[CI|K8s] Fix k8s tests on Jenkins

Jenkinsfile

@@ -990,8 +990,8 @@ def k8sTest(versions){
           withBeatsEnv(false) {
             sh(label: "Install kind", script: ".ci/scripts/install-kind.sh")
             sh(label: "Install kubectl", script: ".ci/scripts/install-kubectl.sh")
-            sh(label: "Integration tests", script: "MODULE=kubernetes make -C metricbeat integration-tests")
             sh(label: "Setup kind", script: ".ci/scripts/kind-setup.sh")
+            sh(label: "Integration tests", script: "MODULE=kubernetes make -C metricbeat integration-tests")
             sh(label: "Deploy to kubernetes",script: "make -C deploy/kubernetes test")
             sh(label: 'Delete cluster', script: 'kind delete cluster')
           }

dev-tools/mage/kubernetes/kind.go

@@ -51,12 +51,30 @@ func (m *KindIntegrationTestStep) Setup(env map[string]string) error {
 	_, exists := env["KUBECONFIG"]
 	if exists {
 		// do nothing
-		return nil
+		if mg.Verbose() {
+			fmt.Println("KUBECONFIG: ", env["KUBECONFIG"])
+		}
+		if _, err := os.Stat(env["KUBECONFIG"]); err == nil {
+			return nil
+		} else if os.IsNotExist(err) {
+			if mg.Verbose() {
+				fmt.Println("KUBECONFIG file not found: ", env["KUBECONFIG"], err)
+			}
+		}
 	}
 	_, exists = env["KUBE_CONFIG"]
 	if exists {
 		// do nothing
-		return nil
+		if mg.Verbose() {
+			fmt.Println("KUBE_CONFIG: ", env["KUBE_CONFIG"])
+		}
+		if _, err := os.Stat(env["KUBE_CONFIG"]); err == nil {
+			return nil
+		} else if os.IsNotExist(err) {
+			if mg.Verbose() {
+				fmt.Println("KUBE_CONFIG file not found: ", env["KUBE_CONFIG"], err)
+			}
+		}
 	}
 	_, err := exec.LookPath("kind")
 	if err != nil {
@@ -80,6 +98,9 @@ func (m *KindIntegrationTestStep) Setup(env map[string]string) error {
 		return err
 	}
 	kubeConfig := filepath.Join(kubeCfgDir, "kubecfg")
+	if mg.Verbose() {
+		fmt.Println("Kubeconfig: ", kubeConfig)
+	}
 	if err := os.MkdirAll(kubeCfgDir, os.ModePerm); err != nil {
 		return err
 	}