Synnefo » snf-ganeti » ganeti-local

{-| DRBD data collector.

-}

{-

Copyright (C) 2012 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.DataCollectors.Drbd

  ( main

  , options

  , arguments

  ) where

import qualified Control.Exception as E

import Data.Attoparsec.Text.Lazy as A

import Data.Text.Lazy (pack, unpack)

import Text.JSON

import qualified Ganeti.BasicTypes as BT

import qualified Ganeti.Constants as C

import Ganeti.Block.Drbd.Parser(drbdStatusParser)

import Ganeti.Common

import Ganeti.DataCollectors.CLI

import Ganeti.Utils

-- | The default path of the DRBD status file.

-- It is hardcoded because it is not likely to change.

defaultFile :: FilePath

defaultFile = C.drbdStatusFile

-- | The default setting for the maximum amount of not parsed character to

-- print in case of error.

-- It is set to use most of the screen estate on a standard 80x25 terminal.

-- TODO: add the possibility to set this with a command line parameter.

defaultCharNum :: Int

defaultCharNum = 80*20

options :: IO [OptType]

options = return []

-- | The list of arguments supported by the program.

arguments :: [ArgCompletion]

arguments = [ArgCompletion OptComplFile 0 (Just 1)]

-- * Command line options

-- | Main function.

main :: Options -> [String] -> IO ()

main _ args = do

  proc_drbd <- case args of

                 [ ] -> return defaultFile

                 [x] -> return x

                 _   -> exitErr $ "This program takes only one argument," ++

                                  " got '" ++ unwords args ++ "'"

  contents <-

    ((E.try $ readFile proc_drbd) :: IO (Either IOError String)) >>=

      exitIfBad "reading from file" . either (BT.Bad . show) BT.Ok

  output <-

    case A.parse drbdStatusParser $ pack contents of

      A.Fail unparsedText contexts errorMessage -> exitErr $

        show (Prelude.take defaultCharNum $ unpack unparsedText) ++ "\n"

          ++ show contexts ++ "\n" ++ errorMessage

      A.Done _ drbdStatus -> return $ encode drbdStatus

  putStrLn output