K8s-event logging

[nolar]

It would be convenient, if all the important log messages are automatically sent to K8s events, same as they are logged to stdout/stderr.

Only the important messages, not the debug messages.

Both Kopf-internal messages (already sent to k8s now), and the operator-produced messages (as logged via the per-object logger kwarg).

There should be a way to opt out at least on a per-message level — i.e. to explicitly say to not send it as a k8s-event, but to keep it as a log message only (except as logging it as a debug-message).

import kopf

@kopf.on.create('zalando.org', 'v1', 'kopfexamples')
def create_fn(spec, logger, **kwargs):
    image = spec.get('image')
    if not image.startswith('trusted.repo.com/'):
        logger.warning("Only images from trusted.repo.com are trusted. "
                       "Got potentially insecure image %r", image)

This will hide Kopf's explicit k8s-event-sending routines — as it goes against Kopf's mission (of not being a K8s client library). But this will integrate Python logging machinery into K8s's logging/eventing subsystem — which perfectly fits into Kopf's mission of bringing Pythonic ways of coding to the K8s operators field.