From 560394da38422cf106917b7addc3fa828e746b6b Mon Sep 17 00:00:00 2001
From: Marek Siarkowicz <serathius@users.noreply.github.com>
Date: Wed, 18 Nov 2020 00:14:20 +0100
Subject: [PATCH] Use protobuf for kubectl top

---
 .../k8s.io/kubectl/pkg/cmd/top/top_node.go    | 17 ++++++++++----
 .../src/k8s.io/kubectl/pkg/cmd/top/top_pod.go | 22 +++++++++++++------
 2 files changed, 28 insertions(+), 11 deletions(-)

diff --git a/staging/src/k8s.io/kubectl/pkg/cmd/top/top_node.go b/staging/src/k8s.io/kubectl/pkg/cmd/top/top_node.go
index 1a7386623cd..8f47fd08f9f 100644
--- a/staging/src/k8s.io/kubectl/pkg/cmd/top/top_node.go
+++ b/staging/src/k8s.io/kubectl/pkg/cmd/top/top_node.go
@@ -27,6 +27,7 @@ import (
 	"k8s.io/cli-runtime/pkg/genericclioptions"
 	"k8s.io/client-go/discovery"
 	corev1client "k8s.io/client-go/kubernetes/typed/core/v1"
+	"k8s.io/klog/v2"
 	cmdutil "k8s.io/kubectl/pkg/cmd/util"
 	"k8s.io/kubectl/pkg/metricsutil"
 	"k8s.io/kubectl/pkg/util/i18n"
@@ -38,10 +39,12 @@ import (
 
 // TopNodeOptions contains all the options for running the top-node cli command.
 type TopNodeOptions struct {
-	ResourceName    string
-	Selector        string
-	SortBy          string
-	NoHeaders       bool
+	ResourceName       string
+	Selector           string
+	SortBy             string
+	NoHeaders          bool
+	UseProtocolBuffers bool
+
 	NodeClient      corev1client.CoreV1Interface
 	Printer         *metricsutil.TopCmdPrinter
 	DiscoveryClient discovery.DiscoveryInterface
@@ -87,6 +90,7 @@ func NewCmdTopNode(f cmdutil.Factory, o *TopNodeOptions, streams genericclioptio
 	cmd.Flags().StringVarP(&o.Selector, "selector", "l", o.Selector, "Selector (label query) to filter on, supports '=', '==', and '!='.(e.g. -l key1=value1,key2=value2)")
 	cmd.Flags().StringVar(&o.SortBy, "sort-by", o.Selector, "If non-empty, sort nodes list using specified field. The field can be either 'cpu' or 'memory'.")
 	cmd.Flags().BoolVar(&o.NoHeaders, "no-headers", o.NoHeaders, "If present, print output without headers")
+	cmd.Flags().BoolVar(&o.UseProtocolBuffers, "use-protocol-buffers", o.UseProtocolBuffers, "If present, protocol-buffers will be used to request metrics.")
 
 	return cmd
 }
@@ -109,6 +113,11 @@ func (o *TopNodeOptions) Complete(f cmdutil.Factory, cmd *cobra.Command, args []
 	if err != nil {
 		return err
 	}
+	if o.UseProtocolBuffers {
+		config.ContentType = "application/vnd.kubernetes.protobuf"
+	} else {
+		klog.Warning("Using json format to get metrics. Next release will switch to protocol-buffers, switch early by passing --use-protocol-buffers flag")
+	}
 	o.MetricsClient, err = metricsclientset.NewForConfig(config)
 	if err != nil {
 		return err
diff --git a/staging/src/k8s.io/kubectl/pkg/cmd/top/top_pod.go b/staging/src/k8s.io/kubectl/pkg/cmd/top/top_pod.go
index 3b9bd1296da..9921fefe2d6 100644
--- a/staging/src/k8s.io/kubectl/pkg/cmd/top/top_pod.go
+++ b/staging/src/k8s.io/kubectl/pkg/cmd/top/top_pod.go
@@ -41,13 +41,15 @@ import (
 )
 
 type TopPodOptions struct {
-	ResourceName    string
-	Namespace       string
-	Selector        string
-	SortBy          string
-	AllNamespaces   bool
-	PrintContainers bool
-	NoHeaders       bool
+	ResourceName       string
+	Namespace          string
+	Selector           string
+	SortBy             string
+	AllNamespaces      bool
+	PrintContainers    bool
+	NoHeaders          bool
+	UseProtocolBuffers bool
+
 	PodClient       corev1client.PodsGetter
 	Printer         *metricsutil.TopCmdPrinter
 	DiscoveryClient discovery.DiscoveryInterface
@@ -106,6 +108,7 @@ func NewCmdTopPod(f cmdutil.Factory, o *TopPodOptions, streams genericclioptions
 	cmd.Flags().BoolVar(&o.PrintContainers, "containers", o.PrintContainers, "If present, print usage of containers within a pod.")
 	cmd.Flags().BoolVarP(&o.AllNamespaces, "all-namespaces", "A", o.AllNamespaces, "If present, list the requested object(s) across all namespaces. Namespace in current context is ignored even if specified with --namespace.")
 	cmd.Flags().BoolVar(&o.NoHeaders, "no-headers", o.NoHeaders, "If present, print output without headers.")
+	cmd.Flags().BoolVar(&o.UseProtocolBuffers, "use-protocol-buffers", o.UseProtocolBuffers, "If present, protocol-buffers will be used to request metrics.")
 	return cmd
 }
 
@@ -131,6 +134,11 @@ func (o *TopPodOptions) Complete(f cmdutil.Factory, cmd *cobra.Command, args []s
 	if err != nil {
 		return err
 	}
+	if o.UseProtocolBuffers {
+		config.ContentType = "application/vnd.kubernetes.protobuf"
+	} else {
+		klog.Warning("Using json format to get metrics. Next release will switch to protocol-buffers, switch early by passing --use-protocol-buffers flag")
+	}
 	o.MetricsClient, err = metricsclientset.NewForConfig(config)
 	if err != nil {
 		return err