refactor: add os utils sub package (#3528)

Signed-off-by: Charles-Edouard Brétéché <charled.breteche@gmail.com>

Co-authored-by: shuting <shuting@nirmata.com>

cmd/initContainer/main.go

@@ -127,7 +127,7 @@ func main() {
 			os.Exit(1)
 		}
 
-		depl, err := client.GetResource("", "Deployment", getKyvernoNameSpace(), config.KyvernoDeploymentName)
+		depl, err := client.GetResource("", "Deployment", config.KyvernoNamespace, config.KyvernoDeploymentName)
 		deplHash := ""
 		if err != nil {
 			log.Log.Info("failed to fetch deployment '%v': %v", config.KyvernoDeploymentName, err.Error())
@@ -136,7 +136,7 @@ func main() {
 		deplHash = fmt.Sprintf("%v", depl.GetUID())
 
 		name := tls.GenerateRootCASecretName(certProps)
-		secretUnstr, err := client.GetResource("", "Secret", getKyvernoNameSpace(), name)
+		secretUnstr, err := client.GetResource("", "Secret", config.KyvernoNamespace, name)
 		if err != nil {
 			log.Log.Info("failed to fetch secret '%v': %v", name, err.Error())
 
@@ -153,7 +153,7 @@ func main() {
 		}
 
 		name = tls.GenerateTLSPairSecretName(certProps)
-		secretUnstr, err = client.GetResource("", "Secret", getKyvernoNameSpace(), name)
+		secretUnstr, err = client.GetResource("", "Secret", config.KyvernoNamespace, name)
 		if err != nil {
 			log.Log.Info("failed to fetch secret '%v': %v", name, err.Error())
 
@@ -169,7 +169,7 @@ func main() {
 			}
 		}
 
-		_, err = kubeClientLeaderElection.CoordinationV1().Leases(getKyvernoNameSpace()).Get(ctx, "kyvernopre-lock", v1.GetOptions{})
+		_, err = kubeClientLeaderElection.CoordinationV1().Leases(config.KyvernoNamespace).Get(ctx, "kyvernopre-lock", v1.GetOptions{})
 		if err != nil {
 			log.Log.Info("Lease 'kyvernopre-lock' not found. Starting clean-up...")
 		} else {
@@ -202,7 +202,7 @@ func main() {
 				Name: "kyvernopre-lock",
 			},
 		}
-		_, err = kubeClientLeaderElection.CoordinationV1().Leases(getKyvernoNameSpace()).Create(ctx, &lease, v1.CreateOptions{})
+		_, err = kubeClientLeaderElection.CoordinationV1().Leases(config.KyvernoNamespace).Create(ctx, &lease, v1.CreateOptions{})
 		if err != nil {
 			log.Log.Info("Failed to create lease 'kyvernopre-lock'")
 		}
@@ -212,7 +212,7 @@ func main() {
 		os.Exit(0)
 	}
 
-	le, err := leaderelection.New("kyvernopre", getKyvernoNameSpace(), kubeClientLeaderElection, run, nil, log.Log.WithName("kyvernopre/LeaderElection"))
+	le, err := leaderelection.New("kyvernopre", config.KyvernoNamespace, kubeClientLeaderElection, run, nil, log.Log.WithName("kyvernopre/LeaderElection"))
 	if err != nil {
 		setupLog.Error(err, "failed to elect a leader")
 		os.Exit(1)
@@ -392,7 +392,7 @@ func addPolicyReportSelectorLabel(client *client.Client) {
 func removeReportChangeRequest(client *client.Client, kind string) error {
 	logger := log.Log.WithName("removeReportChangeRequest")
 
-	ns := getKyvernoNameSpace()
+	ns := config.KyvernoNamespace
 	rcrList, err := client.ListResource("", kind, ns, nil)
 	if err != nil {
 		logger.Error(err, "failed to list reportChangeRequest")
@@ -434,15 +434,6 @@ func removeViolationCRD(client *client.Client) error {
 	return nil
 }
 
-// getKubePolicyNameSpace - setting default KubePolicyNameSpace
-func getKyvernoNameSpace() string {
-	kyvernoNamespace := os.Getenv("KYVERNO_NAMESPACE")
-	if kyvernoNamespace == "" {
-		kyvernoNamespace = "kyverno"
-	}
-	return kyvernoNamespace
-}
-
 func deleteResource(client *client.Client, apiversion, kind, ns, name string) {
 	err := client.DeleteResource(apiversion, kind, ns, name, false)
 	if err != nil && !errors.IsNotFound(err) {

pkg/config/config.go

@@ -3,9 +3,9 @@ package config
 import (
 	"fmt"
 	"math"
-	"os"
 
