Enable JSON logging for Karmada controller manager (#6409)

Signed-off-by: Joe Nathan Abellard <[email protected]>

Author: jabellard

artifacts/deploy/karmada-controller-manager.yaml

@@ -41,6 +41,7 @@ spec:
             - --metrics-bind-address=$(POD_IP):8080
             - --health-probe-bind-address=$(POD_IP):10357
             - --enable-no-execute-taint-eviction=true
+            - --logging-format=json
             - --v=4
           livenessProbe:
             httpGet:

cmd/controller-manager/app/controllermanager.go

@@ -31,6 +31,8 @@ import (
 	"k8s.io/client-go/rest"
 	"k8s.io/client-go/util/flowcontrol"
 	cliflag "k8s.io/component-base/cli/flag"
+	"k8s.io/component-base/logs"
+	logsv1 "k8s.io/component-base/logs/api/v1"
 	"k8s.io/component-base/term"
 	"k8s.io/klog/v2"
 	resourceclient "k8s.io/metrics/pkg/client/clientset/versioned/typed/metrics/v1beta1"
@@ -97,44 +99,52 @@ import (
 
 // NewControllerManagerCommand creates a *cobra.Command object with default parameters
 func NewControllerManagerCommand(ctx context.Context) *cobra.Command {
+	logConfig := logsv1.NewLoggingConfiguration()
+	fss := cliflag.NamedFlagSets{}
+
+	logsFlagSet := fss.FlagSet("logs")
+	logs.AddFlags(logsFlagSet, logs.SkipLoggingConfigurationFlags())
+	logsv1.AddFlags(logConfig, logsFlagSet)
+	klogflag.Add(logsFlagSet)
+
+	genericFlagSet := fss.FlagSet("generic")
+	// Add the flag(--kubeconfig) that is added by controller-runtime.
+	// (https://github.com/kubernetes-sigs/controller-runtime/blob/v0.11.1/pkg/client/config/config.go#L39),
+	// and update the flag usage.
+	genericFlagSet.AddGoFlagSet(flag.CommandLine)
+	genericFlagSet.Lookup("kubeconfig").Usage = "Path to karmada control plane kubeconfig file."
 	opts := options.NewOptions()
+	opts.AddFlags(genericFlagSet, controllers.ControllerNames(), sets.List(controllersDisabledByDefault))
 
 	cmd := &cobra.Command{
 		Use: names.KarmadaControllerManagerComponentName,
 		Long: `The karmada-controller-manager runs various controllers.
-The controllers watch Karmada objects and then talk to the underlying clusters' API servers
-to create regular Kubernetes resources.`,
+		The controllers watch Karmada objects and then talk to the underlying
+		clusters' API servers to create regular Kubernetes resources.`,
+
+		PersistentPreRunE: func(_ *cobra.Command, _ []string) error {
+			if err := logsv1.ValidateAndApply(logConfig, features.FeatureGate); err != nil {
+				return err
+			}
+			logs.InitLogs()
+			return nil
+		},
+
 		RunE: func(_ *cobra.Command, _ []string) error {
-			// validate options
 			if errs := opts.Validate(); len(errs) != 0 {
 				return errs.ToAggregate()
 			}
-
 			return Run(ctx, opts)
 		},
 	}
 
-	fss := cliflag.NamedFlagSets{}
-
-	// Set generic flags
-	genericFlagSet := fss.FlagSet("generic")
-	// Add the flag(--kubeconfig) that is added by controller-runtime
-	// (https://github.com/kubernetes-sigs/controller-runtime/blob/v0.11.1/pkg/client/config/config.go#L39),
-	// and update the flag usage.
-	genericFlagSet.AddGoFlagSet(flag.CommandLine)
-	genericFlagSet.Lookup("kubeconfig").Usage = "Path to karmada control plane kubeconfig file."
-	opts.AddFlags(genericFlagSet, controllers.ControllerNames(), sets.List(controllersDisabledByDefault))
-
-	// Set klog flags
-	logsFlagSet := fss.FlagSet("logs")
-	klogflag.Add(logsFlagSet)
-
 	cmd.AddCommand(sharedcommand.NewCmdVersion(names.KarmadaControllerManagerComponentName))
 	cmd.Flags().AddFlagSet(genericFlagSet)
 	cmd.Flags().AddFlagSet(logsFlagSet)
 
 	cols, _, _ := term.TerminalSize(cmd.OutOrStdout())
 	sharedcli.SetUsageAndHelpFunc(cmd, fss, cols)
+
 	return cmd
 }
 

cmd/controller-manager/controller-manager.go

@@ -20,22 +20,18 @@ import (
 	"os"
 
