It will be better to avoid deleting unexisting worker services.

[leileiwan]

hi， In the function “ deletePodsAndServices”，we clean the services by delete all the services of pod including the worker pod. it will be better to avoid deleting unexisting worker services.

reference:

• https://github.com/kubeflow/pytorch-operator/pull/231

• https://github.com/kubeflow/pytorch-operator/issues/228

  func (pc *PyTorchController) deletePodsAndServices(job *pyv1.PyTorchJob, pods []*v1.Pod) error {
  if len(pods) == 0 {
      return nil
  }
  
  // Delete nothing when the cleanPodPolicy is None or Running.
  if *job.Spec.CleanPodPolicy == common.CleanPodPolicyNone ||
      *job.Spec.CleanPodPolicy == common.CleanPodPolicyRunning {
      return nil
  }
  
  for _, pod := range pods {
      if err := pc.PodControl.DeletePod(pod.Namespace, pod.Name, job); err != nil {
          return err
      }
      // Pod and service have the same name, thus the service could be deleted using pod's name.
      if err := pc.ServiceControl.DeleteService(pod.Namespace, pod.Name, job); err != nil {
          return err
      }
  }
  return nil
  }

[gaocegege]

/kind feature