Merge pull request kubernetes#85282 from serathius/flag-kubelet

Add show-hidden-metrics-for-version to kubelet

Author: k8s-ci-robot

cmd/kubelet/app/BUILD

@@ -139,6 +139,7 @@ go_library(
         "//staging/src/k8s.io/cloud-provider:go_default_library",
         "//staging/src/k8s.io/component-base/cli/flag:go_default_library",
         "//staging/src/k8s.io/component-base/featuregate:go_default_library",
+        "//staging/src/k8s.io/component-base/metrics:go_default_library",
         "//staging/src/k8s.io/component-base/version:go_default_library",
         "//staging/src/k8s.io/component-base/version/verflag:go_default_library",
         "//staging/src/k8s.io/csi-translation-lib/plugins:go_default_library",

cmd/kubelet/app/server.go

@@ -62,6 +62,7 @@ import (
 	cloudprovider "k8s.io/cloud-provider"
 	cliflag "k8s.io/component-base/cli/flag"
 	"k8s.io/component-base/featuregate"
+	"k8s.io/component-base/metrics"
 	"k8s.io/component-base/version"
 	"k8s.io/component-base/version/verflag"
 	kubeletconfigv1beta1 "k8s.io/kubelet/config/v1beta1"
@@ -509,6 +510,10 @@ func run(s *options.KubeletServer, kubeDeps *kubelet.Dependencies, featureGate f
 		klog.Errorf("unable to register KubeletConfiguration with configz, error: %v", err)
 	}
 
+	if len(s.ShowHiddenMetricsForVersion) > 0 {
+		metrics.SetShowHidden()
+	}
+
 	// About to get clients and such, detect standaloneMode
 	standaloneMode := true
 	if len(s.KubeConfig) > 0 {

pkg/kubelet/apis/config/helpers_test.go

@@ -215,6 +215,7 @@ var (
 		"ReservedSystemCPUs",
 		"RuntimeRequestTimeout.Duration",
 		"SerializeImagePulls",
+		"ShowHiddenMetricsForVersion",
 		"StreamingConnectionIdleTimeout.Duration",
 		"SyncFrequency.Duration",
 		"SystemCgroups",

pkg/kubelet/apis/config/types.go

@@ -335,6 +335,12 @@ type KubeletConfiguration struct {
 	// This provide a "static" CPU list rather than the "dynamic" list by system-reserved and kube-reserved.
 	// This option overwrites CPUs provided by system-reserved and kube-reserved.
 	ReservedSystemCPUs string
+	// The previous version for which you want to show hidden metrics.
+	// Only the previous minor version is meaningful, other values will not be allowed.
+	// The format is <major>.<minor>, e.g.: '1.16'.
+	// The purpose of this format is make sure you have the opportunity to notice if the next release hides additional metrics,
+	// rather than being surprised when they are permanently removed in the release after that.
+	ShowHiddenMetricsForVersion string
 }
 
 // KubeletAuthorizationMode denotes the authorization mode for the kubelet

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

@@ -22,6 +22,7 @@ go_library(
         "//staging/src/k8s.io/apimachinery/pkg/util/errors:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/util/validation:go_default_library",
         "//staging/src/k8s.io/apiserver/pkg/util/feature:go_default_library",
+        "//staging/src/k8s.io/component-base/metrics:go_default_library",
     ],
 )
 

pkg/kubelet/apis/config/validation/BUILD

@@ -23,6 +23,7 @@ import (
 	utilerrors "k8s.io/apimachinery/pkg/util/errors"
 	utilvalidation "k8s.io/apimachinery/pkg/util/validation"
 	utilfeature "k8s.io/apiserver/pkg/util/feature"
+	"k8s.io/component-base/metrics"
 	"k8s.io/kubernetes/pkg/features"
 	kubeletconfig "k8s.io/kubernetes/pkg/kubelet/apis/config"
 	"k8s.io/kubernetes/pkg/kubelet/cm/cpuset"
@@ -156,5 +157,6 @@ func ValidateKubeletConfiguration(kc *kubeletconfig.KubeletConfiguration) error
 	if err := validateKubeletOSConfiguration(kc); err != nil {
 		allErrors = append(allErrors, err)
 	}
+	allErrors = append(allErrors, metrics.ValidateShowHiddenMetricsVersion(kc.ShowHiddenMetricsForVersion)...)
 	return utilerrors.NewAggregate(allErrors)
 }

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

@@ -714,6 +714,14 @@ type KubeletConfiguration struct {
 	// This provide a "static" CPU list rather than the "dynamic" list by system-reserved and kube-reserved.
 	// This option overwrites CPUs provided by system-reserved and kube-reserved.
 	ReservedSystemCPUs string `json:"reservedSystemCPUs,omitempty"`
+	// The previous version for which you want to show hidden metrics.
+	// Only the previous minor version is meaningful, other values will not be allowed.
+	// The format is <major>.<minor>, e.g.: '1.16'.
+	// The purpose of this format is make sure you have the opportunity to notice if the next release hides additional metrics,
+	// rather than being surprised when they are permanently removed in the release after that.
+	// Default: ""
+	// +optional
+	ShowHiddenMetricsForVersion string `json:"showHiddenMetricsForVersion,omitempty"`
 	// This flag helps kubelet identify absolute name of top level cgroup used to enforce `SystemReserved` compute resource reservation for OS system daemons.
 	// Refer to [Node Allocatable](https://git.k8s.io/community/contributors/design-proposals/node/node-allocatable.md) doc for more information.
 	// Dynamic Kubelet Config (beta): This field should not be updated without a full node