Pass IsOpenshiftSupported to Webhook instead of global var

Global variable should be avoided and encapsulating the value in a better way was needed by using an initalizaion function, NewOpenshiftValidator, and modify SetupWebhookWithManager input

api/v1beta1/nodemaintenance_webhook.go

@@ -32,8 +32,6 @@ import (
 	logf "sigs.k8s.io/controller-runtime/pkg/log"
 	"sigs.k8s.io/controller-runtime/pkg/webhook"
 	"sigs.k8s.io/controller-runtime/pkg/webhook/admission"
-
-	"github.com/medik8s/node-maintenance-operator/pkg/utils"
 )
 
 const (
@@ -57,15 +55,17 @@ var nodemaintenancelog = logf.Log.WithName("nodemaintenance-resource")
 // NodeMaintenanceValidator validates NodeMaintenance resources. Needed because we need a client for validation
 // +k8s:deepcopy-gen=false
 type NodeMaintenanceValidator struct {
-	client client.Client
+	client      client.Client
+	isOpenShift bool
 }
 
 var validator *NodeMaintenanceValidator
 
-func (r *NodeMaintenance) SetupWebhookWithManager(mgr ctrl.Manager) error {
+func (r *NodeMaintenance) SetupWebhookWithManager(isOpenShift bool, mgr ctrl.Manager) error {
 	// init the validator!
 	validator = &NodeMaintenanceValidator{
-		client: mgr.GetClient(),
+		client:      mgr.GetClient(),
+		isOpenShift: isOpenShift,
 	}
 
 	return ctrl.NewWebhookManagedBy(mgr).
@@ -165,7 +165,7 @@ func (v *NodeMaintenanceValidator) validateNoNodeMaintenanceExists(nodeName stri
 }
 
 func (v *NodeMaintenanceValidator) validateControlPlaneQuorum(nodeName string) error {
-	if !utils.IsOpenshiftSupported {
+	if !v.isOpenShift {
 		// etcd quorum PDB is only installed in OpenShift
 		nodemaintenancelog.Info("Cluster does not have etcd quorum PDB, thus we can't asses control-plane quorum violation")
 		return nil

api/v1beta1/nodemaintenance_webhook_test.go

@@ -11,8 +11,6 @@ import (
 	policyv1 "k8s.io/api/policy/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"sigs.k8s.io/controller-runtime/pkg/client"
-
-	"github.com/medik8s/node-maintenance-operator/pkg/utils"
 )
 
 var _ = Describe("NodeMaintenance Validation", func() {
@@ -93,10 +91,6 @@ var _ = Describe("NodeMaintenance Validation", func() {
 				node = getTestNode(existingNodeName, true)
 				err := k8sClient.Create(context.Background(), node)
 				Expect(err).ToNot(HaveOccurred())
-				// mock IsOpenshiftSupported value and set it true for the quorum violation check
-				orgValue := utils.IsOpenshiftSupported
-				utils.IsOpenshiftSupported = true
-				DeferCleanup(func() { utils.IsOpenshiftSupported = orgValue })
 			})
 
 			AfterEach(func() {
@@ -160,7 +154,6 @@ var _ = Describe("NodeMaintenance Validation", func() {
 					nm := getTestNMO(existingNodeName)
 					Expect(nm.ValidateCreate()).Error().NotTo(HaveOccurred())
 				})
-
 			})
 
 			Context("without etcd quorum guard PDB", func() {

api/v1beta1/webhook_suite_test.go

@@ -42,16 +42,20 @@ import (
 	"sigs.k8s.io/controller-runtime/pkg/log/zap"
 	metricsServer "sigs.k8s.io/controller-runtime/pkg/metrics/server"
 	"sigs.k8s.io/controller-runtime/pkg/webhook"
+
+	"github.com/medik8s/node-maintenance-operator/pkg/utils"
 )
 
 // These tests use Ginkgo (BDD-style Go testing framework). Refer to
 // http://onsi.github.io/ginkgo/ to learn more about Ginkgo.
 
