From 1e0a2657b2fea581af01239ea2ba767bc745f7aa Mon Sep 17 00:00:00 2001
From: Saurabh Parekh <sjparekh@amazon.com>
Date: Tue, 5 Mar 2024 00:38:00 -0800
Subject: [PATCH] Add feature flag to disable apiserver extra args validation

---
 pkg/api/v1alpha1/cluster.go   | 10 ++++++----
 pkg/features/features.go      | 19 ++++++++++++++-----
 pkg/features/features_test.go |  8 ++++++++
 3 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/pkg/api/v1alpha1/cluster.go b/pkg/api/v1alpha1/cluster.go
index ac4d4b3fc6fba..59468bf4943ce 100644
--- a/pkg/api/v1alpha1/cluster.go
+++ b/pkg/api/v1alpha1/cluster.go
@@ -496,10 +496,12 @@ func validateControlPlaneCertSANs(cfg *Cluster) error {
 }
 
 func validateControlPlaneAPIServerExtraArgs(clusterConfig *Cluster) error {
-	allowedFlags := map[string]string{"service-account-issuer": "", "service-account-jwks-uri": ""}
-	for k := range clusterConfig.Spec.ControlPlaneConfiguration.APIServerExtraArgs {
-		if _, ok := allowedFlags[k]; !ok {
-			return fmt.Errorf("invalid argument in ControlPlaneConfiguration.APIServerExtraArgs (service-account-issuer, service-account-jwks-uri): %v", k)
+	if !features.IsActive(features.ApiServerExtraArgsValidationDisabled()) {
+		allowedFlags := map[string]string{"service-account-issuer": "", "service-account-jwks-uri": ""}
+		for k := range clusterConfig.Spec.ControlPlaneConfiguration.APIServerExtraArgs {
+			if _, ok := allowedFlags[k]; !ok {
+				return fmt.Errorf("invalid argument in ControlPlaneConfiguration.APIServerExtraArgs (service-account-issuer, service-account-jwks-uri): %v", k)
+			}
 		}
 	}
 	return nil
diff --git a/pkg/features/features.go b/pkg/features/features.go
index 62e936d074825..e12e6408bbc1f 100644
--- a/pkg/features/features.go
+++ b/pkg/features/features.go
@@ -2,11 +2,12 @@ package features
 
 // These are environment variables used as flags to enable/disable features.
 const (
-	CloudStackKubeVipDisabledEnvVar = "CLOUDSTACK_KUBE_VIP_DISABLED"
-	CheckpointEnabledEnvVar         = "CHECKPOINT_ENABLED"
-	UseNewWorkflowsEnvVar           = "USE_NEW_WORKFLOWS"
-	UseControllerForCli             = "USE_CONTROLLER_FOR_CLI"
-	VSphereInPlaceEnvVar            = "VSPHERE_IN_PLACE_UPGRADE"
+	CloudStackKubeVipDisabledEnvVar            = "CLOUDSTACK_KUBE_VIP_DISABLED"
+	CheckpointEnabledEnvVar                    = "CHECKPOINT_ENABLED"
+	UseNewWorkflowsEnvVar                      = "USE_NEW_WORKFLOWS"
+	UseControllerForCli                        = "USE_CONTROLLER_FOR_CLI"
+	VSphereInPlaceEnvVar                       = "VSPHERE_IN_PLACE_UPGRADE"
+	ApiServerExtraArgsValidationDisabledEnvVar = "APISERVER_EXTRA_ARGS_VALIDATION_DISABLED"
 )
 
 func FeedGates(featureGates []string) {
@@ -63,3 +64,11 @@ func VSphereInPlaceUpgradeEnabled() Feature {
 		IsActive: globalFeatures.isActiveForEnvVar(VSphereInPlaceEnvVar),
 	}
 }
+
+// ApiServerExtraArgsValidationDisabled is the feature flag for disabling the API server extra args validation.
+func ApiServerExtraArgsValidationDisabled() Feature {
+	return Feature{
+		Name:     "Disable API server extra args validation",
+		IsActive: globalFeatures.isActiveForEnvVar(ApiServerExtraArgsValidationDisabledEnvVar),
+	}
+}
diff --git a/pkg/features/features_test.go b/pkg/features/features_test.go
index 8e65b586af511..35a6cd46aa8c4 100644
--- a/pkg/features/features_test.go
+++ b/pkg/features/features_test.go
@@ -93,3 +93,11 @@ func TestVSphereInPlaceUpgradeEnabledFeatureFlag(t *testing.T) {
 	g.Expect(os.Setenv(VSphereInPlaceEnvVar, "true")).To(Succeed())
 	g.Expect(IsActive(VSphereInPlaceUpgradeEnabled())).To(BeTrue())
 }
+
+func TestApiServerExtraArgsValidationDisabledFeatureFlag(t *testing.T) {
+	g := NewWithT(t)
+	setupContext(t)
+
+	g.Expect(os.Setenv(ApiServerExtraArgsValidationDisabledEnvVar, "true")).To(Succeed())
+	g.Expect(IsActive(ApiServerExtraArgsValidationDisabled())).To(BeTrue())
+}