Move CircularDependencyException to common

Moves the exception from inside the engine code
to the common code so that we can use it in the
API fault middleware.

Change-Id: I017b95153c358829501f6a5740918cdb005fb32f

heat/common/exception.py

@@ -568,3 +568,7 @@ class InvalidTemplateVersions(HeatException):
 
 class UnableToAutoAllocateNetwork(HeatException):
     msg_fmt = _('Unable to automatically allocate a network: %(message)s')
+
+
+class CircularDependencyException(HeatException):
+    msg_fmt = _("Circular Dependency Found: %(cycle)s")

heat/engine/dependencies.py

@@ -15,11 +15,6 @@ import collections
 import itertools
 
 from heat.common import exception
-from heat.common.i18n import _
-
-
-class CircularDependencyException(exception.HeatException):
-    msg_fmt = _("Circular Dependency Found: %(cycle)s")
 
 
 class Node(object):
@@ -163,7 +158,7 @@ class Graph(collections.defaultdict):
             else:
                 # There are nodes remaining, but none without
                 # dependencies: a cycle
-                raise CircularDependencyException(cycle=str(graph))
+                raise exception.CircularDependencyException(cycle=str(graph))
 
 
 class Dependencies(object):

heat/tests/engine/test_dependencies.py

@@ -11,7 +11,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-
+from heat.common import exception
 from heat.engine import dependencies
 from heat.tests import common
 
@@ -124,7 +124,7 @@ class dependenciesTest(common.HeatTestCase):
         d = dependencies.Dependencies([('first', 'second'),
                                        ('second', 'third'),
                                        ('third', 'first')])
-        self.assertRaises(dependencies.CircularDependencyException,
+        self.assertRaises(exception.CircularDependencyException,
                           list,
                           iter(d))
 
@@ -132,13 +132,13 @@ class dependenciesTest(common.HeatTestCase):
         d = dependencies.Dependencies([('first', 'second'),
                                        ('second', 'third'),
                                        ('third', 'first')])
-        self.assertRaises(dependencies.CircularDependencyException,
+        self.assertRaises(exception.CircularDependencyException,
                           list,
                           reversed(d))
 
     def test_self_ref(self):
         d = dependencies.Dependencies([('node', 'node')])
-        self.assertRaises(dependencies.CircularDependencyException,
+        self.assertRaises(exception.CircularDependencyException,
                           list,
                           iter(d))
 
@@ -147,7 +147,7 @@ class dependenciesTest(common.HeatTestCase):
                                        ('last', 'mid2'), ('mid1', 'e2'),
                                        ('mid1', 'mid3'), ('mid2', 'mid3'),
                                        ('mid3', 'e3'), ('e3', 'mid1')])
-        self.assertRaises(dependencies.CircularDependencyException,
+        self.assertRaises(exception.CircularDependencyException,
                           list,
                           iter(d))
 
@@ -156,7 +156,7 @@ class dependenciesTest(common.HeatTestCase):
                                        ('last', 'mid2'), ('mid1', 'e2'),
                                        ('mid1', 'mid3'), ('mid2', 'mid3'),
                                        ('mid3', 'e3'), ('e3', 'mid1')])
-        self.assertRaises(dependencies.CircularDependencyException,
+        self.assertRaises(exception.CircularDependencyException,
                           list,
                           reversed(d))
 

heat/tests/engine/test_scheduler.py

@@ -17,6 +17,7 @@ from unittest import mock
 
 import eventlet
 
+from heat.common import exception
 from heat.common import timeutils
 from heat.engine import dependencies
 from heat.engine import scheduler
@@ -259,7 +260,7 @@ class DependencyTaskGroupTest(common.HeatTestCase):
         d = dependencies.Dependencies([('first', 'second'),
                                        ('second', 'third'),
                                        ('third', 'first')])
-        self.assertRaises(dependencies.CircularDependencyException,
+        self.assertRaises(exception.CircularDependencyException,
                           scheduler.DependencyTaskGroup, d)
 
     def test_aggregate_exceptions_raises_all_at_the_end(self):

heat/tests/test_validate.py

@@ -21,7 +21,6 @@ from heat.common.i18n import _
 from heat.common import template_format
 from heat.common import urlfetch
 from heat.engine.clients.os import glance
-from heat.engine import dependencies
 from heat.engine import environment
 from heat.engine.hot import template as hot_tmpl
 from heat.engine import resources
@@ -2001,7 +2000,7 @@ parameter_groups:
         exc = self.assertRaises(dispatcher.ExpectedException,
                                 self.engine.validate_template,
                                 self.ctx, t, {})
-        self.assertEqual(dependencies.CircularDependencyException,
+        self.assertEqual(exception.CircularDependencyException,
                          exc.exc_info[0])
 
     def test_validate_hot_parameter_tags_older(self):