Synnefo » snf-ganeti

{-| Implementation of command-line functions.

This module holds the common command-line related functions for the

binaries, separated into this module since "Ganeti.Utils" is

used in many other places and this is more IO oriented.

-}

{-

Copyright (C) 2009, 2010, 2011, 2012, 2013 Google Inc.

This program is free software; you can redistribute it and/or modify

it under the terms of the GNU General Public License as published by

the Free Software Foundation; either version 2 of the License, or

(at your option) any later version.

This program is distributed in the hope that it will be useful, but

WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

General Public License for more details.

You should have received a copy of the GNU General Public License

along with this program; if not, write to the Free Software

Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA

02110-1301, USA.

-}

module Ganeti.HTools.CLI

  ( Options(..)

  , OptType

  , defaultOptions

  , Ganeti.HTools.CLI.parseOpts

  , parseOptsInner

  , parseYesNo

  , parseISpecString

  , shTemplate

  , maybePrintNodes

  , maybePrintInsts

  , maybeShowWarnings

  , printKeys

  , printFinal

  , setNodeStatus

  -- * The options

  , oDataFile

  , oDiskMoves

  , oDiskTemplate

  , oSpindleUse

  , oDynuFile

  , oEvacMode

  , oExInst

  , oExTags

  , oExecJobs

  , oForce

  , oGroup

  , oIAllocSrc

  , oIgnoreNonRedundant

  , oInstMoves

  , oJobDelay

  , genOLuxiSocket

  , oLuxiSocket

  , oMachineReadable

  , oMaxCpu

  , oMaxSolLength

  , oMinDisk

  , oMinGain

  , oMinGainLim

  , oMinScore

  , oNoHeaders

  , oNoSimulation

  , oNodeSim

  , oNodeTags

  , oOfflineMaintenance

  , oOfflineNode

  , oOneStepOnly

  , oOutputDir

  , oPrintCommands

  , oPrintInsts

  , oPrintMoves

  , oPrintNodes

  , oQuiet

  , oRapiMaster

  , oSaveCluster

  , oSelInst

  , oShowHelp

  , oShowVer

  , oShowComp

  , oSkipNonRedundant

  , oStdSpec

  , oTieredSpec

  , oVerbose

  , oPriority

  , genericOpts

  ) where

import Control.Monad

import Data.Char (toUpper)

import Data.Maybe (fromMaybe)

import System.Console.GetOpt

import System.IO

import Text.Printf (printf)

import qualified Ganeti.HTools.Container as Container

import qualified Ganeti.HTools.Node as Node

import qualified Ganeti.Path as Path

import Ganeti.HTools.Types

import Ganeti.BasicTypes

import Ganeti.Common as Common

import Ganeti.Types

import Ganeti.Utils

-- * Data types

-- | Command line options structure.

