Synnefo » snf-ganeti

    , DiskTemplate(..)

    , dtToString

    , dtFromString

-- | Instance disk template type

data DiskTemplate = DTDiskless

                  | DTFile

                  | DTSharedFile

                  | DTPlain

                  | DTBlock

                  | DTDrbd8

                    deriving (Show, Read, Eq)

-- | Converts a DiskTemplate to String

dtToString :: DiskTemplate -> String

dtToString DTDiskless   = C.dtDiskless

dtToString DTFile       = C.dtFile

dtToString DTSharedFile = C.dtSharedFile

dtToString DTPlain      = C.dtPlain

dtToString DTBlock      = C.dtBlock

dtToString DTDrbd8      = C.dtDrbd8

-- | Converts a DiskTemplate from String

dtFromString :: (Monad m) => String -> m DiskTemplate

dtFromString s =

    case () of

      _ | s == C.dtDiskless   -> return DTDiskless

        | s == C.dtFile       -> return DTFile

        | s == C.dtSharedFile -> return DTSharedFile

        | s == C.dtPlain      -> return DTPlain

        | s == C.dtBlock      -> return DTBlock

        | s == C.dtDrbd8      -> return DTDrbd8

        | otherwise           -> fail $ "Invalid disk template: " ++ s

instance JSON.JSON DiskTemplate where

    showJSON = JSON.showJSON . dtToString

    readJSON s = case JSON.readJSON s of

                   JSON.Ok s' -> dtFromString s'

                   JSON.Error e -> JSON.Error $

                                   "Can't parse disk_template as string: " ++ e