Merge lp:~devcamcar/django-nova/maintenance_mode into lp:django-nova

[Devin Carlen]

Added awareness of nova's maintenance mode to django-nova

[Devin Carlen (devcamcar)]

review: Approve

=== modified file 'src/django_nova/exceptions.py'
--- src/django_nova/exceptions.py	2011-01-12 20:02:06 +0000
+++ src/django_nova/exceptions.py	2011-01-15 09:31:13 +0000
@@ -15,14 +15,20 @@
 #    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 #    License for the specific language governing permissions and limitations
 #    under the License.
+
 """
 Better wrappers for errors from Nova's admin api.
 """
 
 import boto.exception
+from django.shortcuts import redirect
+from django.utils.http import urlquote
 
 
 class NovaResponseError(Exception):
+    """
+    Consumes a BotoServerError and gives more meaningful errors.
+    """
     def __init__(self, ec2error):
         self.code = ec2error.reason
         if ec2error.reason == 'Unauthorized':
@@ -36,15 +42,37 @@
         return self.message
 
 
-def handle_nova_error(fn):
-    def decorator(view_func):
-        def wrapper(*args, **kwargs):
-            try:
-                return view_func(*args, **kwargs)
-            except boto.exception.EC2ResponseError, e:
-                raise NovaResponseError(e)
-        return wrapper
-    return decorator(fn)
-
-
+class NovaUnavailableError(Exception):
+    """
+    Used when Nova returns a 503 Service Unavailable status.
+    """
+    pass
+
+
+def wrap_nova_error(func):
+    """
+    Used to decorate a function that interacts with boto. It will catch
+    and convert boto server errors and reraise as a more specific nova error.
+    """
+    def decorator(*args, **kwargs):
+        try:
+            return func(*args, **kwargs)
+        except boto.exception.BotoServerError, e:
+            if e.status == 503:
+                raise NovaUnavailableError(e)
+            raise NovaResponseError(e)
+    return decorator
+
+
+def handle_nova_error(func):
+    """
+    Decorator for handling nova errors in a generalized way.
+    """
+    def decorator(*args, **kwargs):
+        try:
+            return func(*args, **kwargs)
+        except NovaUnavailableError:
+            return redirect('nova_unavailable')
+    return decorator
+    
 

=== modified file 'src/django_nova/forms.py'
--- src/django_nova/forms.py	2011-01-12 20:02:06 +0000
+++ src/django_nova/forms.py	2011-01-15 09:31:13 +0000
@@ -15,6 +15,7 @@
 #    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 #    License for the specific language governing permissions and limitations
 #    under the License.
+
 """
 Forms used by various views.
 """
@@ -24,6 +25,7 @@
 from django import forms
 from django.contrib.auth import models as auth_models
 from django_nova.connection import get_nova_admin_connection
+from django_nova.exceptions import wrap_nova_error
 
 
 # TODO: Store this in settings.
@@ -32,6 +34,7 @@
 alphanumeric_re = re.compile(r'^\w+$')
 
 
+@wrap_nova_error
 def get_instance_type_choices():
     """
     Returns list of instance types from nova admin api
@@ -75,11 +78,13 @@
         ('udp', 'udp'),
     )
 
+
 class ProjectFormBase(forms.Form):
     def __init__(self, project, *args, **kwargs):
         self.project = project
         super(ProjectFormBase, self).__init__(*args, **kwargs)
 
+
 class LaunchInstanceForm(forms.Form):
     # nickname = forms.CharField()
     # description = forms.CharField()
@@ -96,6 +101,7 @@
         self.fields['key_name'].choices = get_key_pair_choices(project)
         self.fields['size'].choices = get_instance_type_choices()
 
+
 class UpdateInstanceForm(forms.Form):
     nickname = forms.CharField(required=False, label="Name")
     description = forms.CharField(required=False, widget=forms.Textarea, max_length=70)
@@ -105,6 +111,7 @@
         self.fields['nickname'].initial = instance.displayName
         self.fields['description'].initial = instance.displayDescription
 
+
 class UpdateImageForm(forms.Form):
     nickname = forms.CharField(required=False, label="Name")
     description = forms.CharField(required=False, widget=forms.Textarea, max_length=70)
@@ -126,6 +133,7 @@
 
         return name
 
+
 class CreateSecurityGroupForm(ProjectFormBase):
     name = forms.RegexField(regex=alphanumeric_re)
     description = forms.CharField()
@@ -138,16 +146,19 @@
 
         return name
 
+
 class AuthorizeSecurityGroupRuleForm(forms.Form):
     protocol = forms.ChoiceField(choices=get_protocols())
     from_port = forms.IntegerField(min_value=1, max_value=65535)
     to_port = forms.IntegerField(min_value=1, max_value=65535)
 