 	"k8s.io/component-base/cli"
-	_ "k8s.io/component-base/logs/json/register" // for JSON log format registration
-	"k8s.io/klog/v2"
+	"k8s.io/component-base/logs"
+	_ "k8s.io/component-base/logs/json/register" // To enable JSON log format support
 	controllerruntime "sigs.k8s.io/controller-runtime"
 
 	"github.com/karmada-io/karmada/cmd/controller-manager/app"
 )
 
 func main() {
 	ctx := controllerruntime.SetupSignalHandler()
-	// Starting from version 0.15.0, controller-runtime expects its consumers to set a logger through log.SetLogger.
-	// If SetLogger is not called within the first 30 seconds of a binaries lifetime, it will get
-	// set to a NullLogSink and report an error. Here's to silence the "log.SetLogger(...) was never called; logs will not be displayed" error
-	// by setting a logger through log.SetLogger.
-	// More info refer to: https://github.com/karmada-io/karmada/pull/4885.
-	controllerruntime.SetLogger(klog.Background())
 	cmd := app.NewControllerManagerCommand(ctx)
-	code := cli.Run(cmd)
-	os.Exit(code)
+	exitCode := cli.Run(cmd)
+	// Ensure any buffered log entries are flushed
+	logs.FlushLogs()
+	os.Exit(exitCode)
 }

pkg/features/features.go

@@ -19,6 +19,7 @@ package features
 import (
 	"k8s.io/apimachinery/pkg/util/runtime"
 	"k8s.io/component-base/featuregate"
+	logsv1 "k8s.io/component-base/logs/api/v1"
 )
 
 const (
@@ -79,6 +80,29 @@ const (
 	// owner: @mszacillo, @RainbowMango, @zhzhuang-zju, @seanlaii, @liwang0513
 	// alpha: v1.14
 	FederatedQuotaEnforcement featuregate.Feature = "FederatedQuotaEnforcement"
+
+	// LoggingAlphaOptions allows fine-tuning of experimental, alpha-quality logging options.
+	// Inherited from Kubernetes. Ref: https://github.com/kubernetes/component-base/blob/release-1.32/logs/api/v1/kube_features.go#L45
+	//
+	// owner: @jabellard
+	// alpha: v1.15
+	LoggingAlphaOptions = logsv1.LoggingAlphaOptions
+
+	// LoggingBetaOptions allows fine-tuning of experimental, beta-quality logging options.
+	// Inherited from Kubernetes. Ref: https://github.com/kubernetes/component-base/blob/release-1.32/logs/api/v1/kube_features.go#L54
+	//
+	// owner: @jabellard
+	// beta: v1.15
+	LoggingBetaOptions = logsv1.LoggingBetaOptions
+
+	// ContextualLogging enables looking up a logger from a context.Context instead of using
+	// the global fallback logger and manipulating the logger that is
+	// used by a call chain.
+	// Inherited from Kubernetes. Ref: https://github.com/kubernetes/component-base/blob/release-1.32/logs/api/v1/kube_features.go#L32
+	//
+	// owner: @jabellard
+	// beta: v1.15
+	ContextualLogging = logsv1.ContextualLogging
 )
 
 var (
@@ -101,6 +125,9 @@ var (
 		StatefulFailoverInjection:         {Default: false, PreRelease: featuregate.Alpha},
 		PriorityBasedScheduling:           {Default: false, PreRelease: featuregate.Alpha},
 		FederatedQuotaEnforcement:         {Default: false, PreRelease: featuregate.Alpha},
+		LoggingAlphaOptions:               {Default: false, PreRelease: featuregate.Alpha},
+		LoggingBetaOptions:                {Default: true, PreRelease: featuregate.Beta},
+		ContextualLogging:                 {Default: true, PreRelease: featuregate.Beta},
 	}
 )