Merge pull request kubernetes-sigs#1329 from vincepri/backport-071

🌱 Backport bug fixes for v0.7.1 release

Author: k8s-ci-robot

pkg/log/log.go

@@ -35,18 +35,50 @@ package log
 
 import (
 	"context"
+	"sync"
+	"time"
 
 	"github.com/go-logr/logr"
 )
 
 // SetLogger sets a concrete logging implementation for all deferred Loggers.
 func SetLogger(l logr.Logger) {
+	loggerWasSetLock.Lock()
+	defer loggerWasSetLock.Unlock()
+
+	loggerWasSet = true
 	Log.Fulfill(l)
 }
 
+// It is safe to assume that if this wasn't set within the first 30 seconds of a binaries
+// lifetime, it will never get set. The DelegatingLogger causes a high number of memory
+// allocations when not given an actual Logger, so we set a NullLogger to avoid that.
+//
+// We need to keep the DelegatingLogger because we have various inits() that get a logger from
+// here. They will always get executed before any code that imports controller-runtime
+// has a chance to run and hence to set an actual logger.
+func init() {
+	// Init is blocking, so start a new goroutine
+	go func() {
+		time.Sleep(30 * time.Second)
+		loggerWasSetLock.Lock()
+		defer loggerWasSetLock.Unlock()
+		if !loggerWasSet {
+			Log.Fulfill(NullLogger{})
+		}
+	}()
+}
+
+var (
+	loggerWasSetLock sync.Mutex
+	loggerWasSet     bool
+)
+
 // Log is the base logger used by kubebuilder.  It delegates
-// to another logr.Logger.  You *must* call SetLogger to
-// get any actual logging.
+// to another logr.Logger. You *must* call SetLogger to
+// get any actual logging. If SetLogger is not called within
+// the first 30 seconds of a binaries lifetime, it will get
+// set to a NullLogger.
 var Log = NewDelegatingLogger(NullLogger{})
 
 // FromContext returns a logger with predefined values from a context.Context.

pkg/webhook/admission/response.go

@@ -90,8 +90,14 @@ func PatchResponseFromRaw(original, current []byte) Response {
 	return Response{
 		Patches: patches,
 		AdmissionResponse: admissionv1.AdmissionResponse{
-			Allowed:   true,
-			PatchType: func() *admissionv1.PatchType { pt := admissionv1.PatchTypeJSONPatch; return &pt }(),
+			Allowed: true,
+			PatchType: func() *admissionv1.PatchType {
+				if len(patches) == 0 {
+					return nil
+				}
+				pt := admissionv1.PatchTypeJSONPatch
+				return &pt
+			}(),
 		},
 	}
 }