make logr understand kubernetes object

Author: caozhuozi

pkg/log/logr/logr.go

@@ -0,0 +1,127 @@
+/*
+Copyright 2025 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// Package logr contains helpers for setting up a Kubernetes object aware logr.Logger.
+package logr
+
+import (
+	"reflect"
+
+	"github.com/go-logr/logr"
+	"k8s.io/apimachinery/pkg/api/meta"
+	"k8s.io/apimachinery/pkg/runtime"
+)
+
+var _ logr.LogSink = (*KubeAwareSink)(nil)
+
+// KubeAwareSink is a logr.LogSink that understands Kubernetes objects.
+type KubeAwareSink struct {
+	sink logr.LogSink
+}
+
+// KubeAware wraps a logr.logger to make it aware of Kubernetes objects.
+func KubeAware(logger logr.Logger) logr.Logger {
+	return logr.New(
+		&KubeAwareSink{logger.GetSink()},
+	)
+}
+
+// Init implements logr.LogSink.
+func (k *KubeAwareSink) Init(info logr.RuntimeInfo) {
+	k.sink.Init(info)
+}
+
+// Enabled implements logr.LogSink.
+func (k *KubeAwareSink) Enabled(level int) bool {
+	return k.sink.Enabled(level)
+}
+
+// Info implements logr.LogSink.
+func (k *KubeAwareSink) Info(level int, msg string, keysAndValues ...interface{}) {
+	k.sink.Info(level, msg, k.wrapKeyAndValues(keysAndValues)...)
+}
+
+// Error implements logr.LogSink.
+func (k *KubeAwareSink) Error(err error, msg string, keysAndValues ...interface{}) {
+	k.sink.Error(err, msg, k.wrapKeyAndValues(keysAndValues)...)
+}
+
+// WithValues implements logr.LogSink.
+func (k *KubeAwareSink) WithValues(keysAndValues ...interface{}) logr.LogSink {
+	return &KubeAwareSink{
+		sink: k.sink.WithValues(k.wrapKeyAndValues(keysAndValues)...),
+	}
+}
+
+// WithName implements logr.LogSink.
+func (k *KubeAwareSink) WithName(name string) logr.LogSink {
+	return &KubeAwareSink{
+		sink: k.sink.WithName(name),
+	}
+}
+
+// wrapKeyAndValues replaces Kubernetes objects with [kubeObjectWrapper].
+func (k *KubeAwareSink) wrapKeyAndValues(keysAndValues []interface{}) []interface{} {
+	result := make([]interface{}, len(keysAndValues))
+	for i, item := range keysAndValues {
+		if i%2 == 0 {
+			// item is key, no need to resolve
+			result[i] = item
+			continue
+		}
+
+		switch val := item.(type) {
+		case runtime.Object:
+			result[i] = &kubeObjectWrapper{obj: val}
+		default:
+			result[i] = item
+		}
+	}
+	return result
+}
+
+var _ logr.Marshaler = (*kubeObjectWrapper)(nil)
+
+// kubeObjectWrapper is a wrapper around runtime.Object that implements logr.Marshaler.
+type kubeObjectWrapper struct {
+	obj runtime.Object
+}
+
+// MarshalLog implements logr.Marshaler.
+// The implementation mirrors the behavior of kubeObjectWrapper.MarshalLogObject.
+func (w *kubeObjectWrapper) MarshalLog() interface{} {
+	result := make(map[string]string)
+
+	if reflect.ValueOf(w.obj).IsNil() {
+		return "got nil for runtime.Object"
+	}
+
+	if gvk := w.obj.GetObjectKind().GroupVersionKind(); gvk.Version != "" {
+		result["apiVersion"] = gvk.GroupVersion().String()
+		result["kind"] = gvk.Kind
+	}
+
+	objMeta, err := meta.Accessor(w.obj)
+	if err != nil {
+		return result
+	}
+
+	if ns := objMeta.GetNamespace(); ns != "" {
+		result["namespace"] = ns
+	}
+	result["name"] = objMeta.GetName()
+	return result
+}

pkg/log/zap/zap.go

@@ -28,6 +28,8 @@ import (
 	"github.com/go-logr/zapr"
 	"go.uber.org/zap"
 	"go.uber.org/zap/zapcore"
+
+	logrhelper "sigs.k8s.io/controller-runtime/pkg/log/logr"
 )
 
