Abstract the cluster serialization from hscan.hs

This is currently hardcoded in an internal function in hscan.hs, and we
move it to Text.hs for later use.

Ganeti/HTools/Text.hs

@@ -34,6 +34,7 @@ module Ganeti.HTools.Text
     , serializeInstances
     , serializeNode
     , serializeNodes
+    , serializeCluster
     ) where
 
 import Control.Monad
@@ -81,6 +82,13 @@ serializeInstances :: Node.List -> Instance.List -> String
 serializeInstances nl =
     unlines . map (serializeInstance nl) . Container.elems
 
+-- | Generate complete cluster data from node and instance lists
+serializeCluster :: Node.List -> Instance.List -> String
+serializeCluster nl il =
+  let ndata = serializeNodes nl
+      idata = serializeInstances nl il
+  in ndata ++ ['\n'] ++ idata
+
 -- | Load a node from a field list.
 loadNode :: (Monad m) => [String] -> m (String, Node.Node)
 loadNode [name, tm, nm, fm, td, fd, tc, fo] = do

hscan.hs

@@ -45,7 +45,7 @@ import qualified Ganeti.HTools.Rapi as Rapi
 #endif
 import qualified Ganeti.HTools.Luxi as Luxi
 import qualified Ganeti.HTools.Loader as Loader
-import Ganeti.HTools.Text (serializeNodes, serializeInstances)
+import Ganeti.HTools.Text (serializeCluster)
 
 import Ganeti.HTools.CLI
 import Ganeti.HTools.Types
@@ -94,9 +94,7 @@ processData :: Result (Node.AssocList, Instance.AssocList, [String])
 processData input_data = do
   (nl, il, _) <- input_data >>= Loader.mergeData [] [] []
   let (_, fix_nl) = Loader.checkData nl il
-  let ndata = serializeNodes nl
-      idata = serializeInstances nl il
-      adata = ndata ++ ['\n'] ++ idata
+      adata = serializeCluster nl il
   return (fix_nl, il, adata)
 
 -- | Writes cluster data out