+
 class CreateVolumeForm(forms.Form):
     size = forms.IntegerField(label='Size (in GB)', min_value=1, max_value=MAX_VOLUME_SIZE)
     nickname = forms.CharField()
     description = forms.CharField()
 
+
 class AttachVolumeForm(ProjectFormBase):
     volume = forms.ChoiceField()
     instance = forms.ChoiceField()
@@ -158,6 +169,7 @@
         self.fields['volume'].choices = get_available_volume_choices(project)
         self.fields['instance'].choices = get_instance_choices(project)
 
+
 class ProjectForm(forms.Form):
     projectname = forms.CharField(label="Project Name", max_length=20)
     description = forms.CharField(label="Description",
@@ -165,38 +177,50 @@
     manager = forms.ModelChoiceField(queryset=auth_models.User.objects.all(),
                                      label="Project Manager")
 
-def get_roles():
-    return (
-        ('netadmin', 'Netadmin'),
-        ('sysadmin', 'Sysadmin'),
-        ('developer', 'Developer'),
-    )
+@wrap_nova_error
+def get_roles(project_roles=True):
+    nova = get_nova_admin_connection()
+    roles = nova.get_roles(project_roles=project_roles)
+    return [(role.role, role.role) for role in roles]
+
+
+@wrap_nova_error
+def get_members(project):
+    nova = get_nova_admin_connection()
+    members = nova.get_project_members(project)
+    return [str(user.memberId) for user in members]
+
 
 class GlobalRolesForm(forms.Form):
-    nova = get_nova_admin_connection()
-    roles = [(role.role, role.role) for role in nova.get_roles(project_roles=False)]
-
-    role = forms.MultipleChoiceField(choices=roles, label='Roles', required=False)
+    role = forms.MultipleChoiceField(label='Roles', required=False)
+
+    def __init__(self, *args, **kwargs):
+        super(GlobalRolesForm, self).__init__(*args, **kwargs)
+        self.fields['role'].choices = get_roles(project_roles=False)
+
 
 class ProjectUserForm(forms.Form):
-    nova = get_nova_admin_connection()
-    roles = [(role.role, role.role) for role in nova.get_roles(project_roles=True)]
-
-    role = forms.MultipleChoiceField(choices=roles, label='Roles', required=False)
+    role = forms.MultipleChoiceField(label='Roles', required=False)
+
+    def __init__(self, *args, **kwargs):
+        super(ProjectUserForm, self).__init__(*args, **kwargs)
+        self.fields['role'].choices = get_roles(project_roles=False)
+
 
 class AddProjectUserForm(forms.Form):
-    username = forms.ModelChoiceField(queryset='', label='Username', empty_label='Select a Username')
-    role = forms.MultipleChoiceField(choices=get_roles(), label='Roles')
+    username = forms.ModelChoiceField(queryset='',
+                                      label='Username',
+                                      empty_label='Select a Username')
+    role = forms.MultipleChoiceField(label='Roles')
 
     def __init__(self, *args, **kwargs):
         project = kwargs.pop('project')
         super(AddProjectUserForm, self).__init__(*args, **kwargs)
-
-        nova = get_nova_admin_connection()
-        current_members = [str(user.memberId) for user in nova.get_project_members(project)]
+        members = get_members(project)
 
         self.fields['username'].queryset = \
-                auth_models.User.objects.exclude(username__in=current_members)
+                auth_models.User.objects.exclude(username__in=members)
+        self.fields['role'].choices = get_roles()
 
 
 class SendCredentialsForm(forms.Form):
@@ -205,7 +229,6 @@
     def __init__(self, *args, **kwargs):
         query_list = kwargs.pop('query_list')
         super(SendCredentialsForm, self).__init__(*args, **kwargs)
-        choices = []
 
         self.fields['users'].choices = [(choices, choices) for choices in query_list]
 

=== modified file 'src/django_nova/manager.py'
--- src/django_nova/manager.py	2011-01-12 20:02:06 +0000
+++ src/django_nova/manager.py	2011-01-15 09:31:13 +0000
@@ -25,7 +25,7 @@
 import boto.s3
 from django.conf import settings
 from django_nova.connection import get_nova_admin_connection
-from django_nova.exceptions import handle_nova_error
+from django_nova.exceptions import wrap_nova_error
 
 
 class ProjectManager(object):
@@ -67,7 +67,7 @@
         except IndexError:
             return None
 