 // EncoderConfigOption is a function that can modify a `zapcore.EncoderConfig`.
@@ -36,11 +38,14 @@ type EncoderConfigOption func(*zapcore.EncoderConfig)
 // NewEncoderFunc is a function that creates an Encoder using the provided EncoderConfigOptions.
 type NewEncoderFunc func(...EncoderConfigOption) zapcore.Encoder
 
-// New returns a brand new Logger configured with Opts. It
-// uses KubeAwareEncoder which adds Type information and
-// Namespace/Name to the log.
+// New returns a brand new Logger configured with Opts.
+// It uses [logrhelper.KubeAware] to make the logger Kubernetes-aware,
+// meaning that for Kubernetes objects, the logger will by default digest only the metadata.
 func New(opts ...Opts) logr.Logger {
-	return zapr.NewLogger(NewRaw(opts...))
+	zrl := zapr.NewLogger(NewRaw(opts...))
+	// Make sure the created logr.logger is Kubernetes-aware.
+	// See https://github.com/kubernetes-sigs/controller-runtime/issues/1290 for the background.
+	return logrhelper.KubeAware(zrl)
 }
 
 // Opts allows to manipulate Options.

pkg/log/zap/zap_test.go

@@ -264,6 +264,59 @@ var _ = Describe("Zap logger setup", func() {
 				outRaw := logOut.Bytes()
 				Expect(string(outRaw)).Should(ContainSubstring("got nil for runtime.Object"))
 			})
+
+			It("should log a standard namespaced when using logrLogger.WithValues", func() {
+				name := types.NamespacedName{Name: "some-pod", Namespace: "some-ns"}
+				logger.WithValues("thing", name).Info("here's a kubernetes object")
+
+				outRaw := logOut.Bytes()
+				res := map[string]interface{}{}
+				Expect(json.Unmarshal(outRaw, &res)).To(Succeed())
+
+				Expect(res).To(HaveKeyWithValue("thing", map[string]interface{}{
+					"name":      name.Name,
+					"namespace": name.Namespace,
+				}))
+			})
+
+			It("should log a standard Kubernetes objects when using logrLogger.WithValues", func() {
+				node := &corev1.Node{}
+				node.Name = "a-node"
+				node.APIVersion = "v1"
+				node.Kind = "Node"
+				logger.WithValues("thing", node).Info("here's a kubernetes object")
+
+				outRaw := logOut.Bytes()
+				res := map[string]interface{}{}
+				Expect(json.Unmarshal(outRaw, &res)).To(Succeed())
+
+				Expect(res).To(HaveKeyWithValue("thing", map[string]interface{}{
+					"name":       node.Name,
+					"apiVersion": node.APIVersion,
+					"kind":       node.Kind,
+				}))
+			})
+
+			It("should log a standard unstructured Kubernetes object when using logrLogger.WithValues", func() {
+				pod := &unstructured.Unstructured{
+					Object: map[string]interface{}{
+						"metadata": map[string]interface{}{
+							"name":      "a-pod",
+							"namespace": "a-ns",
+						},
+					},
+				}
+				logger.WithValues("thing", pod).Info("here's a kubernetes object")
+
+				outRaw := logOut.Bytes()
+				res := map[string]interface{}{}
+				Expect(json.Unmarshal(outRaw, &res)).To(Succeed())
+
+				Expect(res).To(HaveKeyWithValue("thing", map[string]interface{}{
+					"name":      "a-pod",
+					"namespace": "a-ns",
+				}))
+			})
 		}
 
 		Context("with logger created using New", func() {