Expose the underlying zap logger

[calind]

I have a following use case: i'm writing an app which exposes some kubernetes suff over grpc. The grpc part of the application already has zap integration and just expects a zap logger passed in. I would like to pass the logger configured by the controller-runtime becuse it's deals nicely with kubernetes objects already but that's not exposed.

I would propose to add an option to Logger and LoggerTo which sets zap default loggers or expose the underlying zap logger.

[DirectXMan12]

/kind feature
/priority backlog

In the short term: you can always make use of the KubeAwareEncoder in your own zap instance.
In the long term: we can probably refactor out the "set up Zap" function pretty easily so that you can just call that directly. Then, if you want to re-use the Zap logger, you could just

import (
    crzap "sigs.k8s.io/controller-runtime/pkg/log/zap"
    "github.com/go-logr/zapr"
    logf "sigs.k8s.io/controller-runtime/pkg/log"
)

func main() {
    // instead of `log := crzap.Logger(isDevel)`
    zapLogger := crzap.RawLoggerTo(dest, isDevel)
    go doSomeNonControllerRuntimeStuff(zapLogger)
    logf.SetLogger(zapr.NewLogger(zapLogger))
}

[calind]

Great! I will attempt a pull request.