Adding informative message when deleting a used volume type

Currently when you try to delete a volume type (which is in use) Horizon
returns a generic message.

This patch includes in this message the text from the exception, resulting on
the following message:
'Error: Volume type '<vol_type>' is still in use.'

Change-Id: I9577127909dca70a4c45129bf5df7e11b6ab1c2f
Closes-bug: #1334523

horizon/exceptions.py

@@ -140,6 +140,11 @@ class Conflict(HorizonException):
     status_code = 409
 
 
+class BadRequest(HorizonException):
+    """Generic error to replace all "BadRequest"-type API errors."""
+    status_code = 400
+
+
 class RecoverableError(HorizonException):
     """Generic error to replace any "Recoverable"-type API errors."""
     status_code = 100  # HTTP status code "Continue"
@@ -224,7 +229,8 @@ UNAUTHORIZED = tuple(HORIZON_CONFIG['exceptions']['unauthorized'])
 UNAUTHORIZED += (NotAuthorized,)
 NOT_FOUND = tuple(HORIZON_CONFIG['exceptions']['not_found'])
 NOT_FOUND += (GetFileError,)
-RECOVERABLE = (AlreadyExists, Conflict, NotAvailable, ServiceCatalogException)
+RECOVERABLE = (AlreadyExists, Conflict, NotAvailable, ServiceCatalogException,
+               BadRequest)
 RECOVERABLE += tuple(HORIZON_CONFIG['exceptions']['recoverable'])
 
 

openstack_dashboard/api/cinder.py

@@ -26,7 +26,7 @@ from django.conf import settings
 from django.utils.translation import pgettext_lazy
 from django.utils.translation import ugettext_lazy as _
 
-from cinderclient.exceptions import ClientException  # noqa
+from cinderclient import exceptions as cinder_exception
 from cinderclient.v2.contrib import list_extensions as cinder_list_extensions
 
 from horizon import exceptions
@@ -497,7 +497,11 @@ def volume_type_default(request):
 
 
 def volume_type_delete(request, volume_type_id):
-    return cinderclient(request).volume_types.delete(volume_type_id)
+    try:
+        return cinderclient(request).volume_types.delete(volume_type_id)
+    except cinder_exception.BadRequest:
+        raise exceptions.BadRequest(_(
+            "This volume type is used by one or more volumes."))
 
 
 def volume_type_get(request, volume_type_id):

openstack_dashboard/dashboards/admin/volumes/volume_types/tables.py

@@ -10,6 +10,7 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+from django.core.urlresolvers import reverse
 from django.template import defaultfilters as filters
 from django.utils.translation import ugettext_lazy as _
 from django.utils.translation import ungettext_lazy
@@ -77,7 +78,11 @@ class DeleteVolumeType(tables.DeleteAction):
     policy_rules = (("volume", "volume_extension:types_manage"),)
 
     def delete(self, request, obj_id):
-        cinder.volume_type_delete(request, obj_id)
+        try:
+            cinder.volume_type_delete(request, obj_id)
+        except exceptions.BadRequest as e:
+            redirect_url = reverse("horizon:admin:volumes:index")
+            exceptions.handle(request, e, redirect=redirect_url)
 
 
 class CreateVolumeTypeEncryption(tables.LinkAction):

openstack_dashboard/dashboards/admin/volumes/volume_types/tests.py

@@ -14,6 +14,8 @@ from django.core.urlresolvers import reverse
 from django import http
 from mox3.mox import IsA  # noqa
 
+from horizon import exceptions
+
 from openstack_dashboard import api
 from openstack_dashboard.api import cinder
 from openstack_dashboard.api import keystone
@@ -93,6 +95,39 @@ class VolumeTypeTests(test.BaseAdminViewTests):
         self.assertNoFormErrors(res)
         self.assertRedirectsNoFollow(res, redirect)
 
+    @test.create_stubs({api.nova: ('server_list',),
+                        cinder: ('volume_list',
+                                 'volume_type_list_with_qos_associations',
+                                 'qos_spec_list',
+                                 'volume_type_delete',
+                                 'volume_encryption_type_list'),
+                        keystone: ('tenant_list',)})
+    def test_delete_volume_type_exception(self):
+        volume_type = self.volume_types.first()
+        formData = {'action': 'volume_types__delete__%s' % volume_type.id}
+        encryption_list = (self.cinder_volume_encryption_types.list()[0],
+                           self.cinder_volume_encryption_types.list()[1])
+
+        cinder.volume_type_list_with_qos_associations(
+            IsA(http.HttpRequest)).\
+            AndReturn(self.volume_types.list())
+        cinder.qos_spec_list(IsA(http.HttpRequest)).\
+            AndReturn(self.cinder_qos_specs.list())
+        cinder.volume_encryption_type_list(IsA(http.HttpRequest))\
+            .AndReturn(encryption_list)
+        cinder.volume_type_delete(IsA(http.HttpRequest),
+                                  str(volume_type.id))\
+            .AndRaise(exceptions.BadRequest())
+        self.mox.ReplayAll()
+
+        res = self.client.post(
+            reverse('horizon:admin:volumes:volumes_tab'),
+            formData)
+
+        redirect = reverse('horizon:admin:volumes:volumes_tab')
+        self.assertNoFormErrors(res)
+        self.assertRedirectsNoFollow(res, redirect)
+
     @test.create_stubs({cinder: ('volume_encryption_type_create',
                                  'volume_type_list',)})
     def test_create_volume_type_encryption(self):