add default for loggingconfiguration struct

cmd/kubelet/app/server.go

@@ -405,9 +405,7 @@ func UnsecuredDependencies(s *options.KubeletServer, featureGate featuregate.Fea
 // not be generated.
 func Run(s *options.KubeletServer, kubeDeps *kubelet.Dependencies, featureGate featuregate.FeatureGate, stopCh <-chan struct{}) error {
 	logOption := logs.NewOptions()
-	if s.Logging.Format != "" {
-		logOption.LogFormat = s.Logging.Format
-	}
+	logOption.LogFormat = s.Logging.Format
 	logOption.Apply()
 	// To help debugging, immediately log version
 	klog.Infof("Version: %+v", version.Get())

pkg/kubelet/apis/config/fuzzer/fuzzer.go

@@ -100,6 +100,9 @@ func Funcs(codecs runtimeserializer.CodecFactory) []interface{} {
 			obj.ConfigMapAndSecretChangeDetectionStrategy = "Watch"
 			obj.AllowedUnsafeSysctls = []string{}
 			obj.VolumePluginDir = kubeletconfigv1beta1.DefaultVolumePluginDir
+			if obj.Logging.Format == "" {
+				obj.Logging.Format = "text"
+			}
 		},
 	}
 }

pkg/kubelet/apis/config/scheme/testdata/KubeletConfiguration/after/v1beta1.yaml

@@ -49,7 +49,8 @@ iptablesMasqueradeBit: 14
 kind: KubeletConfiguration
 kubeAPIBurst: 10
 kubeAPIQPS: 5
-logging: {}
+logging:
+  format: text
 makeIPTablesUtilChains: true
 maxOpenFiles: 1000000
 maxPods: 110

pkg/kubelet/apis/config/scheme/testdata/KubeletConfiguration/roundtrip/default/v1beta1.yaml

@@ -49,7 +49,8 @@ iptablesMasqueradeBit: 14
 kind: KubeletConfiguration
 kubeAPIBurst: 10
 kubeAPIQPS: 5
-logging: {}
+logging:
+  format: text
 makeIPTablesUtilChains: true
 maxOpenFiles: 1000000
 maxPods: 110

pkg/kubelet/apis/config/v1beta1/defaults.go

@@ -21,6 +21,7 @@ import (
 
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	kruntime "k8s.io/apimachinery/pkg/runtime"
+	componentbaseconfigv1alpha1 "k8s.io/component-base/config/v1alpha1"
 	kubeletconfigv1beta1 "k8s.io/kubelet/config/v1beta1"
 	// TODO: Cut references to k8s.io/kubernetes, eventually there should be none from this package
 	"k8s.io/kubernetes/pkg/kubelet/qos"
@@ -233,4 +234,6 @@ func SetDefaults_KubeletConfiguration(obj *kubeletconfigv1beta1.KubeletConfigura
 	if obj.VolumePluginDir == "" {
 		obj.VolumePluginDir = DefaultVolumePluginDir
 	}
+	// Use the Default LoggingConfiguration option
+	componentbaseconfigv1alpha1.RecommendedLoggingConfiguration(&obj.Logging)
 }

staging/src/k8s.io/component-base/config/v1alpha1/defaults.go

@@ -95,3 +95,18 @@ func NewRecommendedDebuggingConfiguration() *DebuggingConfiguration {
 	RecommendedDebuggingConfiguration(ret)
 	return ret
 }
+
+// RecommendedLoggingConfiguration defaults logging configuration.
+// This will set the recommended default
+// values, but they may be subject to change between API versions. This function
+// is intentionally not registered in the scheme as a "normal" `SetDefaults_Foo`
+// function to allow consumers of this type to set whatever defaults for their
+// embedded configs. Forcing consumers to use these defaults would be problematic
+// as defaulting in the scheme is done as part of the conversion, and there would
+// be no easy way to opt-out. Instead, if you want to use this defaulting method
+// run it in your wrapper struct of this type in its `SetDefaults_` method.
+func RecommendedLoggingConfiguration(obj *LoggingConfiguration) {
+	if obj.Format == "" {
+		obj.Format = "text"
+	}
+}