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{-# LANGUAGE CPP #-}

{-| External data loader

This module holds the external data loading, and thus is the only one

depending (via the specialized Text\/Rapi\/Luxi modules) on the actual

libraries implementing the low-level protocols.

-}

{-

Copyright (C) 2009 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.ExtLoader

    ( loadExternalData

    ) where

import Data.Maybe (isJust, fromJust)

import Monad

import System.Posix.Env

import System.IO

import System

import Text.Printf (printf, hPrintf)

import qualified Ganeti.HTools.Luxi as Luxi

#ifndef NO_CURL

import qualified Ganeti.HTools.Rapi as Rapi

#endif

import qualified Ganeti.HTools.Simu as Simu

import qualified Ganeti.HTools.Text as Text

import qualified Ganeti.HTools.Loader as Loader

import qualified Ganeti.HTools.Instance as Instance

import qualified Ganeti.HTools.Node as Node

import Ganeti.HTools.Types

import Ganeti.HTools.CLI

import Ganeti.HTools.Utils (sepSplit, tryRead)

-- | Parse the environment and return the node\/instance names.

--

-- This also hardcodes here the default node\/instance file names.

parseEnv :: () -> IO (String, String)

parseEnv () = do

  a <- getEnvDefault "HTOOLS_NODES" "nodes"

  b <- getEnvDefault "HTOOLS_INSTANCES" "instances"

  return (a, b)

-- | Error beautifier

wrapIO :: IO (Result a) -> IO (Result a)

wrapIO = flip catch (return . Bad . show)

parseUtilisation :: String -> Result (String, DynUtil)

parseUtilisation line =

    let columns = sepSplit ' ' line

    in case columns of

         [name, cpu, mem, dsk, net] -> do

                      rcpu <- tryRead name cpu

                      rmem <- tryRead name mem

                      rdsk <- tryRead name dsk

                      rnet <- tryRead name net

                      let du = DynUtil { cpuWeight = rcpu, memWeight = rmem

                                       , dskWeight = rdsk, netWeight = rnet }

                      return (name, du)

         _ -> Bad $ "Cannot parse line " ++ line

-- | External tool data loader from a variety of sources.

loadExternalData :: Options

                 -> IO (Node.List, Instance.List, [String], String)

loadExternalData opts = do

  (env_node, env_inst) <- parseEnv ()

  let nodef = if optNodeSet opts then optNodeFile opts

              else env_node

      instf = if optInstSet opts then optInstFile opts

              else env_inst

      mhost = optMaster opts

      lsock = optLuxi opts

      simdata = optNodeSim opts

      setRapi = mhost /= ""

      setLuxi = isJust lsock

      setSim = isJust simdata

      setFiles = optNodeSet opts || optInstSet opts

      allSet = filter id [setRapi, setLuxi, setFiles]

      exTags = case optExTags opts of

                 Nothing -> []

                 Just etl -> map (++ ":") etl

  when (length allSet > 1) $

       do

         hPutStrLn stderr ("Error: Only one of the rapi, luxi, and data" ++

                           " files options should be given.")

         exitWith $ ExitFailure 1

  util_contents <- (case optDynuFile opts of

                      Just path -> readFile path

                      Nothing -> return "")

  let util_data = mapM parseUtilisation $ lines util_contents

  util_data' <- (case util_data of

                   Ok x -> return x

                   Bad y -> do

                     hPutStrLn stderr ("Error: can't parse utilisation" ++

                                       " data: " ++ show y)

                     exitWith $ ExitFailure 1)

  input_data <-

      case () of

        _ | setRapi ->

#ifdef NO_CURL

              return $ Bad "RAPI/curl backend disabled at compile time"

#else

              wrapIO $ Rapi.loadData mhost

#endif

          | setLuxi -> wrapIO $ Luxi.loadData $ fromJust lsock

          | setSim -> Simu.loadData $ fromJust simdata

          | otherwise -> wrapIO $ Text.loadData nodef instf

  let ldresult = input_data >>= Loader.mergeData util_data' exTags

  (loaded_nl, il, tags, csf) <-

      (case ldresult of

         Ok x -> return x

         Bad s -> do

           hPrintf stderr "Error: failed to load data. Details:\n%s\n" s

           exitWith $ ExitFailure 1

      )

  let (fix_msgs, fixed_nl) = Loader.checkData loaded_nl il

  unless (null fix_msgs || optVerbose opts == 0) $ do

         hPutStrLn stderr "Warning: cluster has inconsistent data:"

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

  return (fixed_nl, il, tags, csf)