-    @handle_nova_error
+    @wrap_nova_error
     def deregister_image(self, image_id):
         """
         Removes the image's listing but leaves the image
@@ -76,7 +76,7 @@
         conn = self.get_nova_connection()
         return conn.deregister_image(image_id)
 
-    @handle_nova_error
+    @wrap_nova_error
     def update_image(self, image_id, display_name=None, description=None):
         conn = self.get_nova_connection()
         params = {
@@ -86,7 +86,7 @@
                  }
         return conn.get_object('UpdateImage', params, boto.ec2.image.Image)
 
-    @handle_nova_error
+    @wrap_nova_error
     def run_instances(self, image_id, **kwargs):
         """
         Runs instances of the specified image id.
@@ -103,7 +103,7 @@
         except:
             return None
 
-    @handle_nova_error
+    @wrap_nova_error
     def get_instances(self):
         """
         Returns all instances in this project.
@@ -116,7 +116,7 @@
                 instances.append(instance)
         return instances
 
-    @handle_nova_error
+    @wrap_nova_error
     def get_instance(self, instance_id):
         """
         Returns detail about the specified instance.
@@ -130,7 +130,7 @@
                     return instance
         return None
 
-    @handle_nova_error
+    @wrap_nova_error
     def update_instance(self, instance_id, updates):
         conn = self.get_nova_connection()
         params = {'InstanceId': instance_id, 'DisplayName': updates['nickname'],
@@ -163,13 +163,13 @@
 
         return key.read()
 
-    @handle_nova_error
+    @wrap_nova_error
     def terminate_instance(self, instance_id):
         """ Terminates the specified instance within this project. """
         conn = self.get_nova_connection()
         conn.terminate_instances([instance_id])
 
-    @handle_nova_error
+    @wrap_nova_error
     def get_security_groups(self):
         """
         Returns all security groups associated with this project.
@@ -184,7 +184,7 @@
 
         return groups
 
-    @handle_nova_error
+    @wrap_nova_error
     def get_security_group(self, name):
         """
         Returns the specified security group for this project.
@@ -196,14 +196,14 @@
         except IndexError:
             return None
 
-    @handle_nova_error
+    @wrap_nova_error
     def has_security_group(self, name):
         """
         Indicates whether a security group with the specified name exists in this project.
         """
         return self.get_security_group(name) != None
 
-    @handle_nova_error
+    @wrap_nova_error
     def create_security_group(self, name, description):
         """
         Creates a new security group in this project.
@@ -211,7 +211,7 @@
         conn = self.get_nova_connection()
         return conn.create_security_group(name, description)
 
-    @handle_nova_error
+    @wrap_nova_error
     def delete_security_group(self, name):
         """
         Deletes a security group from the project.
@@ -219,7 +219,7 @@
         conn = self.get_nova_connection()
         return conn.delete_security_group(name = name)
 
-    @handle_nova_error
+    @wrap_nova_error
     def authorize_security_group(self, group_name, ip_protocol, from_port, to_port):
         """
         Authorizes a rule for the specified security group.
@@ -233,7 +233,7 @@
             cidr_ip = '0.0.0.0/0'
         )
 
-    @handle_nova_error
+    @wrap_nova_error
     def revoke_security_group(self, group_name, ip_protocol, from_port, to_port):
         """
         Revokes a rule for the specified security group.
@@ -247,7 +247,7 @@
             cidr_ip = '0.0.0.0/0'
         )
 
-    @handle_nova_error
+    @wrap_nova_error
     def get_key_pairs(self):
         """
         Returns all key pairs associated with this project.
@@ -262,7 +262,7 @@
 
         return keys
 
-    @handle_nova_error
+    @wrap_nova_error
     def get_key_pair(self, name):
         """
         Returns the specified security group for this project.
@@ -274,14 +274,14 @@
         except IndexError:
             return None
 
-    @handle_nova_error
+    @wrap_nova_error
     def has_key_pair(self, name):
         """
         Indicates whether a key pair with the specified name exists in this project.
         """
         return self.get_key_pair(name) != None
 
-    @handle_nova_error
+    @wrap_nova_error
     def create_key_pair(self, name):
         """
         Creates a new key pair for this project.
@@ -289,7 +289,7 @@
         conn = self.get_nova_connection()
         return conn.create_key_pair(name)
 
