{-# LANGUAGE TemplateHaskell #-} -- | Migrations for the Hasura catalog. -- -- To add a new migration: -- -- 1. Bump the catalog version number in @src-rsr/catalog_version.txt@. -- 2. Add a migration script in the @src-rsr/migrations/@ directory with the name -- @_to_.sql@. -- 3. Create a downgrade script in the @src-rsr/migrations/@ directory with the name -- @_to_.sql@. -- 4. If making a new release, add the mapping from application version to catalog -- schema version in @src-rsr/catalog_versions.txt@. -- 5. If appropriate, add the change to @server/src-rsr/initialise.sql@ for fresh installations -- of hasura. -- -- The Template Haskell code in this module will automatically compile the new migration script into -- the @graphql-engine@ executable. -- -- NOTE: Please have a look at the `server/documentation/migration-guidelines.md` before adding any new migration -- if you haven't already looked at it module Hasura.Server.Migrate ( MigrationResult (..), migrateCatalog, latestCatalogVersion, downgradeCatalog, ) where import Control.Monad.Trans.Control (MonadBaseControl) import Data.Aeson qualified as A import Data.FileEmbed (makeRelativeToProject) import Data.HashMap.Strict.InsOrd qualified as OMap import Data.Text qualified as T import Data.Text.IO qualified as TIO import Data.Time.Clock (UTCTime) import Database.PG.Query qualified as PG import Hasura.Backends.Postgres.Connection.MonadTx import Hasura.Backends.Postgres.Execute.Types import Hasura.Backends.Postgres.SQL.Types import Hasura.Base.Error import Hasura.Logging (Hasura, LogLevel (..), ToEngineLog (..)) import Hasura.Prelude import Hasura.RQL.DDL.Schema import Hasura.RQL.DDL.Schema.LegacyCatalog import Hasura.RQL.Types.ApiLimit import Hasura.RQL.Types.Backend import Hasura.RQL.Types.Common import Hasura.RQL.Types.CustomTypes import Hasura.RQL.Types.Metadata import Hasura.RQL.Types.Network import Hasura.RQL.Types.SourceCustomization import Hasura.SQL.AnyBackend qualified as AB import Hasura.SQL.Backend import Hasura.Server.Init (DowngradeOptions (..), databaseUrlOption, _envVar) import Hasura.Server.Logging (StartupLog (..)) import Hasura.Server.Migrate.Internal import Hasura.Server.Migrate.LatestVersion import Hasura.Server.Migrate.Version import Hasura.Server.Types (MaintenanceMode (..)) import Language.Haskell.TH.Lib qualified as TH import Language.Haskell.TH.Syntax qualified as TH import System.Directory (doesFileExist) data MigrationResult = MRNothingToDo | MRInitialized | -- | old catalog version MRMigrated Text | MRMaintanenceMode deriving (Show, Eq) instance ToEngineLog MigrationResult Hasura where toEngineLog result = toEngineLog $ StartupLog { slLogLevel = LevelInfo, slKind = "catalog_migrate", slInfo = A.toJSON $ case result of MRNothingToDo -> "Already at the latest catalog version (" <> latestCatalogVersionString <> "); nothing to do." MRInitialized -> "Successfully initialized the catalog (at version " <> latestCatalogVersionString <> ")." MRMigrated oldVersion -> "Successfully migrated from catalog version " <> oldVersion <> " to version " <> latestCatalogVersionString <> "." MRMaintanenceMode -> "Catalog migrations are skipped because the graphql-engine is in maintenance mode" } -- A migration and (hopefully) also its inverse if we have it. -- Polymorphic because `m` can be any `MonadTx`, `MonadIO` when -- used in the `migrations` function below. data MigrationPair m = MigrationPair { mpMigrate :: m (), mpDown :: Maybe (m ()) } migrateCatalog :: forall m. ( MonadTx m, MonadIO m, MonadBaseControl IO m ) => Maybe (SourceConnConfiguration ('Postgres 'Vanilla)) -> ExtensionsSchema -> MaintenanceMode () -> UTCTime -> m (MigrationResult, Metadata) migrateCatalog maybeDefaultSourceConfig extensionsSchema maintenanceMode migrationTime = do catalogSchemaExists <- doesSchemaExist (SchemaName "hdb_catalog") versionTableExists <- doesTableExist (SchemaName "hdb_catalog") (TableName "hdb_version") metadataTableExists <- doesTableExist (SchemaName "hdb_catalog") (TableName "hdb_metadata") migrationResult <- if | maintenanceMode == (MaintenanceModeEnabled ()) -> do if | not catalogSchemaExists -> throw500 "unexpected: hdb_catalog schema not found in maintenance mode" | not versionTableExists -> throw500 "unexpected: hdb_catalog.hdb_version table not found in maintenance mode" | not metadataTableExists -> throw500 $ "the \"hdb_catalog.hdb_metadata\" table is expected to exist and contain" <> " the metadata of the graphql-engine" | otherwise -> pure MRMaintanenceMode | otherwise -> case catalogSchemaExists of False -> initialize True True -> case versionTableExists of False -> initialize False True -> migrateFrom =<< liftTx getCatalogVersion metadata <- liftTx fetchMetadataFromCatalog pure (migrationResult, metadata) where -- initializes the catalog, creating the schema if necessary initialize :: Bool -> m MigrationResult initialize createSchema = do liftTx $ PG.catchE defaultTxErrorHandler $ when createSchema $ PG.unitQ "CREATE SCHEMA hdb_catalog" () False enablePgcryptoExtension extensionsSchema multiQ $(makeRelativeToProject "src-rsr/initialise.sql" >>= PG.sqlFromFile) updateCatalogVersion let emptyMetadata' = case maybeDefaultSourceConfig of Nothing -> emptyMetadata Just defaultSourceConfig -> -- insert metadata with default source let defaultSourceMetadata = AB.mkAnyBackend $ SourceMetadata @('Postgres 'Vanilla) defaultSource PostgresVanillaKind mempty mempty defaultSourceConfig Nothing emptySourceCustomization Nothing sources = OMap.singleton defaultSource $ BackendSourceMetadata defaultSourceMetadata in emptyMetadata {_metaSources = sources} liftTx $ insertMetadataInCatalog emptyMetadata' pure MRInitialized -- migrates an existing catalog to the latest version from an existing verion migrateFrom :: MetadataCatalogVersion -> m MigrationResult migrateFrom previousVersion | previousVersion == latestCatalogVersion = pure MRNothingToDo | otherwise = do let upMigrations = migrations maybeDefaultSourceConfig False maintenanceMode case neededMigrations previousVersion upMigrations of [] -> throw400 NotSupported $ "Cannot use database previously used with a newer version of graphql-engine (expected" <> " a catalog version <=" <> latestCatalogVersionString <> ", but the current version" <> " is " <> tshow previousVersion <> ")." migrationsToBeApplied -> do traverse_ (mpMigrate . snd) migrationsToBeApplied updateCatalogVersion pure . MRMigrated $ tshow previousVersion where neededMigrations prevVersion upMigrations = dropWhile ((< prevVersion) . fst) upMigrations updateCatalogVersion = setCatalogVersion latestCatalogVersionString migrationTime downgradeCatalog :: forall m. (MonadIO m, MonadTx m) => Maybe (SourceConnConfiguration ('Postgres 'Vanilla)) -> DowngradeOptions -> UTCTime -> m MigrationResult downgradeCatalog defaultSourceConfig opts time = do currentCatalogVersion <- liftTx getCatalogVersion targetVersionFloat :: MetadataCatalogVersion <- onLeft (readEither (T.unpack $ dgoTargetVersion opts)) $ \err -> throw500 $ "Unexpected: couldn't convert " <> dgoTargetVersion opts <> " to a float, error: " <> tshow err downgradeFrom currentCatalogVersion targetVersionFloat where -- downgrades an existing catalog to the specified version downgradeFrom :: MetadataCatalogVersion -> MetadataCatalogVersion -> m MigrationResult downgradeFrom previousVersion targetVersion | previousVersion == targetVersion = pure MRNothingToDo | otherwise = case neededDownMigrations targetVersion of Left reason -> throw400 NotSupported $ "This downgrade path (from " <> tshow previousVersion <> " to " <> dgoTargetVersion opts <> ") is not supported, because " <> reason Right path -> do sequence_ path unless (dgoDryRun opts) do setCatalogVersion (dgoTargetVersion opts) time pure (MRMigrated (dgoTargetVersion opts)) where neededDownMigrations newVersion = downgrade previousVersion newVersion (reverse (migrations defaultSourceConfig (dgoDryRun opts) MaintenanceModeDisabled)) downgrade :: MetadataCatalogVersion -> MetadataCatalogVersion -> [(MetadataCatalogVersion, MigrationPair m)] -> Either Text [m ()] downgrade lower upper = skipFutureDowngrades where -- We find the list of downgrade scripts to run by first -- dropping any downgrades which correspond to newer versions -- of the schema than the one we're running currently. -- Then we take migrations as needed until we reach the target -- version, dropping any remaining migrations from the end of the -- (reversed) list. skipFutureDowngrades, dropOlderDowngrades :: [(MetadataCatalogVersion, MigrationPair m)] -> Either Text [m ()] skipFutureDowngrades xs | previousVersion == lower = dropOlderDowngrades xs skipFutureDowngrades [] = Left "the starting version is unrecognized." skipFutureDowngrades ((x, _) : xs) | x == lower = dropOlderDowngrades xs | otherwise = skipFutureDowngrades xs dropOlderDowngrades [] = Left "the target version is unrecognized." dropOlderDowngrades ((x, MigrationPair {mpDown = Nothing}) : _) = Left $ "there is no available migration back to version " <> tshow x <> "." dropOlderDowngrades ((x, MigrationPair {mpDown = Just y}) : xs) | x == upper = Right [y] | otherwise = (y :) <$> dropOlderDowngrades xs migrations :: forall m. (MonadIO m, MonadTx m) => Maybe (SourceConnConfiguration ('Postgres 'Vanilla)) -> Bool -> MaintenanceMode () -> [(MetadataCatalogVersion, MigrationPair m)] migrations maybeDefaultSourceConfig dryRun maintenanceMode = -- We need to build the list of migrations at compile-time so that we can compile the SQL -- directly into the executable using `Q.sqlFromFile`. The GHC stage restriction makes -- doing this a little bit awkward (we can’t use any definitions in this module at -- compile-time), but putting a `let` inside the splice itself is allowed. $( let migrationFromFile from to = let path = "src-rsr/migrations/" <> from <> "_to_" <> to <> ".sql" in [|runTxOrPrint $(makeRelativeToProject path >>= PG.sqlFromFile)|] migrationFromFileMaybe from to = do path <- makeRelativeToProject $ "src-rsr/migrations/" <> from <> "_to_" <> to <> ".sql" exists <- TH.runIO (doesFileExist path) if exists then [|Just (runTxOrPrint $(PG.sqlFromFile path))|] else [|Nothing|] migrationsFromFile = map $ \(to :: MetadataCatalogVersion) -> let from = pred to in [| ( $(TH.lift from), MigrationPair $(migrationFromFile (show from) (show to)) $(migrationFromFileMaybe (show to) (show from)) ) |] in TH.listE -- version 0.8 is the only