Allow displaying the instance map in hbal

This is similar to --print-nodes, but with much fewer fields.

Ganeti/HTools/CLI.hs

@@ -34,6 +34,7 @@ module Ganeti.HTools.CLI
     , shTemplate
     -- * The options
     , oPrintNodes
+    , oPrintInsts
     , oPrintCommands
     , oOneline
     , oNoHeaders
@@ -79,6 +80,7 @@ defaultLuxiSocket = "/var/run/ganeti/socket/ganeti-master"
 -- | Command line options structure.
 data Options = Options
     { optShowNodes :: Bool           -- ^ Whether to show node status
+    , optShowInsts :: Bool           -- ^ Whether to show the instance map
     , optShowCmds  :: Maybe FilePath -- ^ Whether to show the command list
     , optOneline   :: Bool           -- ^ Switch output to a single line
     , optOutPath   :: FilePath       -- ^ Path to the output directory
@@ -110,6 +112,7 @@ data Options = Options
 defaultOptions :: Options
 defaultOptions  = Options
  { optShowNodes = False
+ , optShowInsts = False
  , optShowCmds  = Nothing
  , optOneline   = False
  , optNoHeaders = False
@@ -145,6 +148,11 @@ oPrintNodes = Option "p" ["print-nodes"]
               (NoArg (\ opts -> opts { optShowNodes = True }))
               "print the final node list"
 
+oPrintInsts :: OptType
+oPrintInsts = Option "" ["print-instances"]
+              (NoArg (\ opts -> opts { optShowInsts = True }))
+              "print the final instance map"
+
 oPrintCommands :: OptType
 oPrintCommands = Option "C" ["print-commands"]
                  (OptArg ((\ f opts -> opts { optShowCmds = Just f }) .

Ganeti/HTools/Cluster.hs

@@ -41,9 +41,11 @@ module Ganeti.HTools.Cluster
     , printSolution
     , printSolutionLine
     , formatCmds
-    , printNodes
     , involvedNodes
     , splitJobs
+    -- * Display functions
+    , printNodes
+    , printInsts
     -- * Balacing functions
     , checkMove
     , tryBalance
@@ -684,6 +686,20 @@ printNodes nl =
                  "pri" "sec" "p_fmem" "p_fdsk" "r_cpu"::String
     in unlines (header:map helper snl)
 
+-- | Print the instance list.
+printInsts :: Node.List -> Instance.List -> String
+printInsts nl il =
+    let sil = sortBy (compare `on` Instance.idx) (Container.elems il)
+        m_name = maximum . map (length . Instance.name) $ sil
+        m_nnm  = maximum . map (length . Node.name) $ Container.elems nl
+        helper inst = printf "%2s %-*s %-*s %-*s"
+                      "  " m_name (Instance.name inst)
+                      m_nnm (Container.nameOf nl (Instance.pNode inst))
+                      m_nnm (Container.nameOf nl (Instance.sNode inst))
+        header = printf "%2s %-*s %-*s %-*s"
+                 "  " m_name "Name" m_nnm "Pri_node" m_nnm "Sec_node"::String
+    in unlines (header:map helper sil)
+
 -- | Shows statistics for a given node list.
 printStats :: Node.List -> String
 printStats nl =

hbal.1

@@ -33,6 +33,7 @@ Algorithm options:
 Reporting options:
 .BI "[ -C[" file "] ]"
 .B "[ -p ]"
+.B "[ --print-instances ]"
 .B "[ -o ]"
 .B "[ -v... | -q ]"
 
@@ -194,6 +195,11 @@ resource allocation in Ganeti) and thus we start a new jobset.
 Prints the before and after node status, in a format designed to allow
 the user to understand the node's most important parameters.
 
+.TP
+.B --print-instances
+Prints the before and after instance map. This is less useful as the
+node status, but it can help in understanding instance moves.
+
 The node list will contain these informations:
 .RS
 .TP

hbal.hs

@@ -56,6 +56,7 @@ import Ganeti.Jobs
 options :: [OptType]
 options =
     [ oPrintNodes
+    , oPrintInsts
     , oPrintCommands
     , oOneline
     , oNodeFile
@@ -227,6 +228,11 @@ main = do
          putStrLn "Cluster is not N+1 happy, continuing but no guarantee \
                   \that the cluster will end N+1 happy."
 
+  when (optShowInsts opts) $ do
+         putStrLn ""
+         putStrLn "Initial instance map:"
+         putStrLn $ Cluster.printInsts nl il
+
   when (optShowNodes opts) $
        do
          putStrLn "Initial cluster status:"
@@ -257,7 +263,7 @@ main = do
   (fin_tbl, cmd_strs) <- iterateDepth ini_tbl (optMaxLength opts)
                          (optDiskMoves opts)
                          nmlen imlen [] oneline min_cv
-  let (Cluster.Table fin_nl _ fin_cv fin_plc) = fin_tbl
+  let (Cluster.Table fin_nl fin_il fin_cv fin_plc) = fin_tbl
       ord_plc = reverse fin_plc
       sol_msg = if null fin_plc
                 then printf "No solution found\n"
@@ -296,6 +302,11 @@ main = do
                 exitWith $ ExitFailure 1
               Just master -> execJobSet master csf fin_nl il cmd_jobs)
 
+  when (optShowInsts opts) $ do
+         putStrLn ""
+         putStrLn "Final instance map:"
+         putStr $ Cluster.printInsts fin_nl fin_il
+
   when (optShowNodes opts) $
        do
          let ini_cs = Cluster.totalResources nl