fail to run tensorflow example in https://volcano.sh/en/docs/tf_on_volcano/

[shuaiyy]

What happened:
run the demo in https://volcano.sh/en/docs/tf_on_volcano/

got error

in ps and worker 0

job name = ps
task index = 0
Traceback (most recent call last):
  File "/var/tf_dist_mnist/dist_mnist.py", line 303, in <module>
    tf.app.run()
  File "/opt/conda/lib/python3.5/site-packages/tensorflow/python/platform/app.py", line 126, in run
    _sys.exit(main(argv))
  File "/var/tf_dist_mnist/dist_mnist.py", line 144, in main
    cluster, job_name=FLAGS.job_name, task_index=FLAGS.task_index)
  File "/opt/conda/lib/python3.5/site-packages/tensorflow/python/training/server_lib.py", line 147, in __init__
    self._server_def.SerializeToString(), status)
  File "/opt/conda/lib/python3.5/site-packages/tensorflow/python/framework/errors_impl.py", line 519, in __exit__
    c_api.TF_GetCode(self.status.status))
tensorflow.python.framework.errors_impl.InvalidArgumentError: Could not parse port for local server from ""

in worker 1:

job name = ps
task index = 1
Traceback (most recent call last):
  File "/var/tf_dist_mnist/dist_mnist.py", line 303, in <module>
    tf.app.run()
  File "/opt/conda/lib/python3.5/site-packages/tensorflow/python/platform/app.py", line 126, in run
    _sys.exit(main(argv))
  File "/var/tf_dist_mnist/dist_mnist.py", line 144, in main
    cluster, job_name=FLAGS.job_name, task_index=FLAGS.task_index)
  File "/opt/conda/lib/python3.5/site-packages/tensorflow/python/training/server_lib.py", line 147, in __init__
    self._server_def.SerializeToString(), status)
  File "/opt/conda/lib/python3.5/site-packages/tensorflow/python/framework/errors_impl.py", line 519, in __exit__
    c_api.TF_GetCode(self.status.status))
tensorflow.python.framework.errors_impl.InvalidArgumentError: Task 1 was not defined in job "ps"

What you expected to happen:

the dome in docs can run success

How to reproduce it (as minimally and precisely as possible):

Anything else we need to know?:

Environment:

• Volcano Version: install by master branch，image with latest tag
• Kubernetes version (use kubectl version): 1.18.8
• Cloud provider or hardware configuration:
• OS (e.g. from /etc/os-release): CentOS-7
• Kernel (e.g. uname -a): Linux emr-header-1.cluster-337861 3.10.0-1160.42.2.el7.x86_64 Rename hpw.cloud keyword to volcano.sh #1 SMP Tue Sep 7 14:49:57 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux
• Install tools: kubectl apply -f
• Others:

[hwdef]

This is a documentation error, and the documentation will be updated later