add functional regression test for bug #1888395

This change adds a funcitonal regression test that
assert the broken behavior when trying to live migrate
with a neutron backend that does not support multiple port
bindings.

Conflicts/Changes:
  nova/tests/functional/regressions/test_bug_1888395.py:
    - specify api major version to allow block_migration 'auto'
    - use TempDir fixture for instances path
    - worked around  lack of create_server and start_computes in integrated
      helpers in train by inlining the behavior in setUp and test_live_migrate
    - reverted to python2 compatiable super() syntax
  nova/tests/unit/virt/libvirt/fake_imagebackend.py:
    - include portion of change Ia3d7351c1805d98bcb799ab0375673c7f1cb8848
      which stubs out the is_file_in_instance_path method. That was
      included in a feature patch set so just pulling the necessary
      bit.

Change-Id: I470a016d35afe69809321bd67359f466c3feb90a
Partial-Bug: #1888395
(cherry picked from commit 71bc6fc9b89535679252ffe5a737eddad60e4102)
(cherry picked from commit bea55a7d45bdc97679cf08c9faec789cfc90de27)

nova/network/neutronv2/constants.py

@@ -19,6 +19,7 @@ VNIC_INDEX_EXT = 'VNIC Index'
 DNS_INTEGRATION = 'DNS Integration'
 MULTI_NET_EXT = 'Multi Provider Network'
 SUBSTR_PORT_FILTERING = 'IP address substring filtering'
+PORT_BINDING = 'Port Binding'
 PORT_BINDING_EXTENDED = 'Port Bindings Extended'
 LIVE_MIGRATION = 'live-migration'
 DEFAULT_SECGROUP = 'default'

nova/tests/functional/regressions/test_bug_1888395.py

@@ -0,0 +1,122 @@
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+import fixtures
+import mock
+
+from nova import context
+from nova.network.neutronv2 import api as neutron
+from nova.network.neutronv2 import constants as neutron_constants
+from nova.tests.functional import integrated_helpers
+from nova.tests.functional.libvirt import base as libvirt_base
+from nova.tests.unit.virt.libvirt import fake_os_brick_connector
+from nova.tests.unit.virt.libvirt import fakelibvirt
+
+
+class TestLiveMigrationWithoutMultiplePortBindings(
+        integrated_helpers.InstanceHelperMixin,
+        libvirt_base.ServersTestBase):
+    """Regression test for bug 1888395.
+
+    This regression test asserts that Live migration works when
+    neutron does not support the binding-extended api extension
+    and the legacy single port binding workflow is used.
+    """
+
+    ADMIN_API = True
+    api_major_version = 'v2.1'
+    microversion = 'latest'
+
+    def list_extensions(self, *args, **kwargs):
+        return {
+            'extensions': [
+                {
+                    # Copied from neutron-lib portbindings.py
+                    "updated": "2014-02-03T10:00:00-00:00",
+                    "name": neutron_constants.PORT_BINDING,
+                    "links": [],
+                    "alias": "binding",
+                    "description": "Expose port bindings of a virtual port to "
+                                   "external application"
+                }
+            ]
+        }
+
+    def setUp(self):
+        self.flags(instances_path=self.useFixture(fixtures.TempDir()).path)
+        super(TestLiveMigrationWithoutMultiplePortBindings, self).setUp()
+        self.neutron.list_extensions = self.list_extensions
+        self.neutron_api = neutron.API()
+        # TODO(sean-k-mooney): remove after
+        # I275509eb0e0eb9eaf26fe607b7d9a67e1edc71f8
+        # has merged.
+        self.useFixture(fixtures.MonkeyPatch(
+            'nova.virt.libvirt.driver.connector',
+            fake_os_brick_connector))
+
+        self.computes = {}
+        for host in ['start_host', 'end_host']:
+            host_info = fakelibvirt.HostInfo(
+                cpu_nodes=1, cpu_sockets=1, cpu_cores=4, cpu_threads=2,
+                kB_mem=10740000)
+            fake_connection = self._get_connection(
+                host_info=host_info, hostname=host)
+
+            # This is fun. Firstly we need to do a global'ish mock so we can
+            # actually start the service.
+            with mock.patch('nova.virt.libvirt.host.Host.get_connection',
+                            return_value=fake_connection):
+                compute = self.start_service('compute', host=host)
+
+            # Once that's done, we need to do some tweaks to each individual
+            # compute "service" to make sure they return unique objects
+            compute.driver._host.get_connection = lambda: fake_connection
+            self.computes[host] = compute
+
+        self.ctxt = context.get_admin_context()
+
+    def test_live_migrate(self):
+        flavors = self.api.get_flavors()
+        flavor = flavors[0]
+        server_req = self._build_minimal_create_server_request(
+            self.api, 'some-server', flavor_id=flavor['id'],
+            image_uuid='155d900f-4e14-4e4c-a73d-069cbf4541e6',
+            networks=[{'port': self.neutron.port_1['id']}])
+        server_req['availability_zone'] = 'nova:%s' % "start_host"
+        created_server = self.api.post_server({'server': server_req})
+        server = self._wait_for_state_change(
+            self.api, created_server, 'ACTIVE')
+        self.assertFalse(
+            self.neutron_api.supports_port_binding_extension(self.ctxt))
+        # TODO(sean-k-mooney): extend _live_migrate to support passing a host
+        self.api.post_server_action(
+            server['id'],
+            {
+                'os-migrateLive': {
+                    'host': 'end_host',
+                    'block_migration': 'auto'
+                }
+            }
+        )
+
+        # FIXME(sean-k-mooney): this should succeed but because of bug #188395
+        # it will fail.
+        # self._wait_for_server_parameter(
+        #     server, {'OS-EXT-SRV-ATTR:host': 'end_host', 'status': 'ACTIVE'})
+        # because of the bug the migration will fail in pre_live_migrate so
+        # the vm should still be active on the start_host
+        self._wait_for_server_parameter(
+            self.api, server,
+            {'OS-EXT-SRV-ATTR:host': 'start_host', 'status': 'ACTIVE'})
+
+        msg = "NotImplementedError: Cannot load 'vif_type' in the base class"
+        self.assertIn(msg, self.stdlog.logger.output)

nova/tests/unit/virt/libvirt/fake_imagebackend.py

@@ -184,11 +184,17 @@ class ImageBackendFixture(fixtures.Fixture):
         # class.
         image_init.SUPPORTS_CLONE = False
 
-        # Ditto for the 'is_shared_block_storage' function
+        # Ditto for the 'is_shared_block_storage' function and
+        # 'is_file_in_instance_path'
         def is_shared_block_storage():
             return False
 
+        def is_file_in_instance_path():
+            return False
+
         setattr(image_init, 'is_shared_block_storage', is_shared_block_storage)
+        setattr(image_init, 'is_file_in_instance_path',
+                is_file_in_instance_path)
 
         return image_init