-    @handle_nova_error
+    @wrap_nova_error
     def delete_key_pair(self, name):
         """
         Deletes a new key pair from this project.
@@ -297,7 +297,7 @@
         conn = self.get_nova_connection()
         conn.delete_key_pair(name)
 
-    @handle_nova_error
+    @wrap_nova_error
     def get_volumes(self):
         """
         Returns all volumes in this project.
@@ -305,7 +305,7 @@
         conn = self.get_nova_connection()
         return conn.get_all_volumes()
 
-    @handle_nova_error
+    @wrap_nova_error
     def create_volume(self, size, display_name=None, display_description=None,
                       snapshot=None):
         conn = self.get_nova_connection()
@@ -313,17 +313,17 @@
                   'DisplayDescription': display_description}
         return conn.get_object('CreateVolume', params, boto.ec2.volume.Volume)
 
-    @handle_nova_error
+    @wrap_nova_error
     def delete_volume(self, volume_id):
         conn = self.get_nova_connection()
         return conn.delete_volume(volume_id)
 
-    @handle_nova_error
+    @wrap_nova_error
     def attach_volume(self, volume_id, instance_id, device):
         conn = self.get_nova_connection()
         return conn.attach_volume(volume_id, instance_id, device)
 
-    @handle_nova_error
+    @wrap_nova_error
     def detach_volume(self, volume_id):
         conn = self.get_nova_connection()
         return conn.detach_volume(volume_id)

=== modified file 'src/django_nova/shortcuts.py'
--- src/django_nova/shortcuts.py	2011-01-12 20:02:06 +0000
+++ src/django_nova/shortcuts.py	2011-01-15 09:31:13 +0000
@@ -25,8 +25,10 @@
 from django.http import Http404
 from django_nova import manager
 from django_nova.connection import get_nova_admin_connection
-
-
+from django_nova.exceptions import wrap_nova_error
+
+
+@wrap_nova_error
 def get_project_or_404(request, project_id):
     """
     Returns a project or 404s if it doesn't exist.
@@ -46,6 +48,7 @@
     return manager.ProjectManager(request.user, project, region)
 
 
+@wrap_nova_error
 def get_projects(user):
     """
     Returns a list of projects for a user.
@@ -102,6 +105,7 @@
     request.session['region'] = region_name
 
 
+@wrap_nova_error
 def get_user_image_permissions(username, project_name):
     """
     Returns true if user is a sysadmin and can modify image attributes.

=== modified file 'src/django_nova/urls/project.py'
--- src/django_nova/urls/project.py	2011-01-12 20:02:06 +0000
+++ src/django_nova/urls/project.py	2011-01-15 09:31:13 +0000
@@ -15,6 +15,7 @@
 #    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 #    License for the specific language governing permissions and limitations
 #    under the License.
+
 """
 URL patterns for managing Nova projects.
 """

=== modified file 'src/django_nova/views/images.py'
--- src/django_nova/views/images.py	2011-01-12 20:02:06 +0000
+++ src/django_nova/views/images.py	2011-01-15 09:31:13 +0000
@@ -28,9 +28,9 @@
 from django.contrib import messages
 from django.contrib.auth.decorators import login_required
 from django.shortcuts import redirect, render_to_response
-from django.views.decorators.cache import never_cache
 from django_nova import exceptions
 from django_nova import forms
+from django_nova.exceptions import handle_nova_error
 from django_nova.shortcuts import get_project_or_404, get_projects, get_user_image_permissions
 
 
@@ -50,7 +50,7 @@
 
 
 @login_required
-@never_cache
+@handle_nova_error
 def index(request, project_id):
     project = get_project_or_404(request, project_id)
     project_list = get_projects(request.user)
@@ -67,6 +67,7 @@
 
 
 @login_required
+@handle_nova_error
 def launch(request, project_id, image_id):
     project = get_project_or_404(request, project_id)
     project_list = get_projects(request.user)
@@ -107,7 +108,7 @@
 
 
 @login_required
-@never_cache
+@handle_nova_error
 def detail(request, project_id, image_id):
     project = get_project_or_404(request, project_id)
     project_list = get_projects(request.user)
@@ -133,7 +134,7 @@
 
 
 @login_required
-@never_cache
+@handle_nova_error
 def remove(request, project_id, image_id):
     project = get_project_or_404(request, project_id)
 
@@ -163,7 +164,7 @@
 
 
 @login_required
-@never_cache
+@handle_nova_error
 def privacy(request, project_id, image_id):
     project = get_project_or_404(request, project_id)
     conn = project.get_nova_connection()
@@ -196,7 +197,7 @@
 
