get rid of all mention of drivers ... it's filter only now

3 files changed, 75 insertions, 78 deletions

diff --git a/nova/exception.py b/nova/exception.py
index 56c20d111..dde39f29b 100644
--- a/nova/exception.py
+++ b/nova/exception.py
@@ -465,9 +465,8 @@ class ZoneNotFound(NotFound):
     message = _("Zone %(zone_id)s could not be found.")
 
 
-class SchedulerHostFilterDriverNotFound(NotFound):
-    message = _("Scheduler Host Filter Driver %(driver_name)s could"
-                " not be found.")
+class SchedulerHostFilterNotFound(NotFound):
+    message = _("Scheduler Host Filter %(filter_name)s could not be found.")
 
 
 class InstanceMetadataNotFound(NotFound):
diff --git a/nova/scheduler/host_filter.py b/nova/scheduler/host_filter.py
index 92ec827d3..d9771754a 100644
--- a/nova/scheduler/host_filter.py
+++ b/nova/scheduler/host_filter.py
@@ -14,8 +14,8 @@
 #    under the License.
 
 """
-Host Filter is a driver mechanism for requesting instance resources.
-Three drivers are included: AllHosts, Flavor & JSON. AllHosts just
+Host Filter is a mechanism for requesting instance resources.
+Three filters are included: AllHosts, Flavor & JSON. AllHosts just
 returns the full, unfiltered list of hosts. Flavor is a hard coded
 matching mechanism based on flavor criteria and JSON is an ad-hoc
 filter grammar.
@@ -47,13 +47,13 @@ from nova.scheduler import zone_aware_scheduler
 LOG = logging.getLogger('nova.scheduler.host_filter')
 
 FLAGS = flags.FLAGS
-flags.DEFINE_string('default_host_filter_driver',
+flags.DEFINE_string('default_host_filter',
                     'nova.scheduler.host_filter.AllHostsFilter',
-                    'Which driver to use for filtering hosts.')
+                    'Which filter to use for filtering hosts.')
 
 
 class HostFilter(object):
-    """Base class for host filter drivers."""
+    """Base class for host filters."""
 
     def instance_type_to_filter(self, instance_type):
         """Convert instance_type into a filter for most common use-case."""
@@ -64,12 +64,12 @@ class HostFilter(object):
         raise NotImplementedError()
 
     def _full_name(self):
-        """module.classname of the filter driver"""
+        """module.classname of the filter."""
         return "%s.%s" % (self.__module__, self.__class__.__name__)
 
 
 class AllHostsFilter(HostFilter):
-    """NOP host filter driver. Returns all hosts in ZoneManager.
+    """NOP host filter. Returns all hosts in ZoneManager.
     This essentially does what the old Scheduler+Chance used
     to give us."""
 
@@ -85,7 +85,7 @@ class AllHostsFilter(HostFilter):
 
 
 class InstanceTypeFilter(HostFilter):
-    """HostFilter driver hard-coded to work with InstanceType records."""
+    """HostFilter hard-coded to work with InstanceType records."""
 
     def instance_type_to_filter(self, instance_type):
         """Use instance_type to filter hosts."""
@@ -133,7 +133,7 @@ class InstanceTypeFilter(HostFilter):
 
 
 class JsonFilter(HostFilter):
-    """Host Filter driver to allow simple JSON-based grammar for
+    """Host Filter to allow simple JSON-based grammar for
        selecting hosts."""
 
     def _equals(self, args):
@@ -273,43 +273,44 @@ class JsonFilter(HostFilter):
         return hosts
 
 
-DRIVERS = [AllHostsFilter, InstanceTypeFilter, JsonFilter]
+FILTERS = [AllHostsFilter, InstanceTypeFilter, JsonFilter]
 
 
-def choose_driver(driver_name=None):
-    """Since the caller may specify which driver to use we need
+def choose_host_filter(filter_name=None):
+    """Since the caller may specify which filter to use we need
        to have an authoritative list of what is permissible. This
-       function checks the driver name against a predefined set
-       of acceptable drivers."""
+       function checks the filter name against a predefined set
+       of acceptable filters."""
 
-    if not driver_name:
-        driver_name = FLAGS.default_host_filter_driver
-    for driver in DRIVERS:
-        if "%s.%s" % (driver.__module__, driver.__name__) == driver_name:
-            return driver()
-    raise exception.SchedulerHostFilterDriverNotFound(driver_name=driver_name)
+    if not filter_name:
+        filter_name = FLAGS.default_host_filter
+    for filter_class in FILTERS:
+        if "%s.%s" % (filter_class.__module__, filter_class.__name__) == \
+                filter_name:
+            return filter_class()
+    raise exception.SchedulerHostFilterNotFound(filter_name=filter_name)
 
 
 class HostFilterScheduler(zone_aware_scheduler.ZoneAwareScheduler):
-    """The HostFilterScheduler uses the HostFilter drivers to filter
-    hosts for weighing. The particular driver used may be passed in
+    """The HostFilterScheduler uses the HostFilter to filter
+    hosts for weighing. The particular filter used may be passed in
     as an argument or the default will be used.
 
