// assume your k8s manifests in another repo, mine is same repo, just in order to show git clone step
    stage('Checkout K8S manifests') {
      steps {
        script {
          dir(dir_path) {
            container('git') {
              if (! fileExists('learning_by_doing/README.md')) {
                sh """
                git clone //github.com/wadexu007/learning_by_doing.git
                ls -lhrt
                """
              } else {
                  sh 'echo manifes repo already exist.'
              }
            }
          }
        }
      }
    }

    stage('Build manifests with Kustomize') {
      steps {
        script {
          dir(dir_path) {
            container('kubectl-kustomize') {
                sh """
                cd learning_by_doing/Kustomize/demo-manifests/services/demo-app/dev/
                kustomize edit set image $DOCKER_HUB_CREDS_USR/$PROJECT_IMAGE_WITH_TAG
                kustomize build > $WORKSPACE/$dir_path/deployment.yaml
                """
            }
          }
        }
      }
    }

    stage('Deploy to GKE test cluster') {
			environment{
				PROJECT_ID = 'xperiences-eng-cn-dev'
        CLUSTER_NAME = 'xpe-spark-test-gke'
        REGION = 'asia-east2'
        CREDENTIALS_ID = 'gcp_sa_json_key'
      }
      steps {
        script {
          dir(dir_path) {
            container('kubectl-kustomize') {
                sh """
                chown 1000:1000 deployment.yaml
                echo start to deploy to cluster $CLUSTER_NAME
                """
                step([
                  $class: 'KubernetesEngineBuilder',
                  projectId: env.PROJECT_ID,
                  clusterName: env.CLUSTER_NAME,
                  location: env.REGION,
                  manifestPattern: 'deployment.yaml',
                  credentialsId: env.CREDENTIALS_ID,
                  verifyDeployments: false])
                  // verifyDeployments does not work for non-default namespace
            }
          }
        }
      }
    }