data Options = Options

  { optDataFile    :: Maybe FilePath -- ^ Path to the cluster data file

  , optDiskMoves   :: Bool           -- ^ Allow disk moves

  , optInstMoves   :: Bool           -- ^ Allow instance moves

  , optDiskTemplate :: Maybe DiskTemplate  -- ^ Override for the disk template

  , optSpindleUse  :: Maybe Int      -- ^ Override for the spindle usage

  , optDynuFile    :: Maybe FilePath -- ^ Optional file with dynamic use data

  , optEvacMode    :: Bool           -- ^ Enable evacuation mode

  , optExInst      :: [String]       -- ^ Instances to be excluded

  , optExTags      :: Maybe [String] -- ^ Tags to use for exclusion

  , optExecJobs    :: Bool           -- ^ Execute the commands via Luxi

  , optForce       :: Bool           -- ^ Force the execution

  , optGroup       :: Maybe GroupID  -- ^ The UUID of the group to process

  , optIAllocSrc   :: Maybe FilePath -- ^ The iallocation spec

  , optIgnoreNonRedundant :: Bool    -- ^ Ignore non-redundant instances

  , optSelInst     :: [String]       -- ^ Instances to be excluded

  , optLuxi        :: Maybe FilePath -- ^ Collect data from Luxi

  , optJobDelay    :: Double         -- ^ Delay before executing first job

  , optMachineReadable :: Bool       -- ^ Output machine-readable format

  , optMaster      :: String         -- ^ Collect data from RAPI

  , optMaxLength   :: Int            -- ^ Stop after this many steps

  , optMcpu        :: Maybe Double   -- ^ Override max cpu ratio for nodes

  , optMdsk        :: Double         -- ^ Max disk usage ratio for nodes

  , optMinGain     :: Score          -- ^ Min gain we aim for in a step

  , optMinGainLim  :: Score          -- ^ Limit below which we apply mingain

  , optMinScore    :: Score          -- ^ The minimum score we aim for

  , optNoHeaders   :: Bool           -- ^ Do not show a header line

  , optNoSimulation :: Bool          -- ^ Skip the rebalancing dry-run

  , optNodeSim     :: [String]       -- ^ Cluster simulation mode

  , optNodeTags    :: Maybe [String] -- ^ List of node tags to restrict to 

  , optOffline     :: [String]       -- ^ Names of offline nodes

  , optOfflineMaintenance :: Bool    -- ^ Pretend all instances are offline

  , optOneStepOnly :: Bool           -- ^ Only do the first step

  , optOutPath     :: FilePath       -- ^ Path to the output directory

  , optPrintMoves  :: Bool           -- ^ Whether to show the instance moves

  , optSaveCluster :: Maybe FilePath -- ^ Save cluster state to this file

  , optShowCmds    :: Maybe FilePath -- ^ Whether to show the command list

  , optShowHelp    :: Bool           -- ^ Just show the help

  , optShowComp    :: Bool           -- ^ Just show the completion info

  , optShowInsts   :: Bool           -- ^ Whether to show the instance map

  , optShowNodes   :: Maybe [String] -- ^ Whether to show node status

  , optShowVer     :: Bool           -- ^ Just show the program version

  , optSkipNonRedundant :: Bool      -- ^ Skip nodes with non-redundant instance

  , optStdSpec     :: Maybe RSpec    -- ^ Requested standard specs

  , optTestCount   :: Maybe Int      -- ^ Optional test count override

  , optTieredSpec  :: Maybe RSpec    -- ^ Requested specs for tiered mode

  , optReplay      :: Maybe String   -- ^ Unittests: RNG state

  , optVerbose     :: Int            -- ^ Verbosity level

  , optPriority    :: Maybe OpSubmitPriority -- ^ OpCode submit priority

  } deriving Show

-- | Default values for the command line options.

defaultOptions :: Options

defaultOptions  = Options

  { optDataFile    = Nothing

  , optDiskMoves   = True

  , optInstMoves   = True

  , optDiskTemplate = Nothing

  , optSpindleUse  = Nothing

  , optDynuFile    = Nothing

  , optEvacMode    = False

  , optExInst      = []

  , optExTags      = Nothing

  , optExecJobs    = False

  , optForce       = False

  , optGroup       = Nothing

  , optIAllocSrc   = Nothing

  , optIgnoreNonRedundant = False

  , optSelInst     = []

  , optLuxi        = Nothing

  , optJobDelay    = 10

  , optMachineReadable = False

  , optMaster      = ""

  , optMaxLength   = -1

  , optMcpu        = Nothing

  , optMdsk        = defReservedDiskRatio

  , optMinGain     = 1e-2

  , optMinGainLim  = 1e-1

  , optMinScore    = 1e-9

  , optNoHeaders   = False

  , optNoSimulation = False

  , optNodeSim     = []

  , optNodeTags    = Nothing

  , optSkipNonRedundant = False

  , optOffline     = []

  , optOfflineMaintenance = False

  , optOneStepOnly = False

  , optOutPath     = "."

