For 4xx errors Placement sends back a complex JSON object describing
the error. When turned into an exception that becomes a non-trivial
attribute of the error object. Usual ways of logging an exception (that
is LOG.exception) completely ignore that attribute, therefore the real
error message is not logged. For example we only logged the fact that
we received a BadRequest response and nothing else while Placement did
provide a whole lot more detail. Here we dig out that error detail and
re-throw a better exception with it.
Change-Id: Id97116c1c298f54f898a746d6e3c96b1f412bb49
Related-Bug: #1578989
1e6a07c5fc