Implement schedule_prep_resize()

Implement schedule_prep_resize() in the distributed scheduler.  Adds
a request_spec argument to enable the current host of an instance
to be excluded for resizes.  Corrects bug 888236.

Change-Id: Ia52415e79639275a06bef59f1e13ca64bf7243ee

1 files changed, 50 insertions, 0 deletions

diff --git a/nova/tests/scheduler/test_chance_scheduler.py b/nova/tests/scheduler/test_chance_scheduler.py
new file mode 100644
index 000000000..8d4c73adb
--- /dev/null
+++ b/nova/tests/scheduler/test_chance_scheduler.py
@@ -0,0 +1,50 @@
+# Copyright 2011 OpenStack LLC.
+# All Rights Reserved.
+#
+#    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.
+"""
+Tests For Chance Scheduler.
+"""
+
+from nova import test
+from nova.scheduler import chance
+
+
+class ChanceSchedulerTestCase(test.TestCase):
+    """Test case for Chance Scheduler."""
+
+    def test_filter_hosts_avoid(self):
+        """Test to make sure _filter_hosts() filters original hosts if
+        avoid_original_host is True."""
+
+        sched = chance.ChanceScheduler()
+
+        hosts = ['host1', 'host2', 'host3']
+        request_spec = dict(original_host='host2',
+                            avoid_original_host=True)
+
+        filtered = sched._filter_hosts(request_spec, hosts)
+        self.assertEqual(filtered, ['host1', 'host3'])
+
+    def test_filter_hosts_no_avoid(self):
+        """Test to make sure _filter_hosts() does not filter original
+        hosts if avoid_original_host is False."""
+
+        sched = chance.ChanceScheduler()
+
+        hosts = ['host1', 'host2', 'host3']
+        request_spec = dict(original_host='host2',
+                            avoid_original_host=False)
+
+        filtered = sched._filter_hosts(request_spec, hosts)
+        self.assertEqual(filtered, hosts)