A way to set unique name of pod(process).

[gongweibao]

Trainingjob is a stateful application: each parameter server and worker needs to be uniquely addressable to support all the different patterns of distributed training

Tensorflow/k8s create many Kubernetes Jobs with unique stateful name, so they avoid to use etcd to get the unique-persist name: https://github.com/tensorflow/k8s/blob/master/tf_job_design_doc.md#controller