 	"github.com/go-logr/logr"
+	osutils "github.com/kyverno/kyverno/pkg/utils/os"
 	rest "k8s.io/client-go/rest"
 	clientcmd "k8s.io/client-go/tools/clientcmd"
 )
@@ -65,18 +65,6 @@ const (
 
 	// ClusterRoleKind define the default clusterrole resource kind
 	ClusterRoleKind = "ClusterRole"
-)
-
-var (
-	//KyvernoNamespace is the Kyverno namespace
-	KyvernoNamespace = getKyvernoNameSpace()
-
-	// KyvernoDeploymentName is the Kyverno deployment name
-	KyvernoDeploymentName = getKyvernoDeploymentName()
-
-	//KyvernoServiceName is the Kyverno service name
-	KyvernoServiceName = getKyvernoServiceName()
-
 	//MutatingWebhookServicePath is the path for mutation webhook
 	MutatingWebhookServicePath = "/mutate"
 
@@ -99,6 +87,15 @@ var (
 	ReadinessServicePath = "/health/readiness"
 )
 
+var (
+	//KyvernoNamespace is the Kyverno namespace
+	KyvernoNamespace = osutils.GetEnvWithFallback("KYVERNO_NAMESPACE", "kyverno")
+	// KyvernoDeploymentName is the Kyverno deployment name
+	KyvernoDeploymentName = osutils.GetEnvWithFallback("KYVERNO_DEPLOYMENT", "kyverno")
+	//KyvernoServiceName is the Kyverno service name
+	KyvernoServiceName = osutils.GetEnvWithFallback("KYVERNO_SVC", "kyverno-svc")
+)
+
 //CreateClientConfig creates client config and applies rate limit QPS and burst
 func CreateClientConfig(kubeconfig string, qps float64, burst int, log logr.Logger) (*rest.Config, error) {
 	logger := log.WithName("CreateClientConfig")
@@ -126,30 +123,3 @@ func createClientConfig(kubeconfig string, log logr.Logger) (*rest.Config, error
 	log.V(4).Info("Using specified kubeconfig", "kubeconfig", kubeconfig)
 	return clientcmd.BuildConfigFromFlags("", kubeconfig)
 }
-
-// getKubePolicyNameSpace - setting default KubePolicyNameSpace
-func getKyvernoNameSpace() string {
-	kyvernoNamespace := os.Getenv("KYVERNO_NAMESPACE")
-	if kyvernoNamespace == "" {
-		kyvernoNamespace = "kyverno"
-	}
-	return kyvernoNamespace
-}
-
-// getKyvernoServiceName - setting default KyvernoServiceName
-func getKyvernoServiceName() string {
-	webhookServiceName := os.Getenv("KYVERNO_SVC")
-	if webhookServiceName == "" {
-		webhookServiceName = "kyverno-svc"
-	}
-	return webhookServiceName
-}
-
-// getKyvernoDeploymentName - setting default KyvernoServiceName
-func getKyvernoDeploymentName() string {
-	name := os.Getenv("KYVERNO_DEPLOYMENT")
-	if name == "" {
-		name = "kyverno"
-	}
-	return name
-}

pkg/config/metricsconfig.go

@@ -73,7 +73,7 @@ func NewMetricsConfigData(rclient kubernetes.Interface, log logr.Logger) (*Metri
 	}
 
 	if cmName != "" {
-		kyvernoNamespace := getKyvernoNameSpace()
+		kyvernoNamespace := KyvernoNamespace
 		configMap, err := rclient.CoreV1().ConfigMaps(kyvernoNamespace).Get(context.TODO(), mcd.cmName, metav1.GetOptions{})
 		if err != nil {
 			return nil, fmt.Errorf("error occurred while fetching the metrics configmap at %s/%s: %w", kyvernoNamespace, mcd.cmName, err)

pkg/utils/os/env.go

@@ -0,0 +1,10 @@
+package os
+
+import "os"
+
+func GetEnvWithFallback(name, fallback string) string {
+	if value := os.Getenv(name); value != "" {
+		return value
+	}
+	return fallback
+}