allows a mgmt user to migrate an instance to a specific host

a mgmt user and use the instance migrate api and specify a host that
they would like the instance to move to.
Fixing migration fake mode.

implements blueprint migration-force-to-host
https://blueprints.launchpad.net/reddwarf/+spec/migration-force-to-host

Change-Id: I1fd7b2f5ae5328de642ec1ad6ee4d62c5a29168f

trove/extensions/mgmt/instances/service.py

@@ -128,7 +128,9 @@ class MgmtInstanceController(InstanceController):
 
     def _action_migrate(self, context, instance, body):
         LOG.debug("Migrating instance %s." % instance.id)
-        instance.migrate()
+        LOG.debug("body['migrate']= %s" % body['migrate'])
+        host = body['migrate'].get('host', None)
+        instance.migrate(host)
         return wsgi.Result(None, 202)
 
     def _action_reset_task_status(self, context, instance, body):

trove/instance/models.py

@@ -554,11 +554,11 @@ class Instance(BuiltInstance):
         self.update_db(task_status=InstanceTasks.REBOOTING)
         task_api.API(self.context).restart(self.id)
 
-    def migrate(self):
+    def migrate(self, host=None):
         self.validate_can_perform_action()
-        LOG.info("Migrating instance %s..." % self.id)
+        LOG.info("Migrating instance id = %s, to host = %s" % (self.id, host))
         self.update_db(task_status=InstanceTasks.MIGRATING)
-        task_api.API(self.context).migrate(self.id)
+        task_api.API(self.context).migrate(self.id, host)
 
     def reset_task_status(self):
         LOG.info("Settting task status to NONE on instance %s..." % self.id)

trove/taskmanager/api.py

@@ -88,9 +88,9 @@ class API(ManagerAPI):
         LOG.debug("Making async call to restart instance: %s" % instance_id)
         self._cast("restart", instance_id=instance_id)
 
-    def migrate(self, instance_id):
+    def migrate(self, instance_id, host):
         LOG.debug("Making async call to migrate instance: %s" % instance_id)
-        self._cast("migrate", instance_id=instance_id)
+        self._cast("migrate", instance_id=instance_id, host=host)
 
     def delete_instance(self, instance_id):
         LOG.debug("Making async call to delete instance: %s" % instance_id)

trove/taskmanager/manager.py

@@ -59,9 +59,9 @@ class Manager(periodic_task.PeriodicTasks):
         instance_tasks = models.BuiltInstanceTasks.load(context, instance_id)
         instance_tasks.restart()
 
-    def migrate(self, context, instance_id):
+    def migrate(self, context, instance_id, host):
         instance_tasks = models.BuiltInstanceTasks.load(context, instance_id)
-        instance_tasks.migrate()
+        instance_tasks.migrate(host)
 
     def delete_instance(self, context, instance_id):
         try:

trove/taskmanager/models.py

@@ -487,8 +487,9 @@ class BuiltInstanceTasks(BuiltInstance, NotifyMixin, ConfigurationMixin):
         action = ResizeAction(self, old_flavor, new_flavor)
         action.execute()
 
-    def migrate(self):
-        action = MigrateAction(self)
+    def migrate(self, host):
+        LOG.debug("Calling migrate with host(%s)..." % host)
+        action = MigrateAction(self, host)
         action.execute()
 
     def create_backup(self, backup_id):
@@ -788,13 +789,18 @@ class ResizeAction(ResizeActionBase):
 
 
 class MigrateAction(ResizeActionBase):
+    def __init__(self, instance, host=None):
+        self.instance = instance
+        self.host = host
+
     def _assert_nova_action_was_successful(self):
         LOG.debug("Currently no assertions for a Migrate Action")
 
     def _initiate_nova_action(self):
         LOG.debug("Migrating instance %s without flavor change ..."
                   % self.instance.id)
-        self.instance.server.migrate()
+        LOG.debug("Forcing migration to host(%s)" % self.host)
+        self.instance.server.migrate(force_host=self.host)
 
     def _record_action_success(self):
         LOG.debug("Successfully finished Migration to %s: %s" %

trove/tests/api/instances_resize.py

@@ -227,8 +227,9 @@ class MigrateTests(ResizeTestBase):
         self.guest.restart()
 
     def test_successful_migrate(self):
+        self.mock.StubOutWithMock(self.instance.server, 'migrate')
         self._stop_db()
-        self.server.migrate()
+        self.server.migrate(force_host=None)
         self._server_changes_to("VERIFY_RESIZE", NEW_FLAVOR_ID)
         self.instance._set_service_status_to_paused()
         self.instance.service_status = ServiceStatuses.RUNNING

trove/tests/fakes/nova.py

@@ -174,10 +174,10 @@ class FakeServer(object):
         return [{"href": url, "rel": link_type}
                 for link_type in ['self', 'bookmark']]
 
-    def migrate(self):
-        self.resize(None)
+    def migrate(self, force_host=None):
+        self.resize(None, force_host)
 
-    def resize(self, new_flavor_id=None):
+    def resize(self, new_flavor_id=None, force_host=None):
         self._current_status = "RESIZE"
         if self.name.endswith("_RESIZE_TIMEOUT"):
             raise PollTimeOut()
@@ -191,7 +191,11 @@ class FakeServer(object):
 
         def change_host():
             self.old_host = self.host
-            self.host = [host for host in FAKE_HOSTS if host != self.host][0]
+            if not force_host:
+                self.host = [host for host in FAKE_HOSTS
+                             if host != self.host][0]
+            else:
+                self.host = force_host
 
         def set_flavor():
             if self.name.endswith("_RESIZE_ERROR"):