 
 @login_required
-@never_cache
+@handle_nova_error
 def update(request, project_id, image_id):
     project = get_project_or_404(request, project_id)
     project_list = get_projects(request.user)

=== modified file 'src/django_nova/views/instances.py'
--- src/django_nova/views/instances.py	2011-01-12 20:02:06 +0000
+++ src/django_nova/views/instances.py	2011-01-15 09:31:13 +0000
@@ -25,14 +25,14 @@
 from django.contrib import messages
 from django.contrib.auth.decorators import login_required
 from django.shortcuts import redirect, render_to_response
-from django.views.decorators.cache import never_cache
 from django_nova import exceptions
 from django_nova import forms as nova_forms
+from django_nova.exceptions import handle_nova_error
 from django_nova.shortcuts import get_project_or_404, get_projects
 
 
 @login_required
-@never_cache
+@handle_nova_error
 def index(request, project_id):
     project = get_project_or_404(request, project_id)
     project_list = get_projects(request.user)
@@ -50,7 +50,7 @@
 
 
 @login_required
-@never_cache
+@handle_nova_error
 def detail(request, project_id, instance_id):
     project = get_project_or_404(request, project_id)
     project_list = get_projects(request.user)
@@ -74,7 +74,7 @@
 
 
 @login_required
-@never_cache
+@handle_nova_error
 def performance(request, project_id, instance_id):
     project = get_project_or_404(request, project_id)
     project_list = get_projects(request.user)
@@ -95,7 +95,6 @@
 
 
 # TODO(devcamcar): Wrap this in an @ajax decorator.
-@never_cache
 def refresh(request, project_id):
     # TODO(devcamcar): This logic belongs in decorator.
     if not request.user.is_authenticated():
@@ -110,7 +109,7 @@
     }, context_instance = template.RequestContext(request))
 
 
-@never_cache
+@handle_nova_error
 def refresh_detail(request, project_id, instance_id):
     # TODO(devcamcar): This logic belongs in decorator.
     if not request.user.is_authenticated():
@@ -128,7 +127,7 @@
 
 
 @login_required
-@never_cache
+@handle_nova_error
 def terminate(request, project_id):
     project = get_project_or_404(request, project_id)
 
@@ -146,6 +145,7 @@
 
 
 @login_required
+@handle_nova_error
 def console(request, project_id, instance_id):
     project = get_project_or_404(request, project_id)
     conn = project.get_nova_connection()
@@ -158,10 +158,12 @@
 
 
 @login_required
+@handle_nova_error
 def graph(request, project_id, instance_id, graph_name):
     project = get_project_or_404(request, project_id)
     graph = project.get_instance_graph(instance_id, graph_name)
-    if graph == None:
+
+    if graph is None:
         raise http.Http404()
 
     response = http.HttpResponse(mimetype='image/png')
@@ -171,14 +173,14 @@
 
 
 @login_required
-@never_cache
+@handle_nova_error
 def update(request, project_id, instance_id):
     project = get_project_or_404(request, project_id)
     project_list = get_projects(request.user)
     page_type = "instances"
     instance = project.get_instance(instance_id)
 
-    if instance == None:
+    if instance is None:
         raise http.Http404()
 
     if request.method == 'POST':

=== modified file 'src/django_nova/views/keypairs.py'
--- src/django_nova/views/keypairs.py	2011-01-12 20:02:06 +0000
+++ src/django_nova/views/keypairs.py	2011-01-15 09:31:13 +0000
@@ -25,14 +25,14 @@
 from django.contrib import messages
 from django.contrib.auth.decorators import login_required
 from django.shortcuts import redirect, render_to_response
-from django.views.decorators.cache import never_cache
 from django_nova import exceptions
 from django_nova import forms
+from django_nova.exceptions import handle_nova_error
 from django_nova.shortcuts import get_project_or_404, get_projects
 
 
 @login_required
-@never_cache
+@handle_nova_error
 def index(request, project_id, download_key=None):
     project = get_project_or_404(request, project_id)
     project_list = get_projects(request.user)
@@ -50,7 +50,7 @@
     }, context_instance = template.RequestContext(request))
 
 @login_required
-@never_cache
+@handle_nova_error
 def add(request, project_id):
     project = get_project_or_404(request, project_id)
     project_list = get_projects(request.user)
@@ -94,7 +94,7 @@
     return redirect('nova_keypairs', project_id)
 
