From bf713ac7e1a761d031cfb49c5b6e888f788ad7ff Mon Sep 17 00:00:00 2001
From: licanwei <li.canwei2@zte.com.cn>
Date: Sun, 15 Oct 2017 20:22:13 -0700
Subject: [PATCH] Optimize live_migrate_instance

https://github.com/openstack/python-novaclient/blob/
master/novaclient/v2/servers.py#L468
From nova api version 2.25(Mitaka release), the default value of
block_migration is None which is mapped to 'auto'.
So we can remove 'block_migration' from live_migrate_instance.

Change-Id: I75a581d3146824b1146e2acf5a7fbe4f8368a4e8
---
 watcher/applier/actions/migration.py          | 15 ++--------
 watcher/common/nova_helper.py                 |  9 +++---
 .../tests/applier/actions/test_migration.py   | 28 -------------------
 3 files changed, 7 insertions(+), 45 deletions(-)

diff --git a/watcher/applier/actions/migration.py b/watcher/applier/actions/migration.py
index 07eb83a3a..d0b6dcf3d 100644
--- a/watcher/applier/actions/migration.py
+++ b/watcher/applier/actions/migration.py
@@ -112,18 +112,9 @@ class Migrate(base.BaseAction):
             result = nova.live_migrate_instance(instance_id=self.instance_uuid,
                                                 dest_hostname=destination)
         except nova_helper.nvexceptions.ClientException as e:
-            if e.code == 400:
-                LOG.debug("Live migration of instance %s failed. "
-                          "Trying to live migrate using block migration."
-                          % self.instance_uuid)
-                result = nova.live_migrate_instance(
-                    instance_id=self.instance_uuid,
-                    dest_hostname=destination,
-                    block_migration=True)
-            else:
-                LOG.debug("Nova client exception occurred while live "
-                          "migrating instance %s.Exception: %s" %
-                          (self.instance_uuid, e))
+            LOG.debug("Nova client exception occurred while live "
+                      "migrating instance %s.Exception: %s" %
+                      (self.instance_uuid, e))
         except Exception as e:
             LOG.exception(e)
             LOG.critical("Unexpected error occurred. Migration failed for "
diff --git a/watcher/common/nova_helper.py b/watcher/common/nova_helper.py
index 8bc08a59b..55a1aff94 100644
--- a/watcher/common/nova_helper.py
+++ b/watcher/common/nova_helper.py
@@ -422,8 +422,7 @@ class NovaHelper(object):
 
         return True
 
-    def live_migrate_instance(self, instance_id, dest_hostname,
-                              block_migration=False, retry=120):
+    def live_migrate_instance(self, instance_id, dest_hostname, retry=120):
         """This method does a live migration of a given instance
 
         This method uses the Nova built-in live_migrate()
@@ -436,7 +435,6 @@ class NovaHelper(object):
         :param dest_hostname: the name of the destination compute node, if
                               destination_node is None, nova scheduler choose
                               the destination host
-        :param block_migration:  No shared storage is required.
         """
         LOG.debug("Trying to live migrate instance %s " % (instance_id))
 
@@ -450,8 +448,9 @@ class NovaHelper(object):
             LOG.debug(
                 "Instance %s found on host '%s'." % (instance_id, host_name))
 
-            instance.live_migrate(host=dest_hostname,
-                                  block_migration=block_migration)
+            # From nova api version 2.25(Mitaka release), the default value of
+            # block_migration is None which is mapped to 'auto'.
+            instance.live_migrate(host=dest_hostname)
 
             instance = self.nova.servers.get(instance_id)
 
diff --git a/watcher/tests/applier/actions/test_migration.py b/watcher/tests/applier/actions/test_migration.py
index 7d85a0064..d7078320b 100644
--- a/watcher/tests/applier/actions/test_migration.py
+++ b/watcher/tests/applier/actions/test_migration.py
@@ -210,34 +210,6 @@ class TestMigration(base.TestCase):
                 dest_hostname="compute1-hostname"
             )
 
-    def test_live_migrate_non_shared_storage_instance(self):
-        self.m_helper.find_instance.return_value = self.INSTANCE_UUID
-
-        self.m_helper.live_migrate_instance.side_effect = [
-            nova_helper.nvexceptions.ClientException(400, "BadRequest"), True]
-
-        try:
-            self.action.execute()
-        except Exception as exc:
-            self.fail(exc)
-
-        self.m_helper.live_migrate_instance.assert_has_calls([
-            mock.call(instance_id=self.INSTANCE_UUID,
-                      dest_hostname="compute2-hostname"),
-            mock.call(instance_id=self.INSTANCE_UUID,
-                      dest_hostname="compute2-hostname",
-                      block_migration=True)
-        ])
-
-        expected = [mock.call.first(instance_id=self.INSTANCE_UUID,
-                                    dest_hostname="compute2-hostname"),
-                    mock.call.second(instance_id=self.INSTANCE_UUID,
-                                     dest_hostname="compute2-hostname",
-                                     block_migration=True)
-                    ]
-        self.m_helper.live_migrate_instance.mock_calls == expected
-        self.assertEqual(2, self.m_helper.live_migrate_instance.call_count)
-
     def test_abort_live_migrate(self):
         migration = mock.MagicMock()
         migration.id = "2"