provider.py 文件源码

def _populate_keys_from_metadata_server(self):
        # get_instance_metadata is imported here because of a circular
        # dependency.
        boto.log.debug("Retrieving credentials from metadata server.")
        from boto.utils import get_instance_metadata
        timeout = config.getfloat('Boto', 'metadata_service_timeout', 1.0)
        attempts = config.getint('Boto', 'metadata_service_num_attempts', 1)
        # The num_retries arg is actually the total number of attempts made,
        # so the config options is named *_num_attempts to make this more
        # clear to users.
        metadata = get_instance_metadata(
            timeout=timeout, num_retries=attempts,
            data='meta-data/iam/security-credentials/')
        if metadata:
            # I'm assuming there's only one role on the instance profile.
            security = list(metadata.values())[0]
            self._access_key = security['AccessKeyId']
            self._secret_key = self._convert_key_to_str(security['SecretAccessKey'])
            self._security_token = security['Token']
            expires_at = security['Expiration']
            self._credential_expiry_time = datetime.strptime(
                expires_at, "%Y-%m-%dT%H:%M:%SZ")
            boto.log.debug("Retrieved credentials will expire in %s at: %s",
                           self._credential_expiry_time - datetime.now(), expires_at)