 @login_required
-@never_cache
+@handle_nova_error
 def delete(request, project_id):
     project = get_project_or_404(request, project_id)
 
@@ -105,7 +105,7 @@
             project.delete_key_pair(key_name)
         except exceptions.NovaResponseError, e:
             messages.error(request,
-                           'Unable to delete key: %s - %s (%s)' % \
+                           'Unable to delete key: %s - %s' % \
                            (e.code, e.message,))
         else:
             messages.success(request,
@@ -115,7 +115,7 @@
     return redirect('nova_keypairs', project_id)
 
 @login_required
-@never_cache
+@handle_nova_error
 def download(request, project_id, key_name):
     # Ensure the project exists.
     get_project_or_404(request, project_id)

=== modified file 'src/django_nova/views/projects.py'
--- src/django_nova/views/projects.py	2011-01-12 20:02:06 +0000
+++ src/django_nova/views/projects.py	2011-01-15 09:31:13 +0000
@@ -25,14 +25,14 @@
 from django.contrib.auth import models as auth_models
 from django.contrib.auth.decorators import login_required
 from django.shortcuts import redirect, render_to_response
-from django.views.decorators.cache import never_cache
 from django_nova import forms as nova_forms
 from django_nova.connection import get_nova_admin_connection
+from django_nova.exceptions import handle_nova_error
 from django_nova.shortcuts import get_project_or_404, get_projects
 
 
 @login_required
-@never_cache
+@handle_nova_error
 def detail(request, project_id):
     project = get_project_or_404(request, project_id)
     project_list = get_projects(user=request.user)
@@ -46,11 +46,12 @@
 
 
 @login_required
-@never_cache
+@handle_nova_error
 def manage(request, project_id):
     project = get_project_or_404(request, project_id)
     project_list = get_projects(user=request.user)
-    if project.projectManagerId <> request.user.username:
+
+    if project.projectManagerId != request.user.username:
         return redirect('login')
 
     nova = get_nova_admin_connection()
@@ -86,7 +87,7 @@
 
 
 @login_required
-@never_cache
+@handle_nova_error
 def edit_user(request, project_id, project_user):
     nova = get_nova_admin_connection()
     userroles = nova.get_user_roles(project_user,  project_id)
@@ -94,7 +95,7 @@
     project_list = get_projects(user=request.user)
     edit_user = nova.get_user(project_user)
 
-    if project.projectManagerId <> request.user.username:
+    if project.projectManagerId != request.user.username:
         return redirect('login')
 
     try:
@@ -130,7 +131,7 @@
 
 
 @login_required
-@never_cache
+@handle_nova_error
 def download_credentials(request, project_id):
     project = get_project_or_404(request, project_id)
 

=== modified file 'src/django_nova/views/securitygroups.py'
--- src/django_nova/views/securitygroups.py	2011-01-12 20:02:06 +0000
+++ src/django_nova/views/securitygroups.py	2011-01-15 09:31:13 +0000
@@ -25,14 +25,14 @@
 from django.contrib import messages
 from django.contrib.auth.decorators import login_required
 from django.shortcuts import redirect, render_to_response
-from django.views.decorators.cache import never_cache
 from django_nova import exceptions
 from django_nova import forms
+from django_nova.exceptions import handle_nova_error
 from django_nova.shortcuts import get_project_or_404
 
 
 @login_required
-@never_cache
+@handle_nova_error
 def index(request, project_id):
     project = get_project_or_404(request, project_id)
     securitygroups = project.get_security_groups()
@@ -46,7 +46,7 @@
 
 
 @login_required
-@never_cache
+@handle_nova_error
 def detail(request, project_id, group_name):
     project = get_project_or_404(request, project_id)
     securitygroup = project.get_security_group(group_name)
@@ -62,7 +62,7 @@
 
 
 @login_required
-@never_cache
+@handle_nova_error
 def add(request, project_id):
     project = get_project_or_404(request, project_id)
 
@@ -95,7 +95,7 @@
 
 
 @login_required
-@never_cache
+@handle_nova_error
 def authorize(request, project_id, group_name):
     project = get_project_or_404(request, project_id)
 
@@ -137,7 +137,7 @@
 
 
 @login_required
-@never_cache
+@handle_nova_error
 def revoke(request, project_id, group_name):
     project = get_project_or_404(request, project_id)
 
@@ -164,7 +164,7 @@
 
 
 @login_required
-@never_cache
+@handle_nova_error
 def delete(request, project_id, group_name):
     project = get_project_or_404(request, project_id)