-var cfg *rest.Config
-var k8sClient client.Client
-var testEnv *envtest.Environment
-var ctx context.Context
-var cancel context.CancelFunc
+var (
+	cfg       *rest.Config
+	k8sClient client.Client
+	testEnv   *envtest.Environment
+	ctx       context.Context
+	cancel    context.CancelFunc
+)
 
 func TestAPIs(t *testing.T) {
 	RegisterFailHandler(Fail)
@@ -97,6 +101,10 @@ var _ = BeforeSuite(func() {
 	Expect(err).NotTo(HaveOccurred())
 	Expect(k8sClient).NotTo(BeNil())
 
+	openshiftCheck, err := utils.NewOpenshiftValidator(cfg)
+	Expect(err).NotTo(HaveOccurred(), "failed to check if we run on Openshift")
+	Expect(openshiftCheck.IsOpenshiftSupported()).To(BeFalse())
+
 	// start webhook server using Manager
 	webhookInstallOptions := &testEnv.WebhookInstallOptions
 	mgr, err := ctrl.NewManager(cfg, ctrl.Options{
@@ -110,7 +118,7 @@ var _ = BeforeSuite(func() {
 	})
 	Expect(err).NotTo(HaveOccurred())
 
-	err = (&NodeMaintenance{}).SetupWebhookWithManager(mgr)
+	err = (&NodeMaintenance{}).SetupWebhookWithManager(true, mgr)
 	Expect(err).NotTo(HaveOccurred())
 
 	//+kubebuilder:scaffold:webhook

main.go

@@ -112,11 +112,15 @@ func main() {
 		os.Exit(1)
 	}
 
-	if err := utils.ValidateIsOpenshift(mgr.GetConfig()); err != nil {
+	openshiftCheck,err := utils.NewOpenshiftValidator(mgr.GetConfig())
+	if err != nil {
 		setupLog.Error(err, "failed to check if we run on Openshift")
 		os.Exit(1)
 	}
-	setupLog.Info("NMO was installed on Openshift cluster")
+	isOpenShift := openshiftCheck.IsOpenshiftSupported()
+	if isOpenShift{
+		setupLog.Info("NMO was installed on Openshift cluster")
+	}
 
 
 	if err = (&controllers.NodeMaintenanceReconciler{
@@ -127,7 +131,7 @@ func main() {
 		setupLog.Error(err, "unable to create controller", "controller", "NodeMaintenance")
 		os.Exit(1)
 	}
-	if err = (&nodemaintenancev1beta1.NodeMaintenance{}).SetupWebhookWithManager(mgr); err != nil {
+	if err = (&nodemaintenancev1beta1.NodeMaintenance{}).SetupWebhookWithManager(isOpenShift, mgr); err != nil {
 		setupLog.Error(err, "unable to create webhook", "webhook", "NodeMaintenance")
 		os.Exit(1)
 	}

pkg/utils/validation.go

@@ -6,11 +6,26 @@ import (
 	"k8s.io/client-go/rest"
 )
 
-// IsOpenshiftSupported will be set to true in case the operator was installed on OpenShift cluster
-var	IsOpenshiftSupported bool
+type OpenshiftValidator struct {
+// isOpenshiftSupported will be set to true in case the operator was installed on OpenShift cluster
+ isOpenshiftSupported bool
+}
 
-// ValidateIsOpenshift returns true if the cluster has the openshift config group
-func ValidateIsOpenshift(config *rest.Config) error {
+// NewOpenshiftValidator initialization function for OpenshiftValidator
+func NewOpenshiftValidator(config *rest.Config) (*OpenshiftValidator, error) {
+	v := &OpenshiftValidator{}
+	if err := v.validateIsOpenshift(config); err != nil {
+		return nil, err
+	}
+	return v, nil
+}
+
+// IsOpenshiftSupported returns whether the cluster supports OpenShift
+func (v *OpenshiftValidator) IsOpenshiftSupported() bool {
+	return v.isOpenshiftSupported
+}
+// validateIsOpenshift returns true if the cluster has the openshift config group
+func (v *OpenshiftValidator) validateIsOpenshift(config *rest.Config) error {
 	dc, err := discovery.NewDiscoveryClientForConfig(config)
 	if err != nil {
 		return err
@@ -19,12 +34,12 @@ func ValidateIsOpenshift(config *rest.Config) error {
 	if err != nil {
 		return err
 	}
-	
+
 	kind := schema.GroupVersionKind{Group: "config.openshift.io", Version: "v1", Kind: "ClusterVersion"}
 	for _, apiGroup := range apiGroups.Groups {
 		for _, supportedVersion := range apiGroup.Versions {
 			if supportedVersion.GroupVersion == kind.GroupVersion().String() {
-				IsOpenshiftSupported = true
+				v.isOpenshiftSupported = true
 				return nil
 			}
 		}