  , optPrintMoves  = False

  , optSaveCluster = Nothing

  , optShowCmds    = Nothing

  , optShowHelp    = False

  , optShowComp    = False

  , optShowInsts   = False

  , optShowNodes   = Nothing

  , optShowVer     = False

  , optStdSpec     = Nothing

  , optTestCount   = Nothing

  , optTieredSpec  = Nothing

  , optReplay      = Nothing

  , optVerbose     = 1

  , optPriority    = Nothing

  }

-- | Abbreviation for the option type.

type OptType = GenericOptType Options

instance StandardOptions Options where

  helpRequested = optShowHelp

  verRequested  = optShowVer

  compRequested = optShowComp

  requestHelp o = o { optShowHelp = True }

  requestVer  o = o { optShowVer  = True }

  requestComp o = o { optShowComp = True }

-- * Helper functions

parseISpecString :: String -> String -> Result RSpec

parseISpecString descr inp = do

  let sp = sepSplit ',' inp

      err = Bad ("Invalid " ++ descr ++ " specification: '" ++ inp ++

                 "', expected disk,ram,cpu")

  when (length sp < 3 || length sp > 4) err

  prs <- mapM (\(fn, val) -> fn val) $

         zip [ annotateResult (descr ++ " specs disk") . parseUnit

             , annotateResult (descr ++ " specs memory") . parseUnit

             , tryRead (descr ++ " specs cpus")

             , tryRead (descr ++ " specs spindles")

             ] sp

  case prs of

    {- Spindles are optional, so that they are not needed when exclusive storage

       is disabled. When exclusive storage is disabled, spindles are ignored,

       so the actual value doesn't matter. We use 1 as a default so that in

       case someone forgets and exclusive storage is enabled, we don't run into

       weird situations. -}

    [dsk, ram, cpu] -> return $ RSpec cpu ram dsk 1

    [dsk, ram, cpu, spn] -> return $ RSpec cpu ram dsk spn

    _ -> err

-- | Disk template choices.

optComplDiskTemplate :: OptCompletion

optComplDiskTemplate = OptComplChoices $

                       map diskTemplateToRaw [minBound..maxBound]

-- * Command line options

oDataFile :: OptType

oDataFile =

  (Option "t" ["text-data"]

   (ReqArg (\ f o -> Ok o { optDataFile = Just f }) "FILE")

   "the cluster data FILE",

   OptComplFile)

oDiskMoves :: OptType

oDiskMoves =

  (Option "" ["no-disk-moves"]

   (NoArg (\ opts -> Ok opts { optDiskMoves = False}))

   "disallow disk moves from the list of allowed instance changes,\

   \ thus allowing only the 'cheap' failover/migrate operations",

   OptComplNone)

oDiskTemplate :: OptType

oDiskTemplate =

  (Option "" ["disk-template"]

   (reqWithConversion diskTemplateFromRaw

    (\dt opts -> Ok opts { optDiskTemplate = Just dt })

    "TEMPLATE") "select the desired disk template",

   optComplDiskTemplate)

oSpindleUse :: OptType

oSpindleUse =

  (Option "" ["spindle-use"]

   (reqWithConversion (tryRead "parsing spindle-use")

    (\su opts -> do

       when (su < 0) $

            fail "Invalid value of the spindle-use (expected >= 0)"

       return $ opts { optSpindleUse = Just su })

    "SPINDLES") "select how many virtual spindle instances use\

                \ [default read from cluster]",

   OptComplFloat)

oSelInst :: OptType

oSelInst =

  (Option "" ["select-instances"]

   (ReqArg (\ f opts -> Ok opts { optSelInst = sepSplit ',' f }) "INSTS")

   "only select given instances for any moves",

   OptComplManyInstances)

oInstMoves :: OptType

oInstMoves =

  (Option "" ["no-instance-moves"]

   (NoArg (\ opts -> Ok opts { optInstMoves = False}))

   "disallow instance (primary node) moves from the list of allowed,\

   \ instance changes, thus allowing only slower, but sometimes\

   \ safer, drbd secondary changes",

   OptComplNone)

oDynuFile :: OptType

oDynuFile =

  (Option "U" ["dynu-file"]

