Always print all variables in machine readable version

As discussed in cover letter of patch series introducing hcheck, in
machine readable version we should always print values of all variables.
When hbal simulation was not run, FINAL values are equal to INIT values.

Signed-off-by: Agata Murawska <agatamurawska@google.com>
Reviewed-by: René Nussbaumer <rn@google.com>

htools/Ganeti/HTools/Program/Hcheck.hs

@@ -233,6 +233,15 @@ simulateRebalance opts (gidx, (nl, il)) = do
       let (Cluster.Table fin_nl fin_il _ _) = fin_tbl
       return (gidx, (fin_nl, fin_il))
 
+-- | Decide whether to simulate rebalance.
+maybeSimulateRebalance :: Bool             -- ^ Whether to simulate rebalance
+                       -> Options          -- ^ Command line options
+                       -> [(Gdx, (Node.List, Instance.List))] -- ^ Group data
+                       -> IO([(Gdx, (Node.List, Instance.List))])
+maybeSimulateRebalance True opts cluster =
+    mapM (simulateRebalance opts) cluster
+maybeSimulateRebalance False _ cluster = return cluster
+
 -- | Prints the final @OK@ marker in machine readable output.
 printFinalHTC :: Bool -> IO ()
 printFinalHTC = printFinal htcPrefix
@@ -264,24 +273,32 @@ main opts args = do
   when nosimulation $ do
     unless (verbose == 0 || machineread) $
       printf "Running in no-simulation mode. Exiting.\n"
-    printFinalHTC machineread
-    exitWith ExitSuccess
 
   when (length splitinstances > 0) $ do
     unless (verbose == 0 || machineread) $
        printf "Split instances found, simulation of re-balancing not possible\n"
-    exitWith $ ExitFailure 1
 
   unless needrebalance $ do
     unless (verbose == 0 || machineread) $
       printf "No need to rebalance cluster, no problems found. Exiting.\n"
-    printFinalHTC machineread
-    exitWith ExitSuccess
 
-  rebalancedcluster <- mapM (simulateRebalance opts) splitcluster
-  newgroupstats <- mapM (perGroupChecks verbose machineread Rebalanced gl)
+  let exitOK = nosimulation || not needrebalance
+      simulate = not nosimulation && length splitinstances == 0 && needrebalance
+
+  rebalancedcluster <- maybeSimulateRebalance simulate opts splitcluster
+
+  when (simulate || machineread) $ do
+    newgroupstats <- mapM (perGroupChecks verbose machineread Rebalanced gl)
                      rebalancedcluster
-  let newclusterstats = map sum (transpose newgroupstats) :: [Int]
-  _ <- printClusterStats verbose machineread Rebalanced newclusterstats canrebalance
+    -- We do not introduce new split instances during rebalance
+    let newsplitinstances = splitinstances
+        newclusterstats = map sum (transpose newgroupstats) :: [Int]
+        newcanrebalance = length newsplitinstances == 0
+
+    _ <- printClusterStats verbose machineread Rebalanced newclusterstats
+                           newcanrebalance
+    return ()
 
   printFinalHTC machineread
+
+  unless exitOK $ exitWith $ ExitFailure 1