logrus.Panic and async hook don't work well together

[glasser]

When doing a logrus.Fatal or logrus.Panic, it would be good if an async hook got flushed. With Fatal, this is doable because you can use logrus.RegisterExitHandler to call Flush. But you can't do that for Panic. Is it possible to get a Panic out with an async hook?

I'm thinking maybe Fire should ignore hook.asynchronous for the Panic level (and honestly maybe for the Fatal level too, so you don't have to hook up a Flush).

[glasser]

(I guess you can add a second hook that flushes on Panic and Fatal...)

[glasser]

This is my workaround:

type flushSentryHook struct {
    sentryHook *logrus_sentry.SentryHook
}

func (flushSentryHook) Levels() []logrus.Level {
    return []logrus.Level{logrus.PanicLevel, logrus.FatalLevel}
}
func (fsh flushSentryHook) Fire(*logrus.Entry) error {
    fsh.sentryHook.Flush()
    return nil
}

Then, after adding the sentry hook, also run logrus.AddHook(flushSentryHook{sentryHook: hook}).

[blaskovicz]

@glasser thanks for the snippet. I also wrapped your final shutdown flush in a timeout of its own (so that the wg.Done() of the underlying async hook doesn't wait forever).

https://gist.github.com/blaskovicz/8a61d655cb5ebaab53f6645204aa51b8