   (ReqArg (\ f opts -> Ok opts { optDynuFile = Just f }) "FILE")

   "Import dynamic utilisation data from the given FILE",

   OptComplFile)

oEvacMode :: OptType

oEvacMode =

  (Option "E" ["evac-mode"]

   (NoArg (\opts -> Ok opts { optEvacMode = True }))

   "enable evacuation mode, where the algorithm only moves\

   \ instances away from offline and drained nodes",

   OptComplNone)

oExInst :: OptType

oExInst =

  (Option "" ["exclude-instances"]

   (ReqArg (\ f opts -> Ok opts { optExInst = sepSplit ',' f }) "INSTS")

   "exclude given instances from any moves",

   OptComplManyInstances)

oExTags :: OptType

oExTags =

  (Option "" ["exclusion-tags"]

   (ReqArg (\ f opts -> Ok opts { optExTags = Just $ sepSplit ',' f })

    "TAG,...") "Enable instance exclusion based on given tag prefix",

   OptComplString)

oExecJobs :: OptType

oExecJobs =

  (Option "X" ["exec"]

   (NoArg (\ opts -> Ok opts { optExecJobs = True}))

   "execute the suggested moves via Luxi (only available when using\

   \ it for data gathering)",

   OptComplNone)

oForce :: OptType

oForce =

  (Option "f" ["force"]

   (NoArg (\ opts -> Ok opts {optForce = True}))

   "force the execution of this program, even if warnings would\

   \ otherwise prevent it",

   OptComplNone)

oGroup :: OptType

oGroup =

  (Option "G" ["group"]

   (ReqArg (\ f o -> Ok o { optGroup = Just f }) "ID")

   "the target node group (name or UUID)",

   OptComplOneGroup)

oIAllocSrc :: OptType

oIAllocSrc =

  (Option "I" ["ialloc-src"]

   (ReqArg (\ f opts -> Ok opts { optIAllocSrc = Just f }) "FILE")

   "Specify an iallocator spec as the cluster data source",

   OptComplFile)

oIgnoreNonRedundant :: OptType

oIgnoreNonRedundant =

  (Option "" ["ignore-non-redundant"]

   (NoArg (\ opts -> Ok opts { optIgnoreNonRedundant = True }))

    "Pretend that there are no non-redundant instances in the cluster",

    OptComplNone)

oJobDelay :: OptType

oJobDelay =

  (Option "" ["job-delay"]

   (reqWithConversion (tryRead "job delay")

    (\d opts -> Ok opts { optJobDelay = d }) "SECONDS")

   "insert this much delay before the execution of repair jobs\

   \ to allow the tool to continue processing instances",

   OptComplFloat)

genOLuxiSocket :: String -> OptType

genOLuxiSocket defSocket =

  (Option "L" ["luxi"]

   (OptArg ((\ f opts -> Ok opts { optLuxi = Just f }) .

            fromMaybe defSocket) "SOCKET")

   ("collect data via Luxi, optionally using the given SOCKET path [" ++

    defSocket ++ "]"),

   OptComplFile)

oLuxiSocket :: IO OptType

oLuxiSocket = liftM genOLuxiSocket Path.defaultLuxiSocket

oMachineReadable :: OptType

oMachineReadable =

  (Option "" ["machine-readable"]

   (OptArg (\ f opts -> do

              flag <- parseYesNo True f

              return $ opts { optMachineReadable = flag }) "CHOICE")

   "enable machine readable output (pass either 'yes' or 'no' to\

   \ explicitly control the flag, or without an argument defaults to\

   \ yes",

   optComplYesNo)

oMaxCpu :: OptType

oMaxCpu =

  (Option "" ["max-cpu"]

   (reqWithConversion (tryRead "parsing max-cpu")

    (\mcpu opts -> do

       when (mcpu <= 0) $

            fail "Invalid value of the max-cpu ratio, expected >0"

       return $ opts { optMcpu = Just mcpu }) "RATIO")

