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+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2010 United States Government as represented by the
+# Administrator of the National Aeronautics and Space Administration.
+# All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# 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.core import exceptions as core_exceptions
+
+
+class NovaServerError(Exception):
+ """
+ Consumes a BotoServerError and gives more meaningful errors.
+ """
+ def __init__(self, ec2error):
+ self.status = ec2error.status
+ self.message = ec2error.reason
+
+ def __str__(self):
+ return self.message
+
+
+class NovaApiError(Exception):
+ """
+ Used when Nova returns a 400 Bad Request status.
+ """
+ def __init__(self, ec2error):
+ self.message = ec2error.error_message
+
+ def __str__(self):
+ return self.message
+
+
+class NovaUnavailableError(NovaServerError):
+ """
+ Used when Nova returns a 503 Service Unavailable status.
+ """
+ pass
+
+
+class NovaUnauthorizedError(core_exceptions.PermissionDenied):
+ """
+ Used when Nova returns a 401 Not Authorized 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 == 400 and e.error_code == 'ApiError':
+ raise NovaApiError(e)
+ elif e.status == 401:
+ raise NovaUnauthorizedError()
+ elif e.status == 503:
+ raise NovaUnavailableError(e)
+ raise NovaServerError(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
+
+