Print key from a running instance's metadata

def awsReadInstanceTag():
  """Print key from a running instance's metadata"""
  parser = argparse.ArgumentParser()

  parser.add_argument("--tag",
                      dest="tag",
                      required=True,
                      help="Which instance tag to read")

  cli = parser.parse_args()
  print haze.ec2.readMyEC2Tag(tagName=cli.tag)