docker_session_.py 文件源码

def _blob_exists(self, digest):
    """Check the remote for the given layer."""
    # HEAD the blob, and check for a 200
    resp, unused_content = self._transport.Request(
        '{base_url}/blobs/{digest}'.format(
            base_url=self._base_url(),
            digest=digest),
        method='HEAD', accepted_codes=[httplib.OK, httplib.NOT_FOUND])

    return resp.status == httplib.OK  # pytype: disable=attribute-error