graphql-engine/server/src-lib/Hasura/Backends/MSSQL/Connection.hs
Rakesh Emmadi 1c745959b9 relocate 'ServerReplicas' and 'ResizePoolStrategy' types
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/6448
GitOrigin-RevId: 2d317fd004db63e2830dfb8def92acb51bb576a0
2022-10-20 01:34:17 +00:00

315 lines
10 KiB
Haskell

{-# LANGUAGE TemplateHaskell #-}
{-# OPTIONS_GHC -fno-warn-orphans #-}
-- | MSSQL Connection
--
-- This module handles the connection against an MS SQL Server.
-- It defines the connection string, connection pool, default settings,
-- and conversion functions between MSSQL and graphql-engine.
module Hasura.Backends.MSSQL.Connection
( MSSQLConnConfiguration (MSSQLConnConfiguration),
MSSQLSourceConfig (MSSQLSourceConfig, _mscExecCtx),
MSSQLConnectionInfo (..),
MSSQLPoolSettings (..),
MSSQLExecCtx (..),
MonadMSSQLTx (..),
defaultMSSQLMaxConnections,
createMSSQLPool,
resizeMSSQLPool,
getEnv,
odbcValueToJValue,
mkMSSQLExecCtx,
mkMSSQLAnyQueryTx,
runMSSQLSourceReadTx,
runMSSQLSourceWriteTx,
)
where
import Autodocodec (HasCodec (codec), dimapCodec, disjointEitherCodec, optionalFieldOrNull', optionalFieldWithDefault', requiredField')
import Autodocodec qualified as AC
import Control.Monad.Morph (hoist)
import Control.Monad.Trans.Control
import Data.Aeson
import Data.Aeson qualified as J
import Data.Aeson.TH
import Data.Environment qualified as Env
import Data.Text (pack, unpack)
import Data.Time (localTimeToUTC)
import Database.MSSQL.Pool qualified as MSPool
import Database.MSSQL.Transaction qualified as MSTx
import Database.ODBC.SQLServer qualified as ODBC
import Hasura.Backends.MSSQL.SQL.Error
import Hasura.Base.Error
import Hasura.Incremental (Cacheable (..))
import Hasura.Metadata.DTO.Utils (fromEnvCodec)
import Hasura.Prelude
import Hasura.RQL.Types.ResizePool (ResizePoolStrategy (..), ServerReplicas, getServerReplicasInt)
class MonadError QErr m => MonadMSSQLTx m where
liftMSSQLTx :: MSTx.TxE QErr a -> m a
instance MonadMSSQLTx m => MonadMSSQLTx (ReaderT s m) where
liftMSSQLTx = lift . liftMSSQLTx
instance MonadMSSQLTx m => MonadMSSQLTx (StateT s m) where
liftMSSQLTx = lift . liftMSSQLTx
instance (Monoid w, MonadMSSQLTx m) => MonadMSSQLTx (WriterT w m) where
liftMSSQLTx = lift . liftMSSQLTx
instance MonadIO m => MonadMSSQLTx (MSTx.TxET QErr m) where
liftMSSQLTx = hoist liftIO
-- | ODBC connection string for MSSQL server
newtype MSSQLConnectionString = MSSQLConnectionString {unMSSQLConnectionString :: Text}
deriving (Show, Eq, ToJSON, FromJSON, Cacheable, Hashable, NFData)
-- * Orphan instances
instance Cacheable MSPool.ConnectionString
instance Hashable MSPool.ConnectionString
instance NFData MSPool.ConnectionString
data InputConnectionString
= RawString MSPool.ConnectionString
| FromEnvironment Text
deriving stock (Show, Eq, Generic)
instance Cacheable InputConnectionString
instance Hashable InputConnectionString
instance NFData InputConnectionString
instance HasCodec InputConnectionString where
codec =
dimapCodec
(either RawString FromEnvironment)
(\case RawString m -> Left m; FromEnvironment wEnv -> Right wEnv)
$ disjointEitherCodec codec fromEnvCodec
instance ToJSON InputConnectionString where
toJSON =
\case
(RawString m) -> toJSON m
(FromEnvironment wEnv) -> object ["from_env" .= wEnv]
instance FromJSON InputConnectionString where
parseJSON =
\case
