def create_osd_keyring(conn, cluster, key):
    """
    Run on osd node, writes the bootstrap key if not there yet.
    """
    logger = conn.logger
    path = '/var/lib/ceph/bootstrap-osd/{cluster}.keyring'.format(
        cluster=cluster,
    )
    if not conn.remote_module.path_exists(path):
        logger.warning('osd keyring does not exist yet, creating one')
        conn.remote_module.write_keyring(path, key)
Run on osd node, writes the bootstrap key if not there yet.