Reuse exceptions from Oslo

- Remove unused exceptions from novaclient.exceptions
- Reuse exceptions from common code

OpenStack clients which already use exception from common code:
- ironicclient   - I784007f36dd6a63fc4c77e0d0f0f000e05eb792f
- keystoneclient - Iedf4e5d753d4278d81751ba0f55fdef3566b56de
- saharaclient
- tuskarclient   - Iacbf219168fae62d864c6594dd41e0737e848cfa

Similar patches in other clients related to reusing exceptions
from common code:
- cinderclient   - I07f04ba5357e0196fe43b510e1d2fff5afa02faa
- glanceclient   - I9838391cff7e450f08d27668564b02e63259186c

Related to blueprint common-client-library-2

Change-Id: Ia35d65d57a0047f88a609070f8b4c76215cbd3e9

novaclient/exceptions.py

@@ -16,161 +16,31 @@
 Exception definitions.
 """
 
+import inspect
+import sys
 
-class UnsupportedVersion(Exception):
+import six
-    """Indicates that the user is trying to use an unsupported
+
-    version of the API.
+from novaclient.openstack.common.apiclient.exceptions import *  # noqa
-    """
+
-    pass
+# NOTE(akurilin): Since v.2.17.0 this alias should be left here to support
+# backwards compatibility.
+OverLimit = RequestEntityTooLarge
 
 
-class CommandError(Exception):
+class NoTokenLookupException(ClientException):
-    pass
-
-
-class AuthorizationFailure(Exception):
-    pass
-
-
-class NoUniqueMatch(Exception):
-    pass
-
-
-class AuthSystemNotFound(Exception):
-    """When the user specify a AuthSystem but not installed."""
-    def __init__(self, auth_system):
-        self.auth_system = auth_system
-
-    def __str__(self):
-        return "AuthSystemNotFound: %s" % repr(self.auth_system)
-
-
-class NoTokenLookupException(Exception):
     """This form of authentication does not support looking up
        endpoints from an existing token.
     """
     pass
 
 
-class EndpointNotFound(Exception):
-    """Could not find Service or Region in Service Catalog."""
-    pass
-
-
-class AmbiguousEndpoints(Exception):
-    """Found more than one matching endpoint in Service Catalog."""
-    def __init__(self, endpoints=None):
-        self.endpoints = endpoints
-
-    def __str__(self):
-        return "AmbiguousEndpoints: %s" % repr(self.endpoints)
-
-
-class ConnectionRefused(Exception):
-    """
-    Connection refused: the server refused the connection.
-    """
-    def __init__(self, response=None):
-        self.response = response
-
-    def __str__(self):
-        return "ConnectionRefused: %s" % repr(self.response)
-
-
 class InstanceInErrorState(Exception):
     """Instance is in the error state."""
     pass
 
 
-class ClientException(Exception):
+class RateLimit(RequestEntityTooLarge):
-    """
-    The base exception class for all exceptions this library raises.
-    """
-    message = 'Unknown Error'
-
-    def __init__(self, code, message=None, details=None, request_id=None,
-                 url=None, method=None):
-        self.code = code
-        self.message = message or self.__class__.message
-        self.details = details
-        self.request_id = request_id
-        self.url = url
-        self.method = method
-
-    def __str__(self):
-        formatted_string = "%s (HTTP %s)" % (self.message, self.code)
-        if self.request_id:
-            formatted_string += " (Request-ID: %s)" % self.request_id
-
-        return formatted_string
-
-
-class BadRequest(ClientException):
-    """
-    HTTP 400 - Bad request: you sent some malformed data.
-    """
-    http_status = 400
-    message = "Bad request"
-
-
-class Unauthorized(ClientException):
-    """
-    HTTP 401 - Unauthorized: bad credentials.
-    """
-    http_status = 401
-    message = "Unauthorized"
-
-
-class Forbidden(ClientException):
-    """
-    HTTP 403 - Forbidden: your credentials don't give you access to this
-    resource.
-    """
-    http_status = 403
-    message = "Forbidden"
-
-
-class NotFound(ClientException):
-    """
-    HTTP 404 - Not found
-    """
-    http_status = 404
-    message = "Not found"
-
-
-class MethodNotAllowed(ClientException):
-    """
-    HTTP 405 - Method Not Allowed
-    """
-    http_status = 405
-    message = "Method Not Allowed"
-
-
-class Conflict(ClientException):
-    """
-    HTTP 409 - Conflict
-    """
-    http_status = 409
-    message = "Conflict"
-
-
-class OverLimit(ClientException):
-    """
-    HTTP 413 - Over limit: you're over the API limits for this time period.
-    """
-    http_status = 413
-    message = "Over limit"
-
-    def __init__(self, *args, **kwargs):
-        try:
-            self.retry_after = int(kwargs.pop('retry_after'))
-        except (KeyError, ValueError):
-            self.retry_after = 0
-
-        super(OverLimit, self).__init__(*args, **kwargs)
-
-
-class RateLimit(OverLimit):
     """
     HTTP 429 - Rate limit: you've sent too many requests for this time period.
     """
@@ -178,25 +48,11 @@ class RateLimit(OverLimit):
     message = "Rate limit"
 
 
-# NotImplemented is a python keyword.
+_code_map = dict(
-class HTTPNotImplemented(ClientException):
+    (getattr(obj, 'http_status', None), obj)
-    """
+    for name, obj in six.iteritems(vars(sys.modules[__name__]))
-    HTTP 501 - Not Implemented: the server does not support this operation.
+    if inspect.isclass(obj) and getattr(obj, 'http_status', False)
-    """
+)
-    http_status = 501
-    message = "Not Implemented"
-
-
-# In Python 2.4 Exception is old-style and thus doesn't have a __subclasses__()
-# so we can do this:
-#     _code_map = dict((c.http_status, c)
-#                      for c in ClientException.__subclasses__())
-#
-# Instead, we have to hardcode it:
-_error_classes = [BadRequest, Unauthorized, Forbidden, NotFound,
-                  MethodNotAllowed, Conflict, OverLimit, RateLimit,
-                  HTTPNotImplemented]
-_code_map = dict((c.http_status, c) for c in _error_classes)
 
 
 def from_response(response, body, url, method=None):
@@ -211,7 +67,7 @@ def from_response(response, body, url, method=None):
             raise exception_from_response(resp, rest.text)
     """
     kwargs = {
-        'code': response.status_code,
+        'http_status': response.status_code,
         'method': method,
         'url': url,
         'request_id': None,

novaclient/tests/test_http.py

@@ -150,7 +150,7 @@ class ClientTest(utils.TestCase):
         # Python 2.7 and testtools doesn't match that implementation yet
         try:
             cl.get('/hi')
-        except exceptions.ClientException as exc:
+        except exceptions.ServiceUnavailable as exc:
-            self.assertIn('Unknown Error', six.text_type(exc))
+            self.assertIn('Service Unavailable (HTTP 503)', six.text_type(exc))
         else:
-            self.fail('Expected exceptions.ClientException')
+            self.fail('Expected exceptions.ServiceUnavailable')