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{-| Implementation of the Ganeti Query2 cluster queries.

 -}

{-

Copyright (C) 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.Query.Cluster

  ( clusterMasterNodeName

  , isWatcherPaused

  ) where

import Control.Exception (try)

import Control.Monad (liftM)

import Data.Char (isSpace)

import Numeric (readDec)

import Ganeti.Config

import Ganeti.Errors

import Ganeti.Logging

import Ganeti.Objects

import Ganeti.Path

import Ganeti.Utils (getCurrentTime)

-- | Get master node name.

clusterMasterNodeName :: ConfigData -> ErrorResult String

clusterMasterNodeName cfg =

  let cluster = configCluster cfg

      masterNodeUuid = clusterMasterNode cluster

  in liftM nodeName $ getNode cfg masterNodeUuid

isWatcherPaused :: IO (Maybe Integer)

isWatcherPaused = do

  logDebug "Checking if the watcher is paused"

  wfile <- watcherPauseFile

  contents <- try $ readFile wfile :: IO (Either IOError String)

  case contents of

    Left _ -> return Nothing

    Right s -> case readDec (dropWhile isSpace s) of

                 [(n, rest)] | all isSpace rest -> do

                   now <- getCurrentTime

                   return $ if n > now then Just n else Nothing

                 _ -> do

                   logWarning $ "Watcher pause file contents '" ++ s

                                 ++ "' not parsable as int"

                   return Nothing