(Object o) -> FromEnvironment <$> o .: "from_env"
s@(String _) -> RawString <$> parseJSON s
_ -> fail "one of string or object must be provided"
data MSSQLPoolSettings = MSSQLPoolSettings
{ _mpsMaxConnections :: Maybe Int,
_mpsTotalMaxConnections :: Maybe Int,
_mpsIdleTimeout :: Int
}
deriving (Show, Eq, Generic)
instance Cacheable MSSQLPoolSettings
instance Hashable MSSQLPoolSettings
instance NFData MSSQLPoolSettings
$(deriveToJSON hasuraJSON ''MSSQLPoolSettings)
instance FromJSON MSSQLPoolSettings where
parseJSON = withObject "MSSQL pool settings" $ \o ->
MSSQLPoolSettings
<$> o .:? "max_connections"
<*> o .:? "total_max_connections"
<*> o .:? "idle_timeout" .!= _mpsIdleTimeout defaultMSSQLPoolSettings
instance HasCodec MSSQLPoolSettings where
codec =
AC.object "MSSQLPoolSettings" $
MSSQLPoolSettings
<$> optionalFieldWithDefault' "max_connections" (Just defaultMSSQLMaxConnections) AC..= _mpsMaxConnections
<*> optionalFieldOrNull' "total_max_connections" AC..= _mpsTotalMaxConnections
<*> optionalFieldWithDefault' "idle_timeout" (_mpsIdleTimeout defaultMSSQLPoolSettings) AC..= _mpsIdleTimeout
defaultMSSQLMaxConnections :: Int
defaultMSSQLMaxConnections = 50
defaultMSSQLPoolSettings :: MSSQLPoolSettings
defaultMSSQLPoolSettings =
MSSQLPoolSettings
{ _mpsMaxConnections = Nothing,
_mpsTotalMaxConnections = Nothing,
_mpsIdleTimeout = 5
}
data MSSQLConnectionInfo = MSSQLConnectionInfo
{ _mciConnectionString :: InputConnectionString,
_mciPoolSettings :: MSSQLPoolSettings
}
deriving (Show, Eq, Generic)
instance Cacheable MSSQLConnectionInfo
instance Hashable MSSQLConnectionInfo
instance NFData MSSQLConnectionInfo
instance HasCodec MSSQLConnectionInfo where
codec =
AC.object "MSSQLConnectionInfo" $
MSSQLConnectionInfo
<$> requiredField' "connection_string" AC..= _mciConnectionString
<*> requiredField' "pool_settings" AC..= _mciPoolSettings
$(deriveToJSON hasuraJSON ''MSSQLConnectionInfo)
instance FromJSON MSSQLConnectionInfo where
parseJSON = withObject "Object" $ \o ->
MSSQLConnectionInfo
<$> ((o .: "database_url") <|> (o .: "connection_string"))
<*> o .:? "pool_settings" .!= defaultMSSQLPoolSettings
data MSSQLConnConfiguration = MSSQLConnConfiguration
{ _mccConnectionInfo :: MSSQLConnectionInfo,
_mccReadReplicas :: Maybe (NonEmpty MSSQLConnectionInfo)
}
deriving (Show, Eq, Generic)
instance Cacheable MSSQLConnConfiguration
instance Hashable MSSQLConnConfiguration
instance NFData MSSQLConnConfiguration
instance HasCodec MSSQLConnConfiguration where
codec =
AC.object "MSSQLConnConfiguration" $
MSSQLConnConfiguration
<$> requiredField' "connection_info" AC..= _mccConnectionInfo
<*> optionalFieldOrNull' "read_replicas" AC..= _mccReadReplicas
$(deriveJSON hasuraJSON {omitNothingFields = True} ''MSSQLConnConfiguration)
createMSSQLPool ::
MonadIO m =>
QErrM m =>
InputConnectionString ->
MSPool.ConnectionOptions ->
Env.Environment ->
m (MSPool.ConnectionString, MSPool.MSSQLPool)
createMSSQLPool iConnString connOptions env = do
connString <- resolveInputConnectionString env iConnString
pool <- liftIO $ MSPool.initMSSQLPool connString connOptions
pure (connString, pool)
resolveInputConnectionString ::
QErrM m =>
Env.Environment ->
InputConnectionString ->
m MSPool.ConnectionString
resolveInputConnectionString env =
\case
(RawString cs) -> pure cs
(FromEnvironment envVar) -> MSPool.ConnectionString <$> getEnv env envVar
