Synnefo » snf-ganeti

{-| Solver for N+1 cluster errors

-}

{-

Copyright (C) 2009, 2010, 2011 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 Main (main) where

import Data.List

import Data.Maybe (isJust, fromJust)

import Monad

import System (exitWith, ExitCode(..))

import System.IO

import qualified System

import qualified Ganeti.HTools.Cluster as Cluster

import Ganeti.HTools.CLI

import Ganeti.HTools.IAlloc

import Ganeti.HTools.Types

import Ganeti.HTools.Loader (RqType(..), Request(..), ClusterData(..))

import Ganeti.HTools.ExtLoader (loadExternalData)

-- | Options list and functions

options :: [OptType]

options =

    [ oPrintNodes

    , oDataFile

    , oNodeSim

    , oShowVer

    , oShowHelp

    ]

processResults :: (Monad m) =>

                  RqType -> Cluster.AllocSolution

               -> m Cluster.AllocSolution

processResults _ (Cluster.AllocSolution { Cluster.asSolutions = [],

                                          Cluster.asLog = msgs }) =

  fail $ intercalate ", " msgs

processResults (Evacuate _) as = return as

processResults _ as =

    case Cluster.asSolutions as of

      _:[] -> return as

      _ -> fail "Internal error: multiple allocation solutions"

-- | Process a request and return new node lists

processRequest :: Request

               -> Result Cluster.AllocSolution

processRequest request =

  let Request rqtype (ClusterData gl nl il _) = request

  in case rqtype of

       Allocate xi reqn -> Cluster.tryMGAlloc gl nl il xi reqn

       Relocate idx reqn exnodes -> Cluster.tryMGReloc gl nl il

                                    idx reqn exnodes

       Evacuate exnodes -> Cluster.tryMGEvac gl nl il exnodes

-- | Reads the request from the data file(s)

readRequest :: Options -> [String] -> IO Request

readRequest opts args = do

  when (null args) $ do

         hPutStrLn stderr "Error: this program needs an input file."

         exitWith $ ExitFailure 1

  input_data <- readFile (head args)

  r1 <- case (parseData input_data) of

          Bad err -> do

            hPutStrLn stderr $ "Error: " ++ err

            exitWith $ ExitFailure 1

          Ok rq -> return rq

  (if isJust (optDataFile opts) ||  (not . null . optNodeSim) opts

   then do

     cdata <- loadExternalData opts

     let Request rqt _ = r1

     return $ Request rqt cdata

   else return r1)

-- | Main function.

main :: IO ()

main = do

  cmd_args <- System.getArgs

  (opts, args) <- parseOpts cmd_args "hail" options

  let shownodes = optShowNodes opts

  request <- readRequest opts args

  let Request rq cdata = request

  when (isJust shownodes) $ do

         hPutStrLn stderr "Initial cluster status:"

         hPutStrLn stderr $ Cluster.printNodes (cdNodes cdata)

                       (fromJust shownodes)

  let sols = processRequest request >>= processResults rq

  let (ok, info, rn) =

          case sols of

            Ok as -> (True, "Request successful: " ++

                            intercalate ", " (Cluster.asLog as),

                      Cluster.asSolutions as)

            Bad s -> (False, "Request failed: " ++ s, [])

      resp = formatResponse ok info rq rn

  putStrLn resp