src/Graylog/Types.hs

   1 {-# LANGUAGE LambdaCase      #-}
   2 {-# LANGUAGE RecordWildCards #-}
   3
   4 module Graylog.Types
   5    ( Graylog
   6    , _graylogHost
   7    , _graylogPort
   8    , _graylogAddress
   9    , _graylogSocket
  10    , _graylogHostName
  11    , _graylogChunkSize
  12    , ChunkSize
  13
  14    , defaultChunkSize
  15    , openGraylog
  16    , closeGraylog
  17    ) where
  18
  19 import           Data.List
  20 import           Data.Text      (Text)
  21 import qualified Data.Text      as T
  22 import           Network.BSD
  23 import           Network.Socket
  24
  25 -- | The maximum size of each datagram when using UDP transit methods.
  26 type ChunkSize = Word
  27
  28 -- | Handle for a socket connected to Graylog. In some cases this socket
  29 -- is UDP and will not have a maintained session.
  30 data Graylog
  31    = Graylog
  32       { _graylogHost      :: String
  33       , _graylogPort      :: String
  34       , _graylogAddress   :: AddrInfo
  35       , _graylogSocket    :: Socket
  36       , _graylogHostName  :: Text
  37       , _graylogChunkSize :: ChunkSize
  38       }
  39
  40 defaultChunkSize :: ChunkSize
  41 defaultChunkSize = 8192
  42
  43 openGraylog
  44    :: HostName          -- ^ The host on which graylog is running.
  45    -> ServiceName       -- ^ The port on which graylog is running.
  46    -> ChunkSize         -- ^ The maximum size of each UDP datagram.
  47    -> IO (Either String Graylog)
  48 openGraylog h p cksize
  49    | cksize < 1024 = return $ Left "ChunkSize must be at least 1024."
  50    | otherwise     = getAddrInfo Nothing (Just h) (Just p) >>= \case
  51    []     -> return $ Left "No address info found."
  52    infos ->
  53       case find (\i -> addrSocketType i == Datagram) infos of
  54          Nothing -> return $ Left "No datagram info found for address."
  55          Just  i -> do
  56             sock <- socket (addrFamily i) Datagram defaultProtocol
  57             connect sock (addrAddress i)
  58             hostname <- getHostName
  59             return $ Right $ Graylog h p i sock (T.pack hostname) cksize
  60
  61 closeGraylog :: Graylog -> IO ()
  62 closeGraylog Graylog{..} = close _graylogSocket