getEnv :: QErrM m => Env.Environment -> Text -> m Text
getEnv env k = do
let mEnv = Env.lookupEnv env (unpack k)
case mEnv of
Nothing -> throw400 NotFound $ "environment variable '" <> k <> "' not set"
Just envVal -> return (pack envVal)
type MSSQLRunTx =
forall m a. (MonadIO m, MonadBaseControl IO m) => MSTx.TxET QErr m a -> ExceptT QErr m a
-- | Execution Context required to execute MSSQL transactions
data MSSQLExecCtx = MSSQLExecCtx
{ -- | A function that runs read-only queries
mssqlRunReadOnly :: MSSQLRunTx,
-- | A function that runs read-write queries; run in a transaction
mssqlRunReadWrite :: MSSQLRunTx,
-- | Destroys connection pools
mssqlDestroyConn :: IO (),
-- | Resize pools based on number of server instances,
mssqlResizePools :: ServerReplicas -> IO ()
}
-- | Creates a MSSQL execution context for a single primary pool
mkMSSQLExecCtx :: MSPool.MSSQLPool -> ResizePoolStrategy -> MSSQLExecCtx
mkMSSQLExecCtx pool resizeStrategy =
MSSQLExecCtx
{ mssqlRunReadOnly = \tx -> MSTx.runTxE defaultMSSQLTxErrorHandler tx pool,
mssqlRunReadWrite = \tx -> MSTx.runTxE defaultMSSQLTxErrorHandler tx pool,
mssqlDestroyConn = MSPool.drainMSSQLPool pool,
mssqlResizePools =
case resizeStrategy of
NeverResizePool -> const $ pure ()
ResizePool maxConnections -> resizeMSSQLPool pool maxConnections
}
-- | Resize MSSQL pool by setting the number of connections equal to
-- allowed maximum connections across all server instances divided by
-- number of instances
resizeMSSQLPool :: MSPool.MSSQLPool -> Int -> ServerReplicas -> IO ()
resizeMSSQLPool mssqlPool maxConnections serverReplicas =
MSPool.resizePool mssqlPool (maxConnections `div` getServerReplicasInt serverReplicas)
-- | Run any query discarding its results
mkMSSQLAnyQueryTx :: ODBC.Query -> MSTx.TxET QErr IO ()
mkMSSQLAnyQueryTx q = do
_discard :: [[ODBC.Value]] <- MSTx.multiRowQueryE defaultMSSQLTxErrorHandler q
pure ()
data MSSQLSourceConfig = MSSQLSourceConfig
{ _mscConnectionString :: MSPool.ConnectionString,
_mscExecCtx :: MSSQLExecCtx
}
deriving (Generic)
instance Show MSSQLSourceConfig where
show = show . _mscConnectionString
instance Eq MSSQLSourceConfig where
MSSQLSourceConfig connStr1 _ == MSSQLSourceConfig connStr2 _ =
connStr1 == connStr2
instance Cacheable MSSQLSourceConfig where
unchanged _ = (==)
instance ToJSON MSSQLSourceConfig where
toJSON = toJSON . _mscConnectionString
odbcValueToJValue :: ODBC.Value -> J.Value
odbcValueToJValue = \case
ODBC.TextValue t -> J.String t
ODBC.ByteStringValue b -> J.String $ bsToTxt b
ODBC.BinaryValue b -> J.String $ bsToTxt $ ODBC.unBinary b
ODBC.BoolValue b -> J.Bool b
ODBC.DoubleValue d -> J.toJSON d
ODBC.FloatValue f -> J.toJSON f
ODBC.IntValue i -> J.toJSON i
ODBC.ByteValue b -> J.toJSON b
ODBC.DayValue d -> J.toJSON d
ODBC.TimeOfDayValue td -> J.toJSON td
ODBC.LocalTimeValue l -> J.toJSON l
ODBC.NullValue -> J.Null
ODBC.ZonedTimeValue lt tz -> J.toJSON (localTimeToUTC tz lt)
runMSSQLSourceReadTx ::
(MonadIO m, MonadBaseControl IO m) =>
MSSQLSourceConfig ->
MSTx.TxET QErr m a ->
m (Either QErr a)
runMSSQLSourceReadTx msc =
runExceptT . mssqlRunReadOnly (_mscExecCtx msc)
runMSSQLSourceWriteTx ::
(MonadIO m, MonadBaseControl IO m) =>
MSSQLSourceConfig ->
MSTx.TxET QErr m a ->
m (Either QErr a)
runMSSQLSourceWriteTx msc =
runExceptT . mssqlRunReadWrite (_mscExecCtx msc)