Any one or more public agencies may contract with any one or more other public agencies to perform any governmental service, activity, or undertaking which each public agency entering into the contract is authorized by law to perform, including, but not limited to joint contracting for services, supplies and capital equipment, provided that such contract shall be authorized by the governing body of each party to the contract. Such contract shall set forth fully the purposes, powers, rights, objectives and responsibilities of the contracting parties.