code: def _run_tf(self, cmd, cmd_args=[], stream=False):
          
          args = [self.tf_path, cmd] + cmd_args
          arg_str = ' '.join(args)
          logger.info('Running terraform command: %s', arg_str)
          out, retcode = run_cmd(arg_str, stream=stream)
          if retcode != 0:
              logger.critical('Terraform command (%s) failed with exit code '
                              '%d:\n%s', arg_str, retcode, out)
              raise Exception('terraform %s failed' % cmd)
          return out
docs: Run a single terraform command via :py:func:`~.utils.run_cmd`;
          raise exception on non-zero exit status.
  
          :param cmd: terraform command to run
          :type cmd: str
          :param cmd_args: arguments to command
          :type cmd_args: :std:term:`list`
          :return: command output
          :rtype: str
          :raises: Exception on non-zero exit