Kubelet manager configuration

cmd/kubeadm/app/util/config/testdata/conversion/master/internal.yaml

@@ -96,6 +96,7 @@ KubeletConfiguration:
     clusterDNS:
     - 10.96.0.10
     clusterDomain: cluster.local
+    configMapAndSecretChangeDetectionStrategy: Watch
     containerLogMaxFiles: 5
     containerLogMaxSize: 10Mi
     contentType: application/vnd.kubernetes.protobuf

cmd/kubeadm/app/util/config/testdata/conversion/master/v1alpha1.yaml

@@ -85,6 +85,7 @@ kubeletConfiguration:
     clusterDNS:
     - 10.96.0.10
     clusterDomain: cluster.local
+    configMapAndSecretChangeDetectionStrategy: Watch
     containerLogMaxFiles: 5
     containerLogMaxSize: 10Mi
     contentType: application/vnd.kubernetes.protobuf

cmd/kubeadm/app/util/config/testdata/conversion/master/v1alpha1_without_TypeMeta.yaml

@@ -82,6 +82,7 @@ kubeletConfiguration:
     clusterDNS:
     - 10.96.0.10
     clusterDomain: cluster.local
+    configMapAndSecretChangeDetectionStrategy: Watch
     containerLogMaxFiles: 5
     containerLogMaxSize: 10Mi
     contentType: application/vnd.kubernetes.protobuf

cmd/kubeadm/app/util/config/testdata/conversion/master/v1alpha2.yaml

@@ -86,6 +86,7 @@ kubeletConfiguration:
     clusterDNS:
     - 10.96.0.10
     clusterDomain: cluster.local
+    configMapAndSecretChangeDetectionStrategy: Watch
     containerLogMaxFiles: 5
     containerLogMaxSize: 10Mi
     contentType: application/vnd.kubernetes.protobuf

cmd/kubeadm/app/util/config/testdata/defaulting/master/defaulted.yaml

@@ -81,6 +81,7 @@ kubeletConfiguration:
     clusterDNS:
     - 10.192.0.10
     clusterDomain: cluster.global
+    configMapAndSecretChangeDetectionStrategy: Watch
     containerLogMaxFiles: 5
     containerLogMaxSize: 10Mi
     contentType: application/vnd.kubernetes.protobuf

pkg/kubelet/apis/kubeletconfig/helpers_test.go

@@ -153,6 +153,7 @@ var (
 		"CgroupsPerQOS",
 		"ClusterDNS[*]",
 		"ClusterDomain",
+		"ConfigMapAndSecretChangeDetectionStrategy",
 		"ContainerLogMaxFiles",
 		"ContainerLogMaxSize",
 		"ContentType",

pkg/kubelet/apis/kubeletconfig/types.go

@@ -39,6 +39,23 @@ const (
 	HairpinNone = "none"
 )
 
+// ResourceChangeDetectionStrategy denotes a mode in which internal
+// managers (secret, configmap) are discovering object changes.
+type ResourceChangeDetectionStrategy string
+
+// Enum settings for different strategies of kubelet managers.
+const (
+	// GetChangeDetectionStrategy is a mode in which kubelet fetches
+	// necessary objects directly from apiserver.
+	GetChangeDetectionStrategy ResourceChangeDetectionStrategy = "Get"
+	// TTLCacheChangeDetectionStrategy is a mode in which kubelet uses
+	// ttl cache for object directly fetched from apiserver.
+	TTLCacheChangeDetectionStrategy ResourceChangeDetectionStrategy = "Cache"
+	// WatchChangeDetectionStrategy is a mode in which kubelet uses
+	// watches to observe changes to objects that are in its interest.
+	WatchChangeDetectionStrategy ResourceChangeDetectionStrategy = "Watch"
+)
+
 // +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
 
 // KubeletConfiguration contains the configuration for the Kubelet
@@ -259,6 +276,8 @@ type KubeletConfiguration struct {
 	ContainerLogMaxSize string
 	// Maximum number of container log files that can be present for a container.
 	ContainerLogMaxFiles int32
+	// ConfigMapAndSecretChangeDetectionStrategy is a mode in which config map and secret managers are running.
+	ConfigMapAndSecretChangeDetectionStrategy ResourceChangeDetectionStrategy
 
 	/* the following fields are meant for Node Allocatable */
 

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

@@ -198,6 +198,9 @@ func SetDefaults_KubeletConfiguration(obj *KubeletConfiguration) {
 	if obj.ContainerLogMaxFiles == nil {
 		obj.ContainerLogMaxFiles = utilpointer.Int32Ptr(5)
 	}
+	if obj.ConfigMapAndSecretChangeDetectionStrategy == "" {
+		obj.ConfigMapAndSecretChangeDetectionStrategy = WatchChangeDetectionStrategy
+	}
 	if obj.EnforceNodeAllocatable == nil {
 		obj.EnforceNodeAllocatable = DefaultNodeAllocatableEnforcement
 	}

pkg/kubelet/apis/kubeletconfig/v1beta1/types.go

@@ -39,6 +39,23 @@ const (
 	HairpinNone = "none"
 )
 
+// ResourceChangeDetectionStrategy denotes a mode in which internal
+// managers (secret, configmap) are discovering object changes.
+type ResourceChangeDetectionStrategy string
+
+// Enum settings for different strategies of kubelet managers.
+const (
+	// GetChangeDetectionStrategy is a mode in which kubelet fetches
+	// necessary objects directly from apiserver.
+	GetChangeDetectionStrategy ResourceChangeDetectionStrategy = "Get"
+	// TTLCacheChangeDetectionStrategy is a mode in which kubelet uses
+	// ttl cache for object directly fetched from apiserver.
+	TTLCacheChangeDetectionStrategy ResourceChangeDetectionStrategy = "Cache"
+	// WatchChangeDetectionStrategy is a mode in which kubelet uses
+	// watches to observe changes to objects that are in its interest.
+	WatchChangeDetectionStrategy ResourceChangeDetectionStrategy = "Watch"
+)
+
 // +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
 
 // KubeletConfiguration contains the configuration for the Kubelet
@@ -612,6 +629,11 @@ type KubeletConfiguration struct {
 	// Default: 5
 	// +optional
 	ContainerLogMaxFiles *int32 `json:"containerLogMaxFiles,omitempty"`
+	// ConfigMapAndSecretChangeDetectionStrategy is a mode in which
+	// config map and secret managers are running.
+	// Default: "Watching"
+	// +optional
+	ConfigMapAndSecretChangeDetectionStrategy ResourceChangeDetectionStrategy `json:"configMapAndSecretChangeDetectionStrategy,omitempty"`
 
 	/* the following fields are meant for Node Allocatable */