Move saving of a command list to CLI

Move the function that saves a list of a command in a file
to CLI.hs. In this way, it is reusable by other htools.
Signed-off-by: Klaus Aehlig <aehlig@google.com>
Reviewed-by: Hrvoje Ribicic <riba@google.com>

src/Ganeti/HTools/CLI.hs

@@ -36,6 +36,7 @@ module Ganeti.HTools.CLI
   , parseYesNo
   , parseISpecString
   , shTemplate
+  , maybeSaveCommands
   , maybePrintNodes
   , maybePrintInsts
   , maybeShowWarnings
@@ -720,6 +721,22 @@ shTemplate =
          \  fi\n\
          \}\n\n"
 
+-- | Optionally show or save a list of commands
+maybeSaveCommands :: String -- ^ Informal description
+                  -> Options
+                  -> String -- ^ commands
+                  -> IO ()
+maybeSaveCommands msg opts cmds =
+  case optShowCmds opts of
+    Nothing -> return ()
+    Just "-" -> do
+      putStrLn ""
+      putStrLn msg
+      putStr . unlines .  map ("  " ++) . filter (/= "  check") . lines $ cmds
+    Just out_path -> do
+      writeFile out_path (shTemplate ++ cmds)
+      printf "The commands have been written to file '%s'\n" out_path
+
 -- | Optionally print the node list.
 maybePrintNodes :: Maybe [String]       -- ^ The field list
                 -> String               -- ^ Informational message

src/Ganeti/HTools/Program/Hbal.hs

@@ -33,7 +33,7 @@ module Ganeti.HTools.Program.Hbal
 import Control.Exception (bracket)
 import Control.Monad
 import Data.List
-import Data.Maybe (isJust, isNothing, fromJust)
+import Data.Maybe (isNothing)
 import Data.IORef
 import System.Exit
 import System.IO
@@ -168,20 +168,6 @@ printStats ini_nl fin_nl = do
   printf "Final:    mem=%d disk=%d\n"
              (Cluster.csFmem fin_cs) (Cluster.csFdsk fin_cs)
 
--- | Saves the rebalance commands to a text file.
-saveBalanceCommands :: Options -> String -> IO ()
-saveBalanceCommands opts cmd_data = do
-  let out_path = fromJust $ optShowCmds opts
-  putStrLn ""
-  if out_path == "-"
-    then printf "Commands to run to reach the above solution:\n%s"
-           (unlines . map ("  " ++) .
-            filter (/= "  check") .
-            lines $ cmd_data)
-    else do
-      writeFile out_path (shTemplate ++ cmd_data)
-      printf "The commands have been written to file '%s'\n" out_path
-
 -- | Wrapper over execJobSet checking for early termination via an IORef.
 execCancelWrapper :: Annotator -> String -> Node.List
                   -> Instance.List -> IORef Int -> [JobSet] -> IO (Result ())
@@ -409,8 +395,8 @@ main opts args = do
 
   let cmd_jobs = Cluster.splitJobs cmd_strs
 
-  when (isJust $ optShowCmds opts) .
-       saveBalanceCommands opts $ Cluster.formatCmds cmd_jobs
+  maybeSaveCommands "Commands to run to reach the above solution:" opts
+    $ Cluster.formatCmds cmd_jobs
 
   maybeSaveData (optSaveCluster opts) "balanced" "after balancing"
                 ini_cdata { cdNodes = fin_nl, cdInstances = fin_il }