set nniManagerIp

def setNNIManagerIp(experiment_config, port, config_file_name):
    '''set nniManagerIp'''
    if experiment_config.get('nniManagerIp') is None:
        return True, None
    ip_config_dict = dict()
    ip_config_dict['nni_manager_ip'] = { 'nniManagerIp' : experiment_config['nniManagerIp'] }
    response = rest_put(cluster_metadata_url(port), json.dumps(ip_config_dict), REST_TIME_OUT)
    err_message = None
    if not response or not response.status_code == 200:
        if response is not None:
            err_message = response.text
            _, stderr_full_path = get_log_path(config_file_name)
            with open(stderr_full_path, 'a+') as fout:
                fout.write(json.dumps(json.loads(err_message), indent=4, sort_keys=True, separators=(',', ':')))
        return False, err_message
    return True, None