tree d18e0368dd8259ed8587b0610b8e87e6903b9b33
parent 8c93be556687f1bbc471d59e6a5f0297bde8f5f1
author Ivan Frade <ifrade@google.com> 1630534818 -0700
committer Ivan Frade <ifrade@google.com> 1630595545 -0700

REST endpoint: Give a more descriptive response

A request to the plugin returns "204 No content" on success, and a
generic 500 on any error without any more details. Provide the caller
with more information, so they know what happened and if they should
retry.

New responses:
* A noop call (no projects to update) returns "204 No content"
* A successfull update returns "200 OK"
* A problem in conf is a "412 Precondition Failure"
* An exception return 500 (as before) but now with an error message.

Change-Id: I453b3a674cb252b79d02b65d5255675a1d7dd291