Moving Kubelet --node-status-max-images flag to configuration

cmd/kubelet/app/options/options.go

@@ -150,9 +150,6 @@ type KubeletFlags struct {
 	// bootstrapCheckpointPath is the path to the directory containing pod checkpoints to
 	// run on restore
 	BootstrapCheckpointPath string
-	// NodeStatusMaxImages caps the number of images reported in Node.Status.Images.
-	// This is an experimental, short-term flag to help with node scalability.
-	NodeStatusMaxImages int32
 
 	// DEPRECATED FLAGS
 	// minimumGCAge is the minimum age for a finished container before it is
@@ -206,7 +203,6 @@ func NewKubeletFlags() *KubeletFlags {
 		RegisterNode:                        true,
 		SeccompProfileRoot:                  filepath.Join(defaultRootDir, "seccomp"),
 		// prior to the introduction of this flag, there was a hardcoded cap of 50 images
-		NodeStatusMaxImages:         50,
 		EnableCAdvisorJSONEndpoints: false,
 	}
 }
@@ -217,9 +213,6 @@ func ValidateKubeletFlags(f *KubeletFlags) error {
 	if f.DynamicConfigDir.Provided() && !utilfeature.DefaultFeatureGate.Enabled(features.DynamicKubeletConfig) {
 		return fmt.Errorf("the DynamicKubeletConfig feature gate must be enabled in order to use the --dynamic-config-dir flag")
 	}
-	if f.NodeStatusMaxImages < -1 {
-		return fmt.Errorf("invalid configuration: NodeStatusMaxImages (--node-status-max-images) must be -1 or greater")
-	}
 
 	unknownLabels := sets.NewString()
 	for k := range f.NodeLabels {
@@ -379,7 +372,6 @@ func (f *KubeletFlags) AddFlags(mainfs *pflag.FlagSet) {
 	fs.BoolVar(&f.ExitOnLockContention, "exit-on-lock-contention", f.ExitOnLockContention, "Whether kubelet should exit upon lock-file contention.")
 	fs.StringVar(&f.SeccompProfileRoot, "seccomp-profile-root", f.SeccompProfileRoot, "<Warning: Alpha feature> Directory path for seccomp profiles.")
 	fs.StringVar(&f.BootstrapCheckpointPath, "bootstrap-checkpoint-path", f.BootstrapCheckpointPath, "<Warning: Alpha feature> Path to the directory where the checkpoints are stored")
-	fs.Int32Var(&f.NodeStatusMaxImages, "node-status-max-images", f.NodeStatusMaxImages, "<Warning: Alpha feature> The maximum number of images to report in Node.Status.Images. If -1 is specified, no cap will be applied.")
 
 	// DEPRECATED FLAGS
 	fs.StringVar(&f.BootstrapKubeconfig, "experimental-bootstrap-kubeconfig", f.BootstrapKubeconfig, "")
@@ -530,6 +522,8 @@ func AddKubeletConfigFlags(mainfs *pflag.FlagSet, c *kubeletconfig.KubeletConfig
 	fs.Int32Var(&c.ContainerLogMaxFiles, "container-log-max-files", c.ContainerLogMaxFiles, "<Warning: Beta feature> Set the maximum number of container log files that can be present for a container. The number must be >= 2. This flag can only be used with --container-runtime=remote.")
 	fs.StringSliceVar(&c.AllowedUnsafeSysctls, "allowed-unsafe-sysctls", c.AllowedUnsafeSysctls, "Comma-separated whitelist of unsafe sysctls or unsafe sysctl patterns (ending in *). Use these at your own risk.")
 
+	fs.Int32Var(&c.NodeStatusMaxImages, "node-status-max-images", c.NodeStatusMaxImages, "The maximum number of images to report in Node.Status.Images. If -1 is specified, no cap will be applied.")
+
 	// Flags intended for testing, not recommended used in production environments.
 	fs.Int64Var(&c.MaxOpenFiles, "max-open-files", c.MaxOpenFiles, "Number of files that can be opened by Kubelet process.")
 

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

@@ -66,6 +66,7 @@ func Funcs(codecs runtimeserializer.CodecFactory) []interface{} {
 			obj.NodeLeaseDurationSeconds = 40
 			obj.CPUManagerPolicy = "none"
 			obj.CPUManagerReconcilePeriod = obj.NodeStatusUpdateFrequency
+			obj.NodeStatusMaxImages = 50
 			obj.TopologyManagerPolicy = kubeletconfig.NoneTopologyManagerPolicy
 			obj.QOSReserved = map[string]string{
 				"memory": "50%",

pkg/kubelet/apis/config/helpers_test.go

@@ -200,9 +200,10 @@ var (
 		"StaticPodURLHeader[*][*]",
 		"MaxOpenFiles",
 		"MaxPods",
+		"NodeLeaseDurationSeconds",
+		"NodeStatusMaxImages",
 		"NodeStatusUpdateFrequency.Duration",
 		"NodeStatusReportFrequency.Duration",
-		"NodeLeaseDurationSeconds",
 		"OOMScoreAdj",
 		"PodCIDR",
 		"PodPidsLimit",

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

@@ -52,6 +52,7 @@ makeIPTablesUtilChains: true
 maxOpenFiles: 1000000
 maxPods: 110
 nodeLeaseDurationSeconds: 40
+nodeStatusMaxImages: 50
 nodeStatusReportFrequency: 5m0s
 nodeStatusUpdateFrequency: 10s
 oomScoreAdj: -999

