Merge "Add IgnoreAttemptedHostsFilter to oslo"

openstack/common/scheduler/filters/ignore_attempted_hosts_filter.py

@@ -0,0 +1,50 @@
+# Copyright (c) 2011 OpenStack Foundation.
+# 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.
+
+from openstack.common.gettextutils import _
+from openstack.common import log as logging
+from openstack.common.scheduler import filters
+
+LOG = logging.getLogger(__name__)
+
+
+class IgnoreAttemptedHostsFilter(filters.BaseHostFilter):
+    """Filter out previously attempted hosts
+
+    A host passes this filter if it has not already been attempted for
+    scheduling. The scheduler needs to add previously attempted hosts
+    to the 'attempted' key of filter_properties in order for this to work
+    correctly.
+    """
+
+    def host_passes(self, host_state, filter_properties):
+        """Skip nodes that have already been attempted."""
+        attempted = filter_properties.get('attempted', None)
+        if not attempted:
+            # Re-scheduling is disabled
+            LOG.debug(_("Re-scheduling is disabled"))
+            return True
+
+        hosts = attempted.get('hosts', [])
+        host = host_state.host
+
+        passes = host not in hosts
+        pass_msg = "passes" if passes else "fails"
+
+        LOG.debug(_("Host %(host)s %(pass_msg)s.  Previously tried hosts: "
+                    "%(hosts)s") % {'host': host,
+                                    'pass_msg': pass_msg,
+                                    'hosts': hosts})
+        return passes

setup.cfg

@@ -37,6 +37,7 @@ openstack.common.scheduler.filters =
     AvailabilityZoneFilter = openstack.common.scheduler.filters.availability_zone_filter:AvailabilityZoneFilter
     CapabilitiesFilter = openstack.common.scheduler.filters.capabilities_filter:CapabilitiesFilter
     JsonFilter = openstack.common.scheduler.filters.json_filter:JsonFilter
+    IgnoreAttemptedHostsFilter = openstack.common.scheduler.filters.ignore_attempted_hosts_filter:IgnoreAttemptedHostsFilter
 
 openstack.common.tests.fakes.weights =
     FakeWeigher1 = tests.unit.fakes:FakeWeigher1

tests/unit/scheduler/fake_hosts.py

@@ -47,5 +47,6 @@ class FakeHostManager(object):
 
 class FakeHostState(object):
     def __init__(self, host, attribute_dict):
+        self.host = host
         for (key, val) in six.iteritems(attribute_dict):
             setattr(self, key, val)

tests/unit/scheduler/test_host_filters.py

@@ -270,6 +270,7 @@ class HostFiltersTestCase(test.BaseTestCase):
         self.assertTrue('JsonFilter' in self.class_map)
         self.assertTrue('CapabilitiesFilter' in self.class_map)
         self.assertTrue('AvailabilityZoneFilter' in self.class_map)
+        self.assertTrue('IgnoreAttemptedHostsFilter' in self.class_map)
 
     def _do_test_type_filter_extra_specs(self, ecaps, especs, passes):
         filt_cls = self.class_map['CapabilitiesFilter']()
@@ -676,3 +677,26 @@ class HostFiltersTestCase(test.BaseTestCase):
         host = fakes.FakeHostState('host1',
                                    {'service': service})
         self.assertTrue(filt_cls.host_passes(host, request))
+
+    def test_ignore_attempted_hosts_filter_disabled(self):
+        # Test case where re-scheduling is disabled.
+        filt_cls = self.class_map['IgnoreAttemptedHostsFilter']()
+        host = fakes.FakeHostState('host1', {})
+        filter_properties = {}
+        self.assertTrue(filt_cls.host_passes(host, filter_properties))
+
+    def test_ignore_attempted_hosts_filter_pass(self):
+        # Node not previously tried.
+        filt_cls = self.class_map['IgnoreAttemptedHostsFilter']()
+        host = fakes.FakeHostState('host1', {})
+        attempted = dict(num_attempts=2, hosts=['host2'])
+        filter_properties = dict(attempted=attempted)
+        self.assertTrue(filt_cls.host_passes(host, filter_properties))
+
+    def test_ignore_attempted_hosts_filter_fail(self):
+        # Node was already tried.
+        filt_cls = self.class_map['IgnoreAttemptedHostsFilter']()
+        host = fakes.FakeHostState('host1', {})
+        attempted = dict(num_attempts=2, hosts=['host1'])
+        filter_properties = dict(attempted=attempted)
+        self.assertFalse(filt_cls.host_passes(host, filter_properties))