non-integral catalog version -- The 40_to_41 migration is consciously omitted from below because its contents -- have been moved to the `0_to_1.sql` because the `40_to_41` migration only contained -- source catalog changes and we'd like to keep source catalog migrations in a different -- path than metadata catalog migrations. $ [|(MetadataCatalogVersion08, MigrationPair $(migrationFromFile "08" "1") Nothing)|] : migrationsFromFile [MetadataCatalogVersion 2 .. MetadataCatalogVersion 3] ++ [|(MetadataCatalogVersion 3, MigrationPair from3To4 Nothing)|] : (migrationsFromFile [MetadataCatalogVersion 5 .. MetadataCatalogVersion 40] ++ migrationsFromFile [MetadataCatalogVersion 42]) ++ [|(MetadataCatalogVersion 42, MigrationPair from42To43 (Just from43To42))|] : migrationsFromFile [MetadataCatalogVersion 44 .. latestCatalogVersion] ) where runTxOrPrint :: PG.Query -> m () runTxOrPrint | dryRun = liftIO . TIO.putStrLn . PG.getQueryText | otherwise = multiQ from42To43 = do when (maintenanceMode == MaintenanceModeEnabled ()) $ throw500 "cannot migrate to catalog version 43 in maintenance mode" let query = $(makeRelativeToProject "src-rsr/migrations/42_to_43.sql" >>= PG.sqlFromFile) if dryRun then (liftIO . TIO.putStrLn . PG.getQueryText) query else do metadataV2 <- fetchMetadataFromHdbTables multiQ query defaultSourceConfig <- onNothing maybeDefaultSourceConfig $ throw400 NotSupported $ "cannot migrate to catalog version 43 without --database-url or env var " <> tshow (_envVar databaseUrlOption) let metadataV3 = let MetadataNoSources {..} = metadataV2 defaultSourceMetadata = BackendSourceMetadata $ AB.mkAnyBackend $ SourceMetadata defaultSource PostgresVanillaKind _mnsTables _mnsFunctions defaultSourceConfig Nothing emptySourceCustomization Nothing in Metadata (OMap.singleton defaultSource defaultSourceMetadata) _mnsRemoteSchemas _mnsQueryCollections _mnsAllowlist _mnsCustomTypes _mnsActions _mnsCronTriggers mempty emptyApiLimit emptyMetricsConfig mempty mempty emptyNetwork mempty liftTx $ insertMetadataInCatalog metadataV3 from43To42 = do let query = $(makeRelativeToProject "src-rsr/migrations/43_to_42.sql" >>= PG.sqlFromFile) if dryRun then (liftIO . TIO.putStrLn . PG.getQueryText) query else do Metadata {..} <- liftTx fetchMetadataFromCatalog multiQ query let emptyMetadataNoSources = MetadataNoSources mempty mempty mempty mempty mempty emptyCustomTypes mempty mempty metadataV2 <- case OMap.toList _metaSources of [] -> pure emptyMetadataNoSources [(_, BackendSourceMetadata exists)] -> pure $ case AB.unpackAnyBackend exists of Nothing -> emptyMetadataNoSources Just SourceMetadata {..} -> MetadataNoSources _smTables _smFunctions _metaRemoteSchemas _metaQueryCollections _metaAllowlist _metaCustomTypes _metaActions _metaCronTriggers _ -> throw400 NotSupported "Cannot downgrade since there are more than one source" liftTx $ do flip runReaderT (SystemDefined False) $ saveMetadataToHdbTables metadataV2 -- when the graphql-engine is migrated from v1 to v2, we drop the foreign key -- constraint of the `hdb_catalog.hdb_cron_event` table because the cron triggers -- in v2 are saved in the `hdb_catalog.hdb_metadata` table. So, when a downgrade -- happens, we need to delay adding the foreign key constraint until the -- cron triggers are added in the `hdb_catalog.hdb_cron_triggers` addCronTriggerForeignKeyConstraint recreateSystemMetadata multiQ :: (MonadTx m) => PG.Query -> m () multiQ = liftTx . PG.multiQE defaultTxErrorHandler