Check for keystoneauth exceptions in mistral client plugin

We started to use keyston esession with mistal client plugin
since pike, but it seems the patch to translate keystoneauth
exceptions to mistal api exceptions did not get to
python-mistalclient==3.1.2.

Change-Id: I198cdbb8ee02623f2f5fb03a784135ce6f94a046
Closes-Bug: #1714679

heat/engine/clients/os/mistral.py

@@ -11,6 +11,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from keystoneauth1.exceptions import http as ka_exceptions
 from mistralclient.api import base as mistral_base
 from mistralclient.api import client as mistral_client
 
@@ -39,16 +40,28 @@ class MistralClientPlugin(client_plugin.ClientPlugin):
         return client
 
     def is_not_found(self, ex):
-        return (isinstance(ex, mistral_base.APIException) and
-                ex.error_code == 404)
+        # check for keystoneauth exceptions till requirements change
+        # to python-mistralclient > 3.1.2
+        ka_not_found = isinstance(ex, ka_exceptions.NotFound)
+        mistral_not_found = (isinstance(ex, mistral_base.APIException) and
+                             ex.error_code == 404)
+        return ka_not_found or mistral_not_found
 
     def is_over_limit(self, ex):
-        return (isinstance(ex, mistral_base.APIException) and
-                ex.error_code == 413)
+        # check for keystoneauth exceptions till requirements change
+        # to python-mistralclient > 3.1.2
+        ka_overlimit = isinstance(ex, ka_exceptions.RequestEntityTooLarge)
+        mistral_overlimit = (isinstance(ex, mistral_base.APIException) and
+                             ex.error_code == 413)
+        return ka_overlimit or mistral_overlimit
 
     def is_conflict(self, ex):
-        return (isinstance(ex, mistral_base.APIException) and
-                ex.error_code == 409)
+        # check for keystoneauth exceptions till requirements change
+        # to python-mistralclient > 3.1.2
+        ka_conflict = isinstance(ex, ka_exceptions.Conflict)
+        mistral_conflict = (isinstance(ex, mistral_base.APIException) and
+                            ex.error_code == 409)
+        return ka_conflict or mistral_conflict
 
     def get_workflow_by_identifier(self, workflow_identifier):
         try:

heat/tests/clients/test_clients.py

@@ -20,6 +20,7 @@ from heatclient import exc as heat_exc
 from keystoneauth1 import exceptions as keystone_exc
 from keystoneauth1.identity import generic
 from manilaclient import exceptions as manila_exc
+from mistralclient.api import base as mistral_base
 import mock
 from neutronclient.common import exceptions as neutron_exc
 from openstack import exceptions
@@ -792,6 +793,22 @@ class TestIsNotFound(common.HeatTestCase):
             plugin='manila',
             exception=lambda: manila_exc.Conflict(),
         )),
+        ('mistral_not_found1', dict(
+            is_not_found=True,
+            is_over_limit=False,
+            is_client_exception=False,
+            is_conflict=False,
+            plugin='mistral',
+            exception=lambda: mistral_base.APIException(404),
+        )),
+        ('mistral_not_found2', dict(
+            is_not_found=True,
+            is_over_limit=False,
+            is_client_exception=False,
+            is_conflict=False,
+            plugin='mistral',
+            exception=lambda: keystone_exc.NotFound(),
+        )),
     ]
 
     def test_is_not_found(self):