Jenkins+Kubernetesで動的に並列ジョブを定義したい場合

jenkinspipeline.yaml

def labelname = "sample"

pipeline {
  agent {
    kubernetes {
      label labelname
      yaml '''
apiVersion: v1
kind: Pod
metadata:
  labels:
    sample: sample
spec:
  containers:
  - name: sample
    image: sample
    command:
    - cat
    tty: true
    resources:
      limits:
        memory: "768Mi"
        cpu: "1000m"
      requests:
        memory: "512Mi"
        cpu: "500m"
'''
    }
  }
  stages {
    stage('sample-stage') {
      steps {
        container('sample'){ 
          script {
            def sitelist = [1,2,3]

            tasks = [:]
            for (name in sitelist) {
                def siteName = name

                tasks[siteName] = {
                    container('sample'){ 
                        sh """
                            echo Hello
                        """
                    }
                }
            }
            parallel tasks
          }        
        }
      }
    }
  }
  post {
    always {
      cleanWs()
    }
  }   
}