Return a list of databases of a MySQL server using the output
    from the ``SHOW DATABASES`` query.

    CLI Example:

    .. code-block:: bash

        salt '*' mysql.db_list

def db_list(**connection_args):
    '''
    Return a list of databases of a MySQL server using the output
    from the ``SHOW DATABASES`` query.

    CLI Example:

    .. code-block:: bash

        salt '*' mysql.db_list
    '''
    dbc = _connect(**connection_args)
    if dbc is None:
        return []
    cur = dbc.cursor()
    qry = 'SHOW DATABASES'
    try:
        _execute(cur, qry)
    except MySQLdb.OperationalError as exc:
        err = 'MySQL Error {0}: {1}'.format(*exc.args)
        __context__['mysql.error'] = err
        log.error(err)
        return []

    ret = []
    results = cur.fetchall()
    for dbs in results:
        ret.append(dbs[0])

    log.debug(ret)
    return ret