os-server-external-events does not behave correctly for failed single events

[Surya Seetharaman]

The "os-server-external-events" API does not behave correctly when the request body contains a list of one event and if that event ends up in a non-200 state, i.e if the event ends up in either 400 or 404 or 422 states, the function executes all the way to L147 (https://github.com/openstack/nova/blob/433b1662e48db57aaa42e11756fa4a6d8722b386/nova/api/openstack/compute/server_external_events.py#L147) and overall returns a 404 HTTP response without any body. This is wrong since as per the documentation it should return the respective codes (422/404/400) to the client.

Infact correctly speaking, if out of the list of provided events, if at least one of them doesn't get into the "accepted_events" list, rest of them are discarded without returning the correct response against each event.

[Matt Riedemann (mriedem)]

Some discussion about this bug in IRC:

http://eavesdrop.openstack.org/irclogs/%23openstack-nova/%23openstack-nova.2019-08-13.log.html#t2019-08-13T13:36:21

[Eric Fried (efried)]

Sorry, I didn't know about this bug when we opened 1855752. The issue has been fixed under that bug.