Add show hidden flag to kube-proxy

cmd/kube-proxy/app/server.go

@@ -150,6 +150,12 @@ func (o *Options) AddFlags(fs *pflag.FlagSet) {
 	fs.StringVar(&o.master, "master", o.master, "The address of the Kubernetes API server (overrides any value in kubeconfig)")
 	fs.StringVar(&o.hostnameOverride, "hostname-override", o.hostnameOverride, "If non-empty, will use this string as identification instead of the actual hostname.")
 	fs.StringVar(&o.config.IPVS.Scheduler, "ipvs-scheduler", o.config.IPVS.Scheduler, "The ipvs scheduler type when proxy mode is ipvs")
+	fs.StringVar(&o.config.ShowHiddenMetricsForVersion, "show-hidden-metrics-for-version", o.config.ShowHiddenMetricsForVersion,
+		"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.")
 
 	fs.StringSliceVar(&o.config.IPVS.ExcludeCIDRs, "ipvs-exclude-cidrs", o.config.IPVS.ExcludeCIDRs, "A comma-separated list of CIDR's which the ipvs proxier should not touch when cleaning up IPVS rules.")
 	fs.StringSliceVar(&o.config.NodePortAddresses, "nodeport-addresses", o.config.NodePortAddresses,

cmd/kube-proxy/app/server_others.go

@@ -32,6 +32,7 @@ import (
 	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
 	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	"k8s.io/client-go/tools/record"
+	"k8s.io/component-base/metrics"
 	"k8s.io/kubernetes/pkg/features"
 	"k8s.io/kubernetes/pkg/proxy"
 	proxyconfigapi "k8s.io/kubernetes/pkg/proxy/apis/config"
@@ -39,7 +40,7 @@ import (
 	"k8s.io/kubernetes/pkg/proxy/healthcheck"
 	"k8s.io/kubernetes/pkg/proxy/iptables"
 	"k8s.io/kubernetes/pkg/proxy/ipvs"
-	"k8s.io/kubernetes/pkg/proxy/metrics"
+	proxymetrics "k8s.io/kubernetes/pkg/proxy/metrics"
 	"k8s.io/kubernetes/pkg/proxy/userspace"
 	"k8s.io/kubernetes/pkg/util/configz"
 	utilipset "k8s.io/kubernetes/pkg/util/ipset"
@@ -105,6 +106,10 @@ func newProxyServer(
 		}, nil
 	}
 
+	if len(config.ShowHiddenMetricsForVersion) > 0 {
+		metrics.SetShowHidden()
+	}
+
 	client, eventClient, err := createClients(config.ClientConnection, master)
 	if err != nil {
 		return nil, err
@@ -167,7 +172,7 @@ func newProxyServer(
 		if err != nil {
 			return nil, fmt.Errorf("unable to create proxier: %v", err)
 		}
-		metrics.RegisterMetrics()
+		proxymetrics.RegisterMetrics()
 	} else if proxyMode == proxyModeIPVS {
 		klog.V(0).Info("Using ipvs Proxier.")
 		if utilfeature.DefaultFeatureGate.Enabled(features.IPv6DualStack) {
@@ -228,7 +233,7 @@ func newProxyServer(
 		if err != nil {
 			return nil, fmt.Errorf("unable to create proxier: %v", err)
 		}
-		metrics.RegisterMetrics()
+		proxymetrics.RegisterMetrics()
 	} else {
 		klog.V(0).Info("Using userspace Proxier.")
 

cmd/kube-proxy/app/server_windows.go

@@ -32,6 +32,7 @@ import (
 	"k8s.io/apimachinery/pkg/types"
 	utilnet "k8s.io/apimachinery/pkg/util/net"
 	"k8s.io/client-go/tools/record"
+	"k8s.io/component-base/metrics"
 	"k8s.io/kubernetes/pkg/proxy"
 	proxyconfigapi "k8s.io/kubernetes/pkg/proxy/apis/config"
 	proxyconfigscheme "k8s.io/kubernetes/pkg/proxy/apis/config/scheme"
@@ -67,6 +68,10 @@ func newProxyServer(config *proxyconfigapi.KubeProxyConfiguration, cleanupAndExi
 		return &ProxyServer{}, nil
 	}
 
+	if len(config.ShowHiddenMetricsForVersion) > 0 {
+		metrics.SetShowHidden()
+	}
+
 	client, eventClient, err := createClients(config.ClientConnection, master)
 	if err != nil {
 		return nil, err

pkg/proxy/apis/config/types.go

@@ -153,6 +153,8 @@ type KubeProxyConfiguration struct {
 	NodePortAddresses []string
 	// winkernel contains winkernel-related configuration options.
 	Winkernel KubeProxyWinkernelConfiguration
+	// ShowHiddenMetricsForVersion is the version for which you want to show hidden metrics.
+	ShowHiddenMetricsForVersion string
 }
 
 // Currently, three modes of proxy are available in Linux platform: 'userspace' (older, going to be EOL), 'iptables'

pkg/proxy/apis/config/validation/validation.go

@@ -27,6 +27,7 @@ import (
 	"k8s.io/apimachinery/pkg/util/sets"
 	"k8s.io/apimachinery/pkg/util/validation/field"
 	componentbaseconfig "k8s.io/component-base/config"
+	"k8s.io/component-base/metrics"
 	apivalidation "k8s.io/kubernetes/pkg/apis/core/validation"
 	kubefeatures "k8s.io/kubernetes/pkg/features"
 	kubeproxyconfig "k8s.io/kubernetes/pkg/proxy/apis/config"
@@ -87,6 +88,7 @@ func Validate(config *kubeproxyconfig.KubeProxyConfiguration) field.ErrorList {
 	}
 
 	allErrs = append(allErrs, validateKubeProxyNodePortAddress(config.NodePortAddresses, newPath.Child("NodePortAddresses"))...)
+	allErrs = append(allErrs, validateShowHiddenMetricsVersion(config.ShowHiddenMetricsForVersion, newPath.Child("ShowHiddenMetricsForVersion"))...)
 
 	return allErrs
 }
@@ -274,3 +276,13 @@ func validateIPVSExcludeCIDRs(excludeCIDRs []string, fldPath *field.Path) field.
 	}
 	return allErrs
 }
+
+func validateShowHiddenMetricsVersion(version string, fldPath *field.Path) field.ErrorList {
+	allErrs := field.ErrorList{}
+	errs := metrics.ValidateShowHiddenMetricsVersion(version)
+	for _, e := range errs {
+		allErrs = append(allErrs, field.Invalid(fldPath, version, e.Error()))
+	}
+
+	return allErrs
+}

staging/src/k8s.io/kube-proxy/config/v1alpha1/types.go

@@ -149,6 +149,8 @@ type KubeProxyConfiguration struct {
 	NodePortAddresses []string `json:"nodePortAddresses"`
 	// winkernel contains winkernel-related configuration options.
 	Winkernel KubeProxyWinkernelConfiguration `json:"winkernel"`
+	// ShowHiddenMetricsForVersion is the version for which you want to show hidden metrics.
+	ShowHiddenMetricsForVersion string `json:"showHiddenMetricsForVersion"`
 }
 
 // Currently, three modes of proxy are available in Linux platform: 'userspace' (older, going to be EOL), 'iptables'