Add portList config in PAI trainingService

[SparkSnail]

1. Add portList to PAI mode configurations #1461
2. fix error link in supportTrainingService.md

[ultmaster]

It's working now, but the process is not straightforward (at least to me). Posting an example here:

Let's say you want to launch a tensorboard in the mnist example. So the first step is to write a wrapper script of mnist.py.

pip3 install tensorboard
export TENSORBOARD_PORT=PAI_PORT_LIST_${PAI_CURRENT_TASK_ROLE_NAME}_0_tensorboard
tensorboard --logdir . --port ${!TENSORBOARD_PORT} &
python3 mnist.py

According to this discussion, you need to use indirect expansion ${!XXX} to get the port here, and therefore it's also required to use bash instead of sh in the next step.

Besides, config_pai.yml needs to specify that "it wants a port".

trial:
  command: bash launch_pai.sh
  portList:
    - label: tensorboard
      beginAt: 0
      portNumber: 1

[yds05]

remove extra ','

[SparkSnail]

removed.