graphql-engine/server/src-lib/Hasura/Server/API/Query.hs
Vamshi Surabhi e8e4f30dd6 server: support remote relationships on SQL Server and BigQuery (#1497)
Remote relationships are now supported on SQL Server and BigQuery. The major change though is the re-architecture of remote join execution logic. Prior to this PR, each backend is responsible for processing the remote relationships that are part of their AST.

This is not ideal as there is nothing specific about a remote join's execution that ties it to a backend. The only backend specific part is whether or not the specification of the remote relationship is valid (i.e, we'll need to validate whether the scalars are compatible).

The approach now changes to this:

1. Before delegating the AST to the backend, we traverse the AST, collect all the remote joins while modifying the AST to add necessary join fields where needed.

1. Once the remote joins are collected from the AST, the database call is made to fetch the response. The necessary data for the remote join(s) is collected from the database's response and one or more remote schema calls are constructed as necessary.

1. The remote schema calls are then executed and the data from the database and from the remote schemas is joined to produce the final response.

### Known issues

1. Ideally the traversal of the IR to collect remote joins should return an AST which does not include remote join fields. This operation can be type safe but isn't taken up as part of the PR.

1. There is a lot of code duplication between `Transport/HTTP.hs` and `Transport/Websocket.hs` which needs to be fixed ASAP. This too hasn't been taken up by this PR.

1. The type which represents the execution plan is only modified to handle our current remote joins and as such it will have to be changed to accommodate general remote joins.

1. Use of lenses would have reduced the boilerplate code to collect remote joins from the base AST.

1. The current remote join logic assumes that the join columns of a remote relationship appear with their names in the database response. This however is incorrect as they could be aliased. This can be taken up by anyone, I've left a comment in the code.

### Notes to the reviewers

I think it is best reviewed commit by commit.

1. The first one is very straight forward.

1. The second one refactors the remote join execution logic but other than moving things around, it doesn't change the user facing functionality.  This moves Postgres specific parts to `Backends/Postgres` module from `Execute`. Some IR related code to `Hasura.RQL.IR` module.  Simplifies various type class function signatures as a backend doesn't have to handle remote joins anymore

1. The third one fixes partial case matches that for some weird reason weren't shown as warnings before this refactor

1. The fourth one generalizes the validation logic of remote relationships and implements `scalarTypeGraphQLName` function on SQL Server and BigQuery which is used by the validation logic. This enables remote relationships on BigQuery and SQL Server.

https://github.com/hasura/graphql-engine-mono/pull/1497

GitOrigin-RevId: 77dd8eed326602b16e9a8496f52f46d22b795598
2021-06-11 03:27:39 +00:00