-    request_spec = {'filter_driver': <Filter Driver name>,
+    request_spec = {'filter_name': <Filter name>,
                     'instance_type': <InstanceType dict>}
     """
 
     def filter_hosts(self, num, request_spec):
         """Filter the full host list (from the ZoneManager)"""
-        driver_name = request_spec.get('filter_driver', None)
-        driver = choose_driver(driver_name)
+        filter_name = request_spec.get('filter_name', None)
+        host_filter = choose_host_filter(filter_name)
 
         # TODO(sandy): We're only using InstanceType-based specs
         # currently. Later we'll need to snoop for more detailed
         # host filter requests.
         instance_type = request_spec['instance_type']
-        name, query = driver.instance_type_to_filter(instance_type)
-        return driver.filter_hosts(self.zone_manager, query)
+        name, query = host_filter.instance_type_to_filter(instance_type)
+        return host_filter.filter_hosts(self.zone_manager, query)
 
     def weigh_hosts(self, num, request_spec, hosts):
         """Derived classes must override this method and return
diff --git a/nova/tests/test_host_filter.py b/nova/tests/test_host_filter.py
index dd2325cc6..07817cc5a 100644
--- a/nova/tests/test_host_filter.py
+++ b/nova/tests/test_host_filter.py
@@ -13,7 +13,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 """
-Tests For Scheduler Host Filter Drivers.
+Tests For Scheduler Host Filters.
 """
 
 import json
@@ -31,7 +31,7 @@ class FakeZoneManager:
 
 
 class HostFilterTestCase(test.TestCase):
-    """Test case for host filter drivers."""
+    """Test case for host filters."""
 
     def _host_caps(self, multiplier):
         # Returns host capabilities in the following way:
@@ -57,8 +57,8 @@ class HostFilterTestCase(test.TestCase):
                 'host_name-label': 'xs-%s' % multiplier}
 
     def setUp(self):
-        self.old_flag = FLAGS.default_host_filter_driver
-        FLAGS.default_host_filter_driver = \
+        self.old_flag = FLAGS.default_host_filter
+        FLAGS.default_host_filter = \
                             'nova.scheduler.host_filter.AllHostsFilter'
         self.instance_type = dict(name='tiny',
                 memory_mb=50,
@@ -76,52 +76,52 @@ class HostFilterTestCase(test.TestCase):
         self.zone_manager.service_states = states
 
     def tearDown(self):
-        FLAGS.default_host_filter_driver = self.old_flag
+        FLAGS.default_host_filter = self.old_flag
 
-    def test_choose_driver(self):
-        # Test default driver ...
-        driver = host_filter.choose_driver()
-        self.assertEquals(driver._full_name(),
+    def test_choose_filter(self):
+        # Test default filter ...
+        hf = host_filter.choose_host_filter()
+        self.assertEquals(hf._full_name(),
                         'nova.scheduler.host_filter.AllHostsFilter')
-        # Test valid driver ...
-        driver = host_filter.choose_driver(
+        # Test valid filter ...
+        hf = host_filter.choose_host_filter(
                         'nova.scheduler.host_filter.InstanceTypeFilter')
-        self.assertEquals(driver._full_name(),
+        self.assertEquals(hf._full_name(),
                         'nova.scheduler.host_filter.InstanceTypeFilter')
-        # Test invalid driver ...
+        # Test invalid filter ...
         try:
-            host_filter.choose_driver('does not exist')
-            self.fail("Should not find driver")
-        except exception.SchedulerHostFilterDriverNotFound:
+            host_filter.choose_host_filter('does not exist')
+            self.fail("Should not find host filter.")
+        except exception.SchedulerHostFilterNotFound:
             pass
 
-    def test_all_host_driver(self):
-        driver = host_filter.AllHostsFilter()
-        cooked = driver.instance_type_to_filter(self.instance_type)
-        hosts = driver.filter_hosts(self.zone_manager, cooked)
+    def test_all_host_filter(self):
+        hf = host_filter.AllHostsFilter()
+        cooked = hf.instance_type_to_filter(self.instance_type)
+        hosts = hf.filter_hosts(self.zone_manager, cooked)
         self.assertEquals(10, len(hosts))
         for host, capabilities in hosts:
             self.assertTrue(host.startswith('host'))
 
-    def test_instance_type_driver(self):
-        driver = host_filter.InstanceTypeFilter()
+    def test_instance_type_filter(self):
+        hf = host_filter.InstanceTypeFilter()
         # filter all hosts that can support 50 ram and 500 disk
-        name, cooked = driver.instance_type_to_filter(self.instance_type)
+        name, cooked = hf.instance_type_to_filter(self.instance_type)
         self.assertEquals('nova.scheduler.host_filter.InstanceTypeFilter',
                           name)
-        hosts = driver.filter_hosts(self.zone_manager, cooked)
+        hosts = hf.filter_hosts(self.zone_manager, cooked)
         self.assertEquals(6, len(hosts))
         just_hosts = [host for host, caps in hosts]
         just_hosts.sort()
         self.assertEquals('host05', just_hosts[0])
         self.assertEquals('host10', just_hosts[5])
 
