non_inheritable_image_properties',
@@ -2661,10 +2657,6 @@ def resize(self, context, instance, flavor_id=None, clean_shutdown=True,
         if not CONF.allow_resize_to_same_host:
             filter_properties['ignore_hosts'].append(instance.host)
 
-        # Here when flavor_id is None, the process is considered as migrate.
-        if (not flavor_id and not CONF.allow_migrate_to_same_host):
-            filter_properties['ignore_hosts'].append(instance.host)
-
         if self.cell_type == 'api':
             # Commit reservations early and create migration record.
             self._resize_cells_support(context, quotas, instance,

nova/compute/manager.py

@@ -3685,7 +3685,13 @@ def _prep_resize(self, context, image, instance, instance_type,
             raise exception.MigrationError(reason=msg)
 
         same_host = instance.host == self.host
-        if same_host and not CONF.allow_resize_to_same_host:
+        # if the flavor IDs match, it's migrate; otherwise resize
+        if same_host and instance_type['id'] == instance['instance_type_id']:
+            # check driver whether support migrate to same host
+            if not self.driver.capabilities['supports_migrate_to_same_host']:
+                raise exception.UnableToMigrateToSelf(
+                    instance_id=instance.uuid, host=self.host)
+        elif same_host and not CONF.allow_resize_to_same_host:
             self._set_instance_error_state(context, instance)
             msg = _('destination same as source!')
             raise exception.MigrationError(reason=msg)

nova/tests/unit/compute/test_compute_api.py

@@ -1375,16 +1375,14 @@ def test_revert_resize_concurent_fail(self):
 
     def _test_resize(self, flavor_id_passed=True,
                      same_host=False, allow_same_host=False,
-                     allow_mig_same_host=False,
                      project_id=None,
                      extra_kwargs=None,
                      same_flavor=False,
                      clean_shutdown=True):
         if extra_kwargs is None:
             extra_kwargs = {}
 
-        self.flags(allow_resize_to_same_host=allow_same_host,
-                   allow_migrate_to_same_host=allow_mig_same_host)
+        self.flags(allow_resize_to_same_host=allow_same_host)
 
         params = {}
         if project_id is not None:
@@ -1441,8 +1439,6 @@ def _check_state(expected_task_state=None):
             else:
                 filter_properties = {'ignore_hosts': [fake_inst['host']]}
 
-            if not flavor_id_passed and not allow_mig_same_host:
-                filter_properties['ignore_hosts'].append(fake_inst['host'])
             if flavor_id_passed:
                 expected_reservations = fake_quotas.reservations
             else:

nova/tests/unit/virt/vmwareapi/test_driver_api.py

@@ -307,6 +307,8 @@ def test_cleanup_host(self):
     def test_driver_capabilities(self):
         self.assertTrue(self.conn.capabilities['has_imagecache'])
         self.assertFalse(self.conn.capabilities['supports_recreate'])
+        self.assertTrue(
+            self.conn.capabilities['supports_migrate_to_same_host'])
 
     def test_configuration_linked_clone(self):
         self.flags(use_linked_clone=None, group='vmware')

nova/virt/driver.py

@@ -136,7 +136,8 @@ class ComputeDriver(object):
     capabilities = {
         "has_imagecache": False,
         "supports_recreate": False,
-        }
+        "supports_migrate_to_same_host": False
+    }
 
     def __init__(self, virtapi):
         self.virtapi = virtapi

nova/virt/fake.py

@@ -90,6 +90,7 @@ class FakeDriver(driver.ComputeDriver):
     capabilities = {
         "has_imagecache": True,
         "supports_recreate": True,
+        "supports_migrate_to_same_host": True
         }
 
     # Since we don't have a real hypervisor, pretend we have lots of

nova/virt/ironic/driver.py

@@ -159,7 +159,8 @@ class IronicDriver(virt_driver.ComputeDriver):
     """Hypervisor driver for Ironic - bare metal provisioning."""
 
     capabilities = {"has_imagecache": False,
-                    "supports_recreate": False}
+                    "supports_recreate": False,
+                    "supports_migrate_to_same_host": False}
 
     def __init__(self, virtapi, read_only=False):
         super(IronicDriver, self).__init__(virtapi)

nova/virt/libvirt/driver.py

@@ -382,11 +382,11 @@ def repr_method(self):
 
 
 class LibvirtDriver(driver.ComputeDriver):
-
     capabilities = {
         "has_imagecache": True,
         "supports_recreate": True,
-        }
+        "supports_migrate_to_same_host": False
+    }
 
     def __init__(self, virtapi, read_only=False):
         super(LibvirtDriver, self).__init__(virtapi)

nova/virt/vmwareapi/driver.py

@@ -109,7 +109,8 @@ class VMwareVCDriver(driver.ComputeDriver):
     capabilities = {
         "has_imagecache": True,
         "supports_recreate": False,
-        }
+        "supports_migrate_to_same_host": True
+    }
 
     # The vCenter driver includes API that acts on ESX hosts or groups
     # of ESX hosts in clusters or non-cluster logical-groupings.