560 lines
21 KiB
Haskell

-- | The RQL query ('/v1/query')
module Hasura.Server.API.Query where
import Hasura.Prelude
import qualified Data.Environment as Env
import qualified Data.HashMap.Strict as HM
import qualified Database.PG.Query as Q
import qualified Network.HTTP.Client as HTTP
import Control.Monad.Trans.Control (MonadBaseControl)
import Control.Monad.Unique
import Data.Aeson
import Data.Aeson.Casing
import Data.Aeson.TH
import Network.HTTP.Client.Extended
import qualified Hasura.Tracing as Tracing
import Hasura.Backends.Postgres.DDL.RunSQL
import Hasura.Base.Error
import Hasura.EncJSON
import Hasura.Metadata.Class
import Hasura.RQL.DDL.Action
import Hasura.RQL.DDL.ComputedField
import Hasura.RQL.DDL.CustomTypes
import Hasura.RQL.DDL.Endpoint
import Hasura.RQL.DDL.EventTrigger
import Hasura.RQL.DDL.Metadata
import Hasura.RQL.DDL.Permission
import Hasura.RQL.DDL.QueryCollection
import Hasura.RQL.DDL.Relationship
import Hasura.RQL.DDL.Relationship.Rename
import Hasura.RQL.DDL.RemoteRelationship
import Hasura.RQL.DDL.RemoteSchema
import Hasura.RQL.DDL.ScheduledTrigger
import Hasura.RQL.DDL.Schema
import Hasura.RQL.DML.Count
import Hasura.RQL.DML.Delete
import Hasura.RQL.DML.Insert
import Hasura.RQL.DML.Select
import Hasura.RQL.DML.Types
import Hasura.RQL.DML.Update
import Hasura.RQL.Types
import Hasura.RQL.Types.Run
import Hasura.Server.Types
import Hasura.Server.Utils
import Hasura.Server.Version (HasVersion)
import Hasura.Session
data RQLQueryV1
= RQAddExistingTableOrView !(TrackTable ('Postgres 'Vanilla))
| RQTrackTable !(TrackTable ('Postgres 'Vanilla))
| RQUntrackTable !(UntrackTable ('Postgres 'Vanilla))
| RQSetTableIsEnum !SetTableIsEnum
| RQSetTableCustomization !SetTableCustomization
| RQTrackFunction !(TrackFunction ('Postgres 'Vanilla))
| RQUntrackFunction !(UnTrackFunction ('Postgres 'Vanilla))
| RQCreateObjectRelationship !(CreateObjRel ('Postgres 'Vanilla))
| RQCreateArrayRelationship !(CreateArrRel ('Postgres 'Vanilla))
| RQDropRelationship !(DropRel ('Postgres 'Vanilla))
| RQSetRelationshipComment !(SetRelComment ('Postgres 'Vanilla))
| RQRenameRelationship !(RenameRel ('Postgres 'Vanilla))
-- computed fields related
| RQAddComputedField !(AddComputedField ('Postgres 'Vanilla))
| RQDropComputedField !(DropComputedField ('Postgres 'Vanilla))
| RQCreateRemoteRelationship !(RemoteRelationship ('Postgres 'Vanilla))
| RQUpdateRemoteRelationship !(RemoteRelationship ('Postgres 'Vanilla))
| RQDeleteRemoteRelationship !(DeleteRemoteRelationship ('Postgres 'Vanilla))
| RQCreateInsertPermission !(CreatePerm InsPerm ('Postgres 'Vanilla))
| RQCreateSelectPermission !(CreatePerm SelPerm ('Postgres 'Vanilla))
| RQCreateUpdatePermission !(CreatePerm UpdPerm ('Postgres 'Vanilla))
| RQCreateDeletePermission !(CreatePerm DelPerm ('Postgres 'Vanilla))
| RQDropInsertPermission !(DropPerm InsPerm ('Postgres 'Vanilla))
| RQDropSelectPermission !(DropPerm SelPerm ('Postgres 'Vanilla))
| RQDropUpdatePermission !(DropPerm UpdPerm ('Postgres 'Vanilla))
| RQDropDeletePermission !(DropPerm DelPerm ('Postgres 'Vanilla))
| RQSetPermissionComment !(SetPermComment ('Postgres 'Vanilla))
| RQGetInconsistentMetadata !GetInconsistentMetadata
| RQDropInconsistentMetadata !DropInconsistentMetadata
| RQInsert !InsertQuery
| RQSelect !SelectQuery
| RQUpdate !UpdateQuery
| RQDelete !DeleteQuery
| RQCount !CountQuery
| RQBulk ![RQLQuery]
-- schema-stitching, custom resolver related
| RQAddRemoteSchema !AddRemoteSchemaQuery
| RQRemoveRemoteSchema !RemoteSchemaNameQuery
| RQReloadRemoteSchema !RemoteSchemaNameQuery
| RQIntrospectRemoteSchema !RemoteSchemaNameQuery