   "maximum virtual-to-physical cpu ratio for nodes (from 0\

   \ upwards) [default read from cluster]",

   OptComplFloat)

oMaxSolLength :: OptType

oMaxSolLength =

  (Option "l" ["max-length"]

   (reqWithConversion (tryRead "max solution length")

    (\i opts -> Ok opts { optMaxLength = i }) "N")

   "cap the solution at this many balancing or allocation\

   \ rounds (useful for very unbalanced clusters or empty\

   \ clusters)",

   OptComplInteger)

oMinDisk :: OptType

oMinDisk =

  (Option "" ["min-disk"]

   (reqWithConversion (tryRead "min free disk space")

    (\n opts -> Ok opts { optMdsk = n }) "RATIO")

   "minimum free disk space for nodes (between 0 and 1) [0]",

   OptComplFloat)

oMinGain :: OptType

oMinGain =

  (Option "g" ["min-gain"]

   (reqWithConversion (tryRead "min gain")

    (\g opts -> Ok opts { optMinGain = g }) "DELTA")

   "minimum gain to aim for in a balancing step before giving up",

   OptComplFloat)

oMinGainLim :: OptType

oMinGainLim =

  (Option "" ["min-gain-limit"]

   (reqWithConversion (tryRead "min gain limit")

    (\g opts -> Ok opts { optMinGainLim = g }) "SCORE")

   "minimum cluster score for which we start checking the min-gain",

   OptComplFloat)

oMinScore :: OptType

oMinScore =

  (Option "e" ["min-score"]

   (reqWithConversion (tryRead "min score")

    (\e opts -> Ok opts { optMinScore = e }) "EPSILON")

   "mininum score to aim for",

   OptComplFloat)

oNoHeaders :: OptType

oNoHeaders =

  (Option "" ["no-headers"]

   (NoArg (\ opts -> Ok opts { optNoHeaders = True }))

   "do not show a header line",

   OptComplNone)

oNoSimulation :: OptType

oNoSimulation =

  (Option "" ["no-simulation"]

   (NoArg (\opts -> Ok opts {optNoSimulation = True}))

   "do not perform rebalancing simulation",

   OptComplNone)

oNodeSim :: OptType

oNodeSim =

  (Option "" ["simulate"]

   (ReqArg (\ f o -> Ok o { optNodeSim = f:optNodeSim o }) "SPEC")

   "simulate an empty cluster, given as\

   \ 'alloc_policy,num_nodes,disk,ram,cpu'",

   OptComplString)

oNodeTags :: OptType

oNodeTags =

  (Option "" ["node-tags"]

   (ReqArg (\ f opts -> Ok opts { optNodeTags = Just $ sepSplit ',' f })

    "TAG,...") "Restrict to nodes with the given tags",

   OptComplString)

oOfflineMaintenance :: OptType

oOfflineMaintenance =

  (Option "" ["offline-maintenance"]

   (NoArg (\ opts -> Ok opts {optOfflineMaintenance = True}))

   "Schedule offline maintenance, i.e., pretend that all instance are\

   \ offline.",

   OptComplNone)

oOfflineNode :: OptType

oOfflineNode =

  (Option "O" ["offline"]

   (ReqArg (\ n o -> Ok o { optOffline = n:optOffline o }) "NODE")

   "set node as offline",

   OptComplOneNode)

oOneStepOnly :: OptType

oOneStepOnly =

  (Option "" ["one-step-only"]

   (NoArg (\ opts -> Ok opts {optOneStepOnly = True}))

   "Only do the first step",

   OptComplNone)

oOutputDir :: OptType

oOutputDir =

  (Option "d" ["output-dir"]

   (ReqArg (\ d opts -> Ok opts { optOutPath = d }) "PATH")

   "directory in which to write output files",

   OptComplDir)

oPrintCommands :: OptType

oPrintCommands =

  (Option "C" ["print-commands"]

   (OptArg ((\ f opts -> Ok opts { optShowCmds = Just f }) .

