hookenv.py 文件源码

def _metadata_unit(unit):
    """Given the name of a unit (e.g. apache2/0), get the unit charm's
    metadata.yaml. Very similar to metadata() but allows us to inspect
    other units. Unit needs to be co-located, such as a subordinate or
    principal/primary.

    :returns: metadata.yaml as a python object.

    """
    basedir = os.sep.join(charm_dir().split(os.sep)[:-2])
    unitdir = 'unit-{}'.format(unit.replace(os.sep, '-'))
    joineddir = os.path.join(basedir, unitdir, 'charm', 'metadata.yaml')
    if not os.path.exists(joineddir):
        return None
    with open(joineddir) as md:
        return yaml.safe_load(md)