| RQCreateEventTrigger !(CreateEventTriggerQuery ('Postgres 'Vanilla))
| RQDeleteEventTrigger !(DeleteEventTriggerQuery ('Postgres 'Vanilla))
| RQRedeliverEvent !(RedeliverEventQuery ('Postgres 'Vanilla))
| RQInvokeEventTrigger !(InvokeEventTriggerQuery ('Postgres 'Vanilla))
-- scheduled triggers
| RQCreateCronTrigger !CreateCronTrigger
| RQDeleteCronTrigger !ScheduledTriggerName
| RQCreateScheduledEvent !CreateScheduledEvent
-- query collections, allow list related
| RQCreateQueryCollection !CreateCollection
| RQDropQueryCollection !DropCollection
| RQAddQueryToCollection !AddQueryToCollection
| RQDropQueryFromCollection !DropQueryFromCollection
| RQAddCollectionToAllowlist !CollectionReq
| RQDropCollectionFromAllowlist !CollectionReq
| RQRunSql !RunSQL
| RQReplaceMetadata !ReplaceMetadata
| RQExportMetadata !ExportMetadata
| RQClearMetadata !ClearMetadata
| RQReloadMetadata !ReloadMetadata
| RQCreateAction !CreateAction
| RQDropAction !DropAction
| RQUpdateAction !UpdateAction
| RQCreateActionPermission !CreateActionPermission
| RQDropActionPermission !DropActionPermission
| RQCreateRestEndpoint !CreateEndpoint
| RQDropRestEndpoint !DropEndpoint
| RQDumpInternalState !DumpInternalState
| RQSetCustomTypes !CustomTypes
deriving (Eq)
data RQLQueryV2
= RQV2TrackTable !(TrackTableV2 ('Postgres 'Vanilla))
| RQV2SetTableCustomFields !SetTableCustomFields -- deprecated
| RQV2TrackFunction !(TrackFunctionV2 ('Postgres 'Vanilla))
| RQV2ReplaceMetadata !ReplaceMetadataV2
deriving (Eq)
data RQLQuery
= RQV1 !RQLQueryV1
| RQV2 !RQLQueryV2
deriving (Eq)
instance FromJSON RQLQuery where
parseJSON = withObject "Object" $ \o -> do
mVersion <- o .:? "version"
let version = fromMaybe VIVersion1 mVersion
val = Object o
case version of
VIVersion1 -> RQV1 <$> parseJSON val
VIVersion2 -> RQV2 <$> parseJSON val
instance ToJSON RQLQuery where
toJSON = \case
RQV1 q -> embedVersion VIVersion1 $ toJSON q
RQV2 q -> embedVersion VIVersion2 $ toJSON q
where
embedVersion version (Object o) =
Object $ HM.insert "version" (toJSON version) o
-- never happens since JSON value of RQL queries are always objects
embedVersion _ _ = error "Unexpected: toJSON of RQL queries are not objects"
$(deriveJSON
defaultOptions { constructorTagModifier = snakeCase . drop 2
, sumEncoding = TaggedObject "type" "args"
}
''RQLQueryV1)
$(deriveJSON
defaultOptions { constructorTagModifier = snakeCase . drop 4
, sumEncoding = TaggedObject "type" "args"
, tagSingleConstructors = True
}
''RQLQueryV2
)
runQuery
:: ( HasVersion, MonadIO m, Tracing.MonadTrace m
, MonadBaseControl IO m, MonadMetadataStorage m
, MonadResolveSource m
)
=> Env.Environment
-> InstanceId
-> UserInfo -> RebuildableSchemaCache -> HTTP.Manager
-> ServerConfigCtx -> RQLQuery -> m (EncJSON, RebuildableSchemaCache)
runQuery env instanceId userInfo sc hMgr serverConfigCtx query = do
(metadata, currentResourceVersion) <- fetchMetadata
result <- runQueryM env query & Tracing.interpTraceT \x -> do
(((js, tracemeta), meta), rsc, ci) <-
x & runMetadataT metadata
& runCacheRWT sc
& peelRun runCtx
& runExceptT
& liftEitherM
pure ((js, rsc, ci, meta), tracemeta)
withReload currentResourceVersion result
where
runCtx = RunCtx userInfo hMgr serverConfigCtx
withReload currentResourceVersion (result, updatedCache, invalidations, updatedMetadata) = do
when (queryModifiesSchemaCache query) $ do
case (_sccMaintenanceMode serverConfigCtx) of
MaintenanceModeDisabled -> do
-- set modified metadata in storage
newResourceVersion <- setMetadata currentResourceVersion updatedMetadata
-- notify schema cache sync
notifySchemaCacheSync newResourceVersion instanceId invalidations