            fromMaybe "-")

    "FILE")

   "print the ganeti command list for reaching the solution,\

   \ if an argument is passed then write the commands to a\

   \ file named as such",

   OptComplNone)

oPrintInsts :: OptType

oPrintInsts =

  (Option "" ["print-instances"]

   (NoArg (\ opts -> Ok opts { optShowInsts = True }))

   "print the final instance map",

   OptComplNone)

oPrintMoves :: OptType

oPrintMoves =

  (Option "" ["print-moves"]

   (NoArg (\ opts -> Ok opts { optPrintMoves = True }))

   "print the moves of the instances",

   OptComplNone)

oPrintNodes :: OptType

oPrintNodes =

  (Option "p" ["print-nodes"]

   (OptArg ((\ f opts ->

               let (prefix, realf) = case f of

                                       '+':rest -> (["+"], rest)

                                       _ -> ([], f)

                   splitted = prefix ++ sepSplit ',' realf

               in Ok opts { optShowNodes = Just splitted }) .

            fromMaybe []) "FIELDS")

   "print the final node list",

   OptComplNone)

oQuiet :: OptType

oQuiet =

  (Option "q" ["quiet"]

   (NoArg (\ opts -> Ok opts { optVerbose = optVerbose opts - 1 }))

   "decrease the verbosity level",

   OptComplNone)

oRapiMaster :: OptType

oRapiMaster =

  (Option "m" ["master"]

   (ReqArg (\ m opts -> Ok opts { optMaster = m }) "ADDRESS")

   "collect data via RAPI at the given ADDRESS",

   OptComplHost)

oSaveCluster :: OptType

oSaveCluster =

  (Option "S" ["save"]

   (ReqArg (\ f opts -> Ok opts { optSaveCluster = Just f }) "FILE")

   "Save cluster state at the end of the processing to FILE",

   OptComplNone)

oSkipNonRedundant :: OptType

oSkipNonRedundant =

  (Option "" ["skip-non-redundant"]

   (NoArg (\ opts -> Ok opts { optSkipNonRedundant = True }))

    "Skip nodes that host a non-redundant instance",

    OptComplNone)

oStdSpec :: OptType

oStdSpec =

  (Option "" ["standard-alloc"]

   (ReqArg (\ inp opts -> do

              tspec <- parseISpecString "standard" inp

              return $ opts { optStdSpec = Just tspec } )

    "STDSPEC")

   "enable standard specs allocation, given as 'disk,ram,cpu'",

   OptComplString)

oTieredSpec :: OptType

oTieredSpec =

  (Option "" ["tiered-alloc"]

   (ReqArg (\ inp opts -> do

              tspec <- parseISpecString "tiered" inp

              return $ opts { optTieredSpec = Just tspec } )

    "TSPEC")

   "enable tiered specs allocation, given as 'disk,ram,cpu'",

   OptComplString)

oVerbose :: OptType

oVerbose =

  (Option "v" ["verbose"]

   (NoArg (\ opts -> Ok opts { optVerbose = optVerbose opts + 1 }))

   "increase the verbosity level",

   OptComplNone)

oPriority :: OptType

oPriority =

  (Option "" ["priority"]

   (ReqArg (\ inp opts -> do

              prio <- parseSubmitPriority inp

              Ok opts { optPriority = Just prio }) "PRIO")

   "set the priority of submitted jobs",

    OptComplChoices (map fmtSubmitPriority [minBound..maxBound]))

-- | Generic options.

genericOpts :: [GenericOptType Options]

genericOpts =  [ oShowVer

               , oShowHelp

               , oShowComp

               ]

-- * Functions

-- | Wrapper over 'Common.parseOpts' with our custom options.

parseOpts :: [String]               -- ^ The command line arguments

          -> String                 -- ^ The program name

          -> [OptType]              -- ^ The supported command line options

          -> [ArgCompletion]        -- ^ The supported command line arguments

          -> IO (Options, [String]) -- ^ The resulting options and leftover

                                    -- arguments

parseOpts = Common.parseOpts defaultOptions

-- | A shell script template for autogenerated scripts.

