While implementing some Neutron extension, I noticed that whenever a parameter
that is expected by the API is not entered, we receive an internal error
message. However, from the user/operator/dev calling the API, it might not be
clear what the error is. Therefore, we should at least, log these validation
errors.
This patch proposes to enclose the call to Controller.prepare_request_body with
a try/except block, and then we log the exception in warning level. After
logging the exception, we raise it to allow the normal execution flow to
continue.
Change-Id: I855442ee8c0c4b4f0aff19968a5db07fca898146