fix steps

Jenkinsfile

@@ -83,8 +83,15 @@ spec:
         }
 
         stage('Deploy to Kubernetes') {
-            withKubeConfig([credentialsId: "${KUBE_CONFIG_ID}"]) {
-                sh 'kubectl apply -f deploy/kubernetes/'
+            steps {
+                withKubeConfig([credentialsId: env.KUBE_CONFIG_ID]) {
+                    script {
+                        sh '''
+                        set -e
+                        kubectl apply -f deploy/kubernetes/ --validate=true
+                        '''
+                    }
+                }
             }
         }
     }