Cities and towns may, except as otherwise provided by law, by ordinance provide for the election at any regular municipal election or for the appointment of such officers as are deemed needful or proper for the good government of the city or town and the due exercise of its corporate powers, fix their terms of office, fix their compensation and prescribe the duties of such officers, their liabilities and powers and require them to give bond in such sum and to be conditioned and approved as the council may prescribe.