-    def test_json_driver(self):
-        driver = host_filter.JsonFilter()
+    def test_json_filter(self):
+        hf = host_filter.JsonFilter()
         # filter all hosts that can support 50 ram and 500 disk
-        name, cooked = driver.instance_type_to_filter(self.instance_type)
+        name, cooked = hf.instance_type_to_filter(self.instance_type)
         self.assertEquals('nova.scheduler.host_filter.JsonFilter', name)
-        hosts = driver.filter_hosts(self.zone_manager, cooked)
+        hosts = hf.filter_hosts(self.zone_manager, cooked)
         self.assertEquals(6, len(hosts))
         just_hosts = [host for host, caps in hosts]
         just_hosts.sort()
@@ -141,7 +141,7 @@ class HostFilterTestCase(test.TestCase):
                    ]
               ]
         cooked = json.dumps(raw)
-        hosts = driver.filter_hosts(self.zone_manager, cooked)
+        hosts = hf.filter_hosts(self.zone_manager, cooked)
 
         self.assertEquals(5, len(hosts))
         just_hosts = [host for host, caps in hosts]
@@ -153,7 +153,7 @@ class HostFilterTestCase(test.TestCase):
                   ['=', '$compute.host_memory_free', 30],
               ]
         cooked = json.dumps(raw)
-        hosts = driver.filter_hosts(self.zone_manager, cooked)
+        hosts = hf.filter_hosts(self.zone_manager, cooked)
 
         self.assertEquals(9, len(hosts))
         just_hosts = [host for host, caps in hosts]
@@ -163,7 +163,7 @@ class HostFilterTestCase(test.TestCase):
 
         raw = ['in', '$compute.host_memory_free', 20, 40, 60, 80, 100]
         cooked = json.dumps(raw)
-        hosts = driver.filter_hosts(self.zone_manager, cooked)
+        hosts = hf.filter_hosts(self.zone_manager, cooked)
 
         self.assertEquals(5, len(hosts))
         just_hosts = [host for host, caps in hosts]
@@ -175,35 +175,32 @@ class HostFilterTestCase(test.TestCase):
         raw = ['unknown command', ]
         cooked = json.dumps(raw)
         try:
-            driver.filter_hosts(self.zone_manager, cooked)
+            hf.filter_hosts(self.zone_manager, cooked)
             self.fail("Should give KeyError")
         except KeyError, e:
             pass
 
-        self.assertTrue(driver.filter_hosts(self.zone_manager, json.dumps([])))
-        self.assertTrue(driver.filter_hosts(self.zone_manager, json.dumps({})))
-        self.assertTrue(driver.filter_hosts(self.zone_manager, json.dumps(
+        self.assertTrue(hf.filter_hosts(self.zone_manager, json.dumps([])))
+        self.assertTrue(hf.filter_hosts(self.zone_manager, json.dumps({})))
+        self.assertTrue(hf.filter_hosts(self.zone_manager, json.dumps(
                 ['not', True, False, True, False]
             )))
 
         try:
-            driver.filter_hosts(self.zone_manager, json.dumps(
+            hf.filter_hosts(self.zone_manager, json.dumps(
                 'not', True, False, True, False
             ))
             self.fail("Should give KeyError")
         except KeyError, e:
             pass
 
-        self.assertFalse(driver.filter_hosts(self.zone_manager, json.dumps(
-                ['=', '$foo', 100]
-            )))
-        self.assertFalse(driver.filter_hosts(self.zone_manager, json.dumps(
-                ['=', '$.....', 100]
-            )))
-        self.assertFalse(driver.filter_hosts(self.zone_manager, json.dumps(
-            ['>', ['and', ['or', ['not', ['<', ['>=', ['<=', ['in', ]]]]]]]]
-        )))
+        self.assertFalse(hf.filter_hosts(self.zone_manager,
+                json.dumps(['=', '$foo', 100])))
+        self.assertFalse(hf.filter_hosts(self.zone_manager,
+                json.dumps(['=', '$.....', 100])))
+        self.assertFalse(hf.filter_hosts(self.zone_manager,
+                json.dumps(
+            ['>', ['and', ['or', ['not', ['<', ['>=', ['<=', ['in', ]]]]]]]])))
 
-        self.assertFalse(driver.filter_hosts(self.zone_manager, json.dumps(
-                ['=', {}, ['>', '$missing....foo']]
-            )))
+        self.assertFalse(hf.filter_hosts(self.zone_manager,
+                json.dumps(['=', {}, ['>', '$missing....foo']])))