MaintenanceModeEnabled ->
throw500 "metadata cannot be modified in maintenance mode"
pure (result, updatedCache)
-- | A predicate that determines whether the given query might modify/rebuild the schema cache. If
-- so, it needs to acquire the global lock on the schema cache so that other queries do not modify
-- it concurrently.
--
-- Ideally, we would enforce this using the type system — queries for which this function returns
-- 'False' should not be allowed to modify the schema cache. But for now we just ensure consistency
-- by hand.
queryModifiesSchemaCache :: RQLQuery -> Bool
queryModifiesSchemaCache (RQV1 qi) = case qi of
RQAddExistingTableOrView _ -> True
RQTrackTable _ -> True
RQUntrackTable _ -> True
RQTrackFunction _ -> True
RQUntrackFunction _ -> True
RQSetTableIsEnum _ -> True
RQCreateObjectRelationship _ -> True
RQCreateArrayRelationship _ -> True
RQDropRelationship _ -> True
RQSetRelationshipComment _ -> False
RQRenameRelationship _ -> True
RQAddComputedField _ -> True
RQDropComputedField _ -> True
RQCreateRemoteRelationship _ -> True
RQUpdateRemoteRelationship _ -> True
RQDeleteRemoteRelationship _ -> True
RQCreateInsertPermission _ -> True
RQCreateSelectPermission _ -> True
RQCreateUpdatePermission _ -> True
RQCreateDeletePermission _ -> True
RQDropInsertPermission _ -> True
RQDropSelectPermission _ -> True
RQDropUpdatePermission _ -> True
RQDropDeletePermission _ -> True
RQSetPermissionComment _ -> False
RQGetInconsistentMetadata _ -> False
RQDropInconsistentMetadata _ -> True
RQInsert _ -> False
RQSelect _ -> False
RQUpdate _ -> False
RQDelete _ -> False
RQCount _ -> False
RQAddRemoteSchema _ -> True
RQRemoveRemoteSchema _ -> True
RQReloadRemoteSchema _ -> True
RQIntrospectRemoteSchema _ -> False
RQCreateEventTrigger _ -> True
RQDeleteEventTrigger _ -> True
RQRedeliverEvent _ -> False
RQInvokeEventTrigger _ -> False
RQCreateCronTrigger _ -> True
RQDeleteCronTrigger _ -> True
RQCreateScheduledEvent _ -> False
RQCreateQueryCollection _ -> True
RQDropQueryCollection _ -> True
RQAddQueryToCollection _ -> True
RQDropQueryFromCollection _ -> True
RQAddCollectionToAllowlist _ -> True
RQDropCollectionFromAllowlist _ -> True
RQRunSql q -> isSchemaCacheBuildRequiredRunSQL q
RQReplaceMetadata _ -> True
RQExportMetadata _ -> False
RQClearMetadata _ -> True
RQReloadMetadata _ -> True
RQCreateRestEndpoint _ -> True
RQDropRestEndpoint _ -> True
RQCreateAction _ -> True
RQDropAction _ -> True
RQUpdateAction _ -> True
RQCreateActionPermission _ -> True
RQDropActionPermission _ -> True
RQDumpInternalState _ -> False
RQSetCustomTypes _ -> True
RQSetTableCustomization _ -> True
RQBulk qs -> any queryModifiesSchemaCache qs
queryModifiesSchemaCache (RQV2 qi) = case qi of
RQV2TrackTable _ -> True
RQV2SetTableCustomFields _ -> True
RQV2TrackFunction _ -> True
RQV2ReplaceMetadata _ -> True
getQueryAccessMode :: (MonadError QErr m) => RQLQuery -> m Q.TxAccess
getQueryAccessMode q = fromMaybe Q.ReadOnly <$> getQueryAccessMode' q
where
getQueryAccessMode' ::
(MonadError QErr m) => RQLQuery -> m (Maybe Q.TxAccess)
getQueryAccessMode' (RQV1 q') =
case q' of
RQSelect _ -> pure Nothing
RQCount _ -> pure Nothing
RQRunSql RunSQL {rTxAccessMode} -> pure $ Just rTxAccessMode
RQBulk qs -> foldM reconcileAccessModeWith Nothing (zip [0 :: Integer ..] qs)
_ -> pure $ Just Q.ReadWrite
where
reconcileAccessModeWith expectedMode (i, query) = do
queryMode <- getQueryAccessMode' query
onLeft (reconcileAccessModes expectedMode queryMode) $ \errMode ->
throw400 BadRequest $
"incompatible access mode requirements in bulk query, " <>
"expected access mode: " <>
