mycookbooks.py 文件源码

def parse_config(filename):
    """ parses the YAML config file and expands any environment variables """

    pattern = re.compile(r'^\<%= ENV\[\'(.*)\'\] %\>(.*)$')
    yaml.add_implicit_resolver("!pathex", pattern)

    def pathex_constructor(loader, node):
        value = loader.construct_scalar(node)
        envVar, remainingPath = pattern.match(value).groups()
        return os.environ[envVar] + remainingPath

    yaml.add_constructor('!pathex', pathex_constructor)

    with open(filename) as f:
        return(
            yaml.load(f)
        )