From e3f3da5e795960508089aed08fe7fd9bec0a6db2 Mon Sep 17 00:00:00 2001
From: Maciej Szulik <soltysh@gmail.com>
Date: Thu, 8 May 2025 14:09:17 +0200
Subject: [PATCH] Swap KUBECTL_COMMAND_HEADERS to use the proper feature gate
 mechanism

Signed-off-by: Maciej Szulik <soltysh@gmail.com>
---
 staging/src/k8s.io/kubectl/pkg/cmd/cmd.go          | 11 +++--------
 staging/src/k8s.io/kubectl/pkg/cmd/cmd_test.go     |  7 ++-----
 staging/src/k8s.io/kubectl/pkg/cmd/util/helpers.go |  1 +
 test/cmd/results.sh                                |  5 +++++
 4 files changed, 11 insertions(+), 13 deletions(-)

diff --git a/staging/src/k8s.io/kubectl/pkg/cmd/cmd.go b/staging/src/k8s.io/kubectl/pkg/cmd/cmd.go
index 42a2c21923d..bba80472166 100644
--- a/staging/src/k8s.io/kubectl/pkg/cmd/cmd.go
+++ b/staging/src/k8s.io/kubectl/pkg/cmd/cmd.go
@@ -83,8 +83,6 @@ import (
 	"k8s.io/kubectl/pkg/cmd/kustomize"
 )
 
-const kubectlCmdHeaders = "KUBECTL_COMMAND_HEADERS"
-
 type KubectlOptions struct {
 	PluginHandler PluginHandler
 	Arguments     []string
@@ -522,12 +520,9 @@ func NewKubectlCommand(o KubectlOptions) *cobra.Command {
 //
 //	https://github.com/kubernetes/enhancements/tree/master/keps/sig-cli/859-kubectl-headers
 func addCmdHeaderHooks(cmds *cobra.Command, kubeConfigFlags *genericclioptions.ConfigFlags) {
-	// If the feature gate env var is set to "false", then do no add kubectl command headers.
-	if value, exists := os.LookupEnv(kubectlCmdHeaders); exists {
-		if value == "false" || value == "0" {
-			klog.V(5).Infoln("kubectl command headers turned off")
-			return
-		}
+	if cmdutil.CmdHeaders.IsDisabled() {
+		klog.V(5).Infoln("kubectl command headers turned off")
+		return
 	}
 	klog.V(5).Infoln("kubectl command headers turned on")
 	crt := &genericclioptions.CommandHeaderRoundTripper{}
diff --git a/staging/src/k8s.io/kubectl/pkg/cmd/cmd_test.go b/staging/src/k8s.io/kubectl/pkg/cmd/cmd_test.go
index 633bc242eb5..f624d5f8fc4 100644
--- a/staging/src/k8s.io/kubectl/pkg/cmd/cmd_test.go
+++ b/staging/src/k8s.io/kubectl/pkg/cmd/cmd_test.go
@@ -29,6 +29,7 @@ import (
 	"k8s.io/cli-runtime/pkg/genericclioptions"
 	"k8s.io/cli-runtime/pkg/genericiooptions"
 	"k8s.io/kubectl/pkg/cmd/plugin"
+	cmdutil "k8s.io/kubectl/pkg/cmd/util"
 )
 
 func TestNormalizationFuncGlobalExistence(t *testing.T) {
@@ -381,10 +382,6 @@ func TestKubectlCommandHeadersHooks(t *testing.T) {
 			envVar:    "false",
 			addsHooks: false,
 		},
-		"zero env var value; hooks NOT added": {
-			envVar:    "0",
-			addsHooks: false,
-		},
 	}
 
 	for name, testCase := range tests {
@@ -394,7 +391,7 @@ func TestKubectlCommandHeadersHooks(t *testing.T) {
 			if kubeConfigFlags.WrapConfigFn != nil {
 				t.Fatal("expected initial nil WrapConfigFn")
 			}
-			t.Setenv(kubectlCmdHeaders, testCase.envVar)
+			t.Setenv(string(cmdutil.CmdHeaders), testCase.envVar)
 			addCmdHeaderHooks(cmds, kubeConfigFlags)
 			// Valdidate whether the hooks were added.
 			if testCase.addsHooks && kubeConfigFlags.WrapConfigFn == nil {
diff --git a/staging/src/k8s.io/kubectl/pkg/cmd/util/helpers.go b/staging/src/k8s.io/kubectl/pkg/cmd/util/helpers.go
index 083018c6f06..e978841cda6 100644
--- a/staging/src/k8s.io/kubectl/pkg/cmd/util/helpers.go
+++ b/staging/src/k8s.io/kubectl/pkg/cmd/util/helpers.go
@@ -427,6 +427,7 @@ type FeatureGate string
 const (
 	ApplySet                FeatureGate = "KUBECTL_APPLYSET"
 	OpenAPIV3Patch          FeatureGate = "KUBECTL_OPENAPIV3_PATCH"
+	CmdHeaders FeatureGate = "KUBECTL_COMMAND_HEADERS"
 	RemoteCommandWebsockets FeatureGate = "KUBECTL_REMOTE_COMMAND_WEBSOCKETS"
 	PortForwardWebsockets   FeatureGate = "KUBECTL_PORT_FORWARD_WEBSOCKETS"
 	KubeRC                  FeatureGate = "KUBECTL_KUBERC"
diff --git a/test/cmd/results.sh b/test/cmd/results.sh
index a34253f20c2..498d058138f 100644
--- a/test/cmd/results.sh
+++ b/test/cmd/results.sh
@@ -53,6 +53,11 @@ Error from server (NotFound): pods "no-such-pod" not found
 EOF
   kube::test::results::diff "${TEMP}/actual_stdout" "${TEMP}/actual_stderr" "$res" "${TEMP}/empty" "${TEMP}/expected_stderr" 1 "kubectl get pod/no-such-pod"
 
+  output_message=$(kubectl get namespace kube-system 2>&1 "${kube_flags[@]:?}")
+  kube::test::if_has_not_string "${output_message}" "command headers turned on"
+  output_message=$(kubectl get namespace kube-system 2>&1 "${kube_flags[@]:?}" -v=5)
+  kube::test::if_has_string "${output_message}" "command headers turned on"
+
   set +o nounset
   set +o errexit
 }