Select a peer from the db at random
    Return None if the table is empty

def atlasdb_get_random_peer( con=None, path=None ):
    """
    Select a peer from the db at random
    Return None if the table is empty
    """
    ret = {}

    with AtlasDBOpen(con=con, path=path) as dbcon:

        num_peers = atlasdb_num_peers( con=con, path=path )
        if num_peers is None or num_peers == 0:
            # no peers
            ret['peer_hostport'] = None

        else:
            r = random.randint(1, num_peers)

            sql = "SELECT * FROM peers WHERE peer_index = ?;"
            args = (r,)

            cur = dbcon.cursor()
            res = atlasdb_query_execute( cur, sql, args )

            ret = {'peer_hostport': None}
            for row in res:
                ret.update( row )
                break


    return ret['peer_hostport']