shTemplate :: String

shTemplate =

  printf "#!/bin/sh\n\n\

         \# Auto-generated script for executing cluster rebalancing\n\n\

         \# To stop, touch the file /tmp/stop-htools\n\n\

         \set -e\n\n\

         \check() {\n\

         \  if [ -f /tmp/stop-htools ]; then\n\

         \    echo 'Stop requested, exiting'\n\

         \    exit 0\n\

         \  fi\n\

         \}\n\n"

-- | Optionally print the node list.

maybePrintNodes :: Maybe [String]       -- ^ The field list

                -> String               -- ^ Informational message

                -> ([String] -> String) -- ^ Function to generate the listing

                -> IO ()

maybePrintNodes Nothing _ _ = return ()

maybePrintNodes (Just fields) msg fn = do

  hPutStrLn stderr ""

  hPutStrLn stderr (msg ++ " status:")

  hPutStrLn stderr $ fn fields

-- | Optionally print the instance list.

maybePrintInsts :: Bool   -- ^ Whether to print the instance list

                -> String -- ^ Type of the instance map (e.g. initial)

                -> String -- ^ The instance data

                -> IO ()

maybePrintInsts do_print msg instdata =

  when do_print $ do

    hPutStrLn stderr ""

    hPutStrLn stderr $ msg ++ " instance map:"

    hPutStr stderr instdata

-- | Function to display warning messages from parsing the cluster

-- state.

maybeShowWarnings :: [String] -- ^ The warning messages

                  -> IO ()

maybeShowWarnings fix_msgs =

  unless (null fix_msgs) $ do

    hPutStrLn stderr "Warning: cluster has inconsistent data:"

    hPutStrLn stderr . unlines . map (printf "  - %s") $ fix_msgs

-- | Format a list of key, value as a shell fragment.

printKeys :: String              -- ^ Prefix to printed variables

          -> [(String, String)]  -- ^ List of (key, value) pairs to be printed

          -> IO ()

printKeys prefix =

  mapM_ (\(k, v) ->

           printf "%s_%s=%s\n" prefix (map toUpper k) (ensureQuoted v))

-- | Prints the final @OK@ marker in machine readable output.

printFinal :: String    -- ^ Prefix to printed variable

           -> Bool      -- ^ Whether output should be machine readable;

                        -- note: if not, there is nothing to print

           -> IO ()

printFinal prefix True =

  -- this should be the final entry

  printKeys prefix [("OK", "1")]

printFinal _ False = return ()

-- | Potentially set the node as offline based on passed offline list.

setNodeOffline :: [Ndx] -> Node.Node -> Node.Node

setNodeOffline offline_indices n =

  if Node.idx n `elem` offline_indices

    then Node.setOffline n True

    else n

-- | Set node properties based on command line options.

setNodeStatus :: Options -> Node.List -> IO Node.List

setNodeStatus opts fixed_nl = do

  let offline_passed = optOffline opts

      all_nodes = Container.elems fixed_nl

      offline_lkp = map (lookupName (map Node.name all_nodes)) offline_passed

      offline_wrong = filter (not . goodLookupResult) offline_lkp

      offline_names = map lrContent offline_lkp

      offline_indices = map Node.idx $

                        filter (\n -> Node.name n `elem` offline_names)

                               all_nodes

      m_cpu = optMcpu opts

      m_dsk = optMdsk opts

  unless (null offline_wrong) .

         exitErr $ printf "wrong node name(s) set as offline: %s\n"

                   (commaJoin (map lrContent offline_wrong))

  let setMCpuFn = case m_cpu of

                    Nothing -> id

                    Just new_mcpu -> flip Node.setMcpu new_mcpu

  let nm = Container.map (setNodeOffline offline_indices .

                          flip Node.setMdsk m_dsk .

                          setMCpuFn) fixed_nl

  return nm