-- | Get (primary, secondary) instances of a given node group.
getGroupInstances :: ConfigData -> String -> ([Instance], [Instance])
getGroupInstances cfg gname =
  let gnodes = map uuidOf (getGroupNodes cfg gname)
      ginsts = map (getNodeInstances cfg) gnodes in
  (concatMap fst ginsts, concatMap snd ginsts)
getGroupInstances :: ConfigData -> String -> ([Instance], [Instance])
getGroupInstances cfg gname =
  let gnodes = map uuidOf (getGroupNodes cfg gname)
      ginsts = map (getNodeInstances cfg) gnodes in
  (concatMap fst ginsts, concatMap snd ginsts)
getGroupInstances cfg gname =
  let gnodes = map uuidOf (getGroupNodes cfg gname)
      ginsts = map (getNodeInstances cfg) gnodes in
  (concatMap fst ginsts, concatMap snd ginsts)