maybe "ANY" tshow expectedMode <>
" but " <>
"$.args[" <>
tshow i <>
"] forces " <>
tshow errMode
getQueryAccessMode' (RQV2 _) = pure $ Just Q.ReadWrite
-- | onRight, return reconciled access mode. onLeft, return conflicting access mode
reconcileAccessModes :: Maybe Q.TxAccess -> Maybe Q.TxAccess -> Either Q.TxAccess (Maybe Q.TxAccess)
reconcileAccessModes Nothing mode = pure mode
reconcileAccessModes mode Nothing = pure mode
reconcileAccessModes (Just mode1) (Just mode2)
| mode1 == mode2 = pure $ Just mode1
| otherwise = Left mode2
runQueryM
:: ( HasVersion, CacheRWM m, UserInfoM m
, MonadBaseControl IO m, MonadIO m, MonadUnique m
, HasHttpManagerM m
, HasServerConfigCtx m
, Tracing.MonadTrace m
, MetadataM m
, MonadMetadataStorageQueryAPI m
)
=> Env.Environment
-> RQLQuery
-> m EncJSON
runQueryM env rq = withPathK "args" $ case rq of
RQV1 q -> runQueryV1M q
RQV2 q -> runQueryV2M q
where
runQueryV1M = \case
RQAddExistingTableOrView q -> runTrackTableQ q
RQTrackTable q -> runTrackTableQ q
RQUntrackTable q -> runUntrackTableQ q
RQSetTableIsEnum q -> runSetExistingTableIsEnumQ q
RQSetTableCustomization q -> runSetTableCustomization q
RQTrackFunction q -> runTrackFunc q
RQUntrackFunction q -> runUntrackFunc q
RQCreateObjectRelationship q -> runCreateRelationship ObjRel q
RQCreateArrayRelationship q -> runCreateRelationship ArrRel q
RQDropRelationship q -> runDropRel q
RQSetRelationshipComment q -> runSetRelComment q
RQRenameRelationship q -> runRenameRel q
RQAddComputedField q -> runAddComputedField q
RQDropComputedField q -> runDropComputedField q
RQCreateInsertPermission q -> runCreatePerm q
RQCreateSelectPermission q -> runCreatePerm q
RQCreateUpdatePermission q -> runCreatePerm q
RQCreateDeletePermission q -> runCreatePerm q
RQDropInsertPermission q -> runDropPerm q
RQDropSelectPermission q -> runDropPerm q
RQDropUpdatePermission q -> runDropPerm q
RQDropDeletePermission q -> runDropPerm q
RQSetPermissionComment q -> runSetPermComment q
RQGetInconsistentMetadata q -> runGetInconsistentMetadata q
RQDropInconsistentMetadata q -> runDropInconsistentMetadata q
RQInsert q -> runInsert q
RQSelect q -> runSelect q
RQUpdate q -> runUpdate q
RQDelete q -> runDelete q
RQCount q -> runCount q
RQAddRemoteSchema q -> runAddRemoteSchema env q
RQRemoveRemoteSchema q -> runRemoveRemoteSchema q
RQReloadRemoteSchema q -> runReloadRemoteSchema q
RQIntrospectRemoteSchema q -> runIntrospectRemoteSchema q
RQCreateRemoteRelationship q -> runCreateRemoteRelationship q
RQUpdateRemoteRelationship q -> runUpdateRemoteRelationship q
RQDeleteRemoteRelationship q -> runDeleteRemoteRelationship q
RQCreateEventTrigger q -> runCreateEventTriggerQuery q
RQDeleteEventTrigger q -> runDeleteEventTriggerQuery q
RQRedeliverEvent q -> runRedeliverEvent q
RQInvokeEventTrigger q -> runInvokeEventTrigger q
RQCreateCronTrigger q -> runCreateCronTrigger q
RQDeleteCronTrigger q -> runDeleteCronTrigger q
RQCreateScheduledEvent q -> runCreateScheduledEvent q
RQCreateQueryCollection q -> runCreateCollection q
RQDropQueryCollection q -> runDropCollection q
RQAddQueryToCollection q -> runAddQueryToCollection q
RQDropQueryFromCollection q -> runDropQueryFromCollection q
RQAddCollectionToAllowlist q -> runAddCollectionToAllowlist q
RQDropCollectionFromAllowlist q -> runDropCollectionFromAllowlist q
RQReplaceMetadata q -> runReplaceMetadata q
RQClearMetadata q -> runClearMetadata q
RQExportMetadata q -> runExportMetadata q
RQReloadMetadata q -> runReloadMetadata q
RQCreateAction q -> runCreateAction q
RQDropAction q -> runDropAction q
RQUpdateAction q -> runUpdateAction q
RQCreateActionPermission q -> runCