Move network constraint to neutron plugin

This allows exception imports to be encapsulated inside the neutron
plugin, and plugins are likely the most appropriate place for
custom constraints to live.

Change-Id: I5766edb305b7cfffdcd8943fb6edce7f3e9ff26d

heat/engine/clients/os/neutron.py

@@ -11,9 +11,12 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from neutronclient.common import exceptions
+from neutronclient.neutron import v2_0 as neutronV20
 from neutronclient.v2_0 import client as nc
 
 from heat.engine.clients import client_plugin
+from heat.engine import constraints
 
 
 class NeutronClientPlugin(client_plugin.ClientPlugin):
@@ -35,3 +38,13 @@ class NeutronClientPlugin(client_plugin.ClientPlugin):
         }
 
         return nc.Client(**args)
+
+
+class NetworkConstraint(constraints.BaseCustomConstraint):
+
+    expected_exceptions = (exceptions.NeutronClientException,)
+
+    def validate_with_client(self, client, value):
+        neutron_client = client.client('neutron')
+        neutronV20.find_resourceid_by_name_or_id(
+            neutron_client, 'network', value)

heat/engine/resources/neutron/net.py

@@ -12,12 +12,10 @@
 #    under the License.
 
 from heat.engine import attributes
-from heat.engine import constraints
 from heat.engine import properties
 from heat.engine.resources.neutron import neutron
 
 import neutronclient.common.exceptions as neutron_exp
-from neutronclient.neutron import v2_0 as neutronV20
 
 
 class Net(neutron.NeutronResource):
@@ -182,16 +180,6 @@ class Net(neutron.NeutronResource):
                     raise ex
 
 
-class NetworkConstraint(constraints.BaseCustomConstraint):
-
-    expected_exceptions = (neutron_exp.NeutronClientException,)
-
-    def validate_with_client(self, client, value):
-        neutron_client = client.client('neutron')
-        neutronV20.find_resourceid_by_name_or_id(
-            neutron_client, 'network', value)
-
-
 def resource_mapping():
     return {
         'OS::Neutron::Net': Net,

heat/tests/test_neutron.py

@@ -2397,16 +2397,17 @@ class NetworkConstraintTest(HeatTestCase):
         nc = self.m.CreateMockAnything()
         self.m.StubOutWithMock(neutron.NeutronClientPlugin, '_create')
         neutron.NeutronClientPlugin._create().AndReturn(nc)
-        self.m.StubOutWithMock(net.neutronV20, 'find_resourceid_by_name_or_id')
+        self.m.StubOutWithMock(neutron.neutronV20,
-        net.neutronV20.find_resourceid_by_name_or_id(
+                               'find_resourceid_by_name_or_id')
+        neutron.neutronV20.find_resourceid_by_name_or_id(
             nc, 'network', 'foo'
         ).AndReturn('foo')
-        net.neutronV20.find_resourceid_by_name_or_id(
+        neutron.neutronV20.find_resourceid_by_name_or_id(
             nc, 'network', 'bar'
         ).AndRaise(qe.NeutronClientException(status_code=404))
         self.m.ReplayAll()
 
-        constraint = net.NetworkConstraint()
+        constraint = neutron.NetworkConstraint()
         ctx = utils.dummy_context()
         self.assertTrue(constraint.validate("foo", ctx))
         self.assertFalse(constraint.validate("bar", ctx))

setup.cfg

@@ -50,7 +50,7 @@ heat.clients =
 
 heat.constraints =
     nova.flavor = heat.engine.resources.server:FlavorConstraint
-    neutron.network = heat.engine.resources.neutron.net:NetworkConstraint
+    neutron.network = heat.engine.clients.os.neutron:NetworkConstraint
     glance.image = heat.engine.resources.image:ImageConstraint
     iso_8601 = heat.engine.resources.iso_8601:ISO8601Constraint
     nova.keypair = heat.engine.resources.nova_keypair:KeypairConstraint