Fix BarbicanException error propagation in Deckhand by ensuring
that the exception details are passed around via str(e) rather
than e.message as the Barbican exceptions [0] don't have additional
attributes like falcon.
Example stack trace:
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/usr/local/lib/python3.5/dist-packages/falcon/api.py", line 244, in __call__
responder(req, resp, **params)
File "./deckhand/policy.py", line 104, in handler
return func(*args, **kwargs)
File "./deckhand/control/buckets.py", line 70, in on_put
self._prepare_secret_documents(documents)
File "./deckhand/control/buckets.py", line 83, in _prepare_secret_documents
secret_data = self.secrets_mgr.create(document)
File "./deckhand/engine/secrets_manager.py", line 74, in create
resp = self.barbican_driver.create_secret(**kwargs)
File "./deckhand/barbican/driver.py", line 39, in create_secret
LOG.exception(e.message)
AttributeError: 'HTTPServerError' object has no attribute 'message'
[0] https://github.com/openstack/python-barbicanclient/blob/master/barbicanclient/exceptions.py
Change-Id: I58410c3729fe4fd066227311589e5ee5d30dc171
f0cc8b6c1a