573.17  Parties.
  The official board or officer letting the contract, the principal contractor, all claimants for labor and material who have filed their claim, and the surety on any bond given for the performance of the contract shall be joined as plaintiffs or defendants.
[C24, 27, 31, 35, 39, §10314; C46, 50, 54, 58, 62, 66, 71, 73, 75, 77, 79, 81, §573.17]