nova shouldn't trust userdata is properly formated by client

[Jesse Andrews]

When experimenting with a recent extension (user_data) in the openstack 1.1 api, I sent non-base64 encoded data.

If you then try to use the metadata api (to retrieve anything - even the instance-id via /latest/meta-data/instance-id) it causes an exception:

(nova.api.ec2.metadata): TRACE: Traceback (most recent call last):
(nova.api.ec2.metadata): TRACE: File "/usr/lib/pymodules/python2.6/nova/api/ec2/metadatarequesthandler.py", line 79, in __call__
(nova.api.ec2.metadata): TRACE: meta_data = self.cc.get_metadata(remote_address)
(nova.api.ec2.metadata): TRACE: File "/usr/lib/pymodules/python2.6/nova/api/ec2/cloud.py", line 299, in get_metadata
(nova.api.ec2.metadata): TRACE: 'user-data': self._format_user_data(instance_ref),
(nova.api.ec2.metadata): TRACE: File "/usr/lib/pymodules/python2.6/nova/api/ec2/cloud.py", line 1020, in _format_user_data
(nova.api.ec2.metadata): TRACE: return base64.b64decode(instance_ref['user_data'])
(nova.api.ec2.metadata): TRACE: File "/usr/lib/python2.6/base64.py", line 76, in b64decode
(nova.api.ec2.metadata): TRACE: raise TypeError(msg)
(nova.api.ec2.metadata): TRACE: TypeError: Incorrect padding

[Tushar Patil (tpatil)]

Please assign this bug to me, if anyone is not working on it.