⚠ pkg/log: Default to NullLogger instead of DelegatingLogger

The DelegatingLogger used by default causes a high number of memory
allocations for controllers when it doesn't get populated. It does so
in a completely invisible manner, because "not populated" also means
that its not going to log anything.

IMHO it is reasonable to expect consumers to set a Logger before
attempting to use it.

Author: alvaroaleman

pkg/log/log.go

@@ -41,13 +41,13 @@ import (
 
 // SetLogger sets a concrete logging implementation for all deferred Loggers.
 func SetLogger(l logr.Logger) {
-	Log.Fulfill(l)
+	Log = l
 }
 
 // Log is the base logger used by kubebuilder.  It delegates
 // to another logr.Logger.  You *must* call SetLogger to
 // get any actual logging.
-var Log = NewDelegatingLogger(NullLogger{})
+var Log logr.Logger = NullLogger{}
 
 // FromContext returns a logger with predefined values from a context.Context.
 func FromContext(ctx context.Context, keysAndValues ...interface{}) logr.Logger {

pkg/log/log_test.go

@@ -92,29 +92,6 @@ func (f *fakeLogger) V(lvl int) logr.InfoLogger { return f }
 
 var _ = Describe("logging", func() {
 
-	Describe("top-level logger", func() {
-		It("hold newly created loggers until a logger is set", func() {
-			By("grabbing a new sub-logger and logging to it")
-			l1 := Log.WithName("runtimeLog").WithValues("newtag", "newvalue1")
-			l1.Info("before msg")
-
-			By("actually setting the logger")
-			logger := &fakeLogger{root: &fakeLoggerRoot{}}
-			SetLogger(logger)
-
-			By("grabbing another sub-logger and logging to both loggers")
-			l2 := Log.WithName("runtimeLog").WithValues("newtag", "newvalue2")
-			l1.Info("after msg 1")
-			l2.Info("after msg 2")
-
-			By("ensuring that messages after the logger was set were logged")
-			Expect(logger.root.messages).To(ConsistOf(
-				logInfo{name: []string{"runtimeLog"}, tags: []interface{}{"newtag", "newvalue1"}, msg: "after msg 1"},
-				logInfo{name: []string{"runtimeLog"}, tags: []interface{}{"newtag", "newvalue2"}, msg: "after msg 2"},
-			))
-		})
-	})
-
 	Describe("lazy logger initialization", func() {
 		var (
 			root     *fakeLoggerRoot