OIF Demo Finding #6 - Need for additional result codes

[openflow-lyo]

Issue Title

• HTTP result codes are not descriptive enough |   Description
• The HTTP result codes (e.g. 40x) do not provide enough information about the API server’s disposition of a request |   Discussion
• Without more explicit result codes, or a verbose reason string, it is hard to debug across the API. May want to look at ONAP VES Resolution (Demo)
• General behavior should be respond with a 4xx when a failure is known (e.g. if path computation fails).  Specific 4xx is not specified at this time but should be as a part of long term work.   Resolution (Long Term) -        open issue on this – needs further work – request Jack to provide information/proposal, e.g., based on ONAP VES work