[PR] Skip handling & logging when there are no handlers

[kopf-archiver]

A pull request by nolar at 2019-06-06 17:11:49+00:00
Original URL: zalando-incubator/kopf#103
Merged by nolar at 2019-06-12 13:35:22+00:00

Issue : #60

Description

Currently, if there are no handlers, the handling attempt is anyway done, and the messages are logged that all handlers (zero out of zero) have succeeded.

With this PR, Kopf does not even attempt doing the handling cycle, if there are no handlers for the current event/cause. This also eliminates the unnecessary logging for fake handling cycles.

Notes

This PR is part of a chain leading to the resuming handlers on operator restarts: #103 -> #104 -> #105.

Refactoring

For simplicity in the future, a little refactoring is also performed: all causes are grouped into the internal and user-facing causes.

Also, the handling stack is now one call shorter (the all-purpose execute() is bypassed):

• Now:custom_object_handler→handle_cause→_execute→call_handler
• Was: custom_object_handler→handle_cause→execute→_execute→call_handler

Types of Changes

• Refactor/improvements