inventory.py 文件源码

def runs_on(target):
    """
    A decorator that picks the correct target server from the inventory
    file.
    Can be called with either target = 'hadoop_master' or 'spark_master'
    (which can be different machines)
    """
    def decorator(func):
        @wraps(func)
        def wrapper(*args, **kwargs):
            if target == 'hadoop_master':
                env.host_string = hadoop_master
            elif target == 'spark_master':
                env.host_string = spark_master
            else:
                raise ValueError('Unhandled target %d' % target)
            func(*args, **kwargs)
        return wrapper
    return decorator