Incorrectly writes events.json with null entry, despite being unauthorized

[jchesterpivotal]

Problem

Job logs/events are often private, even if the overall pipeline is public. In the original events.log implementation, receiving a "not authorized" message from the ATC would lead to skipping writing the events.log file.

Because the logic for events.json follows a distinct path, it is not correctly skipping. Instead, it collects events and stores them in a null, which is faithfully written out to disk. This is because whereas the events.log file is handled in a single specialised method, events.json is handled by two routines following the convention of other endpoints: a fetch method and a write method.

The presence of an incomplete events.json file confuses downstream tools which expect the existence/non-existence of the file to signal whether the events could be retrieved.

Solution

Stop doing that. The logic which fetches events for encoding as a JSON array embedded in events.json should somehow signal that the file is not to be written.