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

@@ -52,6 +52,7 @@ makeIPTablesUtilChains: true
 maxOpenFiles: 1000000
 maxPods: 110
 nodeLeaseDurationSeconds: 40
+nodeStatusMaxImages: 50
 nodeStatusReportFrequency: 5m0s
 nodeStatusUpdateFrequency: 10s
 oomScoreAdj: -999

pkg/kubelet/apis/config/types.go

@@ -251,6 +251,8 @@ type KubeletConfiguration struct {
 	CPUCFSQuotaPeriod metav1.Duration
 	// maxOpenFiles is Number of files that can be opened by Kubelet process.
 	MaxOpenFiles int64
+	// nodeStatusMaxImages caps the number of images reported in Node.Status.Images.
+	NodeStatusMaxImages int32
 	// contentType is contentType of requests sent to apiserver.
 	ContentType string
 	// kubeAPIQPS is the QPS to use while talking with kubernetes apiserver

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

@@ -176,6 +176,9 @@ func SetDefaults_KubeletConfiguration(obj *kubeletconfigv1beta1.KubeletConfigura
 	if obj.CPUCFSQuotaPeriod == nil {
 		obj.CPUCFSQuotaPeriod = &metav1.Duration{Duration: 100 * time.Millisecond}
 	}
+	if obj.NodeStatusMaxImages == nil {
+		obj.NodeStatusMaxImages = utilpointer.Int32Ptr(50)
+	}
 	if obj.MaxOpenFiles == 0 {
 		obj.MaxOpenFiles = 1000000
 	}

pkg/kubelet/apis/config/v1beta1/zz_generated.conversion.go

@@ -287,6 +287,9 @@ func autoConvert_v1beta1_KubeletConfiguration_To_config_KubeletConfiguration(in
 	if err := v1.Convert_Pointer_v1_Duration_To_v1_Duration(&in.CPUCFSQuotaPeriod, &out.CPUCFSQuotaPeriod, s); err != nil {
 		return err
 	}
+	if err := v1.Convert_Pointer_int32_To_int32(&in.NodeStatusMaxImages, &out.NodeStatusMaxImages, s); err != nil {
+		return err
+	}
 	out.MaxOpenFiles = in.MaxOpenFiles
 	out.ContentType = in.ContentType
 	if err := v1.Convert_Pointer_int32_To_int32(&in.KubeAPIQPS, &out.KubeAPIQPS, s); err != nil {
@@ -425,6 +428,9 @@ func autoConvert_config_KubeletConfiguration_To_v1beta1_KubeletConfiguration(in
 		return err
 	}
 	out.MaxOpenFiles = in.MaxOpenFiles
+	if err := v1.Convert_int32_To_Pointer_int32(&in.NodeStatusMaxImages, &out.NodeStatusMaxImages, s); err != nil {
+		return err
+	}
 	out.ContentType = in.ContentType
 	if err := v1.Convert_int32_To_Pointer_int32(&in.KubeAPIQPS, &out.KubeAPIQPS, s); err != nil {
 		return err

pkg/kubelet/apis/config/validation/validation.go

@@ -83,6 +83,9 @@ func ValidateKubeletConfiguration(kc *kubeletconfig.KubeletConfiguration) error
 	if kc.KubeAPIQPS < 0 {
 		allErrors = append(allErrors, fmt.Errorf("invalid configuration: KubeAPIQPS (--kube-api-qps) %v must not be a negative number", kc.KubeAPIQPS))
 	}
+	if kc.NodeStatusMaxImages < -1 {
+		allErrors = append(allErrors, fmt.Errorf("invalid configuration: NodeStatusMaxImages (--node-status-max-images) must be -1 or greater"))
+	}
 	if kc.MaxOpenFiles < 0 {
 		allErrors = append(allErrors, fmt.Errorf("invalid configuration: MaxOpenFiles (--max-open-files) %v must not be a negative number", kc.MaxOpenFiles))
 	}

staging/src/k8s.io/kubelet/config/v1beta1/types.go

@@ -509,6 +509,13 @@ type KubeletConfiguration struct {
 	// Default: "100ms"
 	// +optional
 	CPUCFSQuotaPeriod *metav1.Duration `json:"cpuCFSQuotaPeriod,omitempty"`
+	// nodeStatusMaxImages caps the number of images reported in Node.Status.Images.
+	// Note: If -1 is specified, no cap will be applied. If 0 is specified, no image is returned.
+	// Dynamic Kubelet Config (beta): If dynamically updating this field, consider that
+	// different values can be reported on node status.
+	// Default: 50
+	// +optional
+	NodeStatusMaxImages *int32 `json:"nodeStatusMaxImages,omitempty"`
 	// maxOpenFiles is Number of files that can be opened by Kubelet process.
 	// Dynamic Kubelet Config (beta): If dynamically updating this field, consider that
 	// it may impact the ability of the Kubelet to interact with the node's filesystem.

staging/src/k8s.io/kubelet/config/v1beta1/zz_generated.deepcopy.go

@@ -185,6 +185,11 @@ func (in *KubeletConfiguration) DeepCopyInto(out *KubeletConfiguration) {
 		*out = new(v1.Duration)
 		**out = **in
 	}
+	if in.NodeStatusMaxImages != nil {
+		in, out := &in.NodeStatusMaxImages, &out.NodeStatusMaxImages
+		*out = new(int32)
+		**out = **in
+	}
 	if in.KubeAPIQPS != nil {
 		in, out := &in.KubeAPIQPS, &out.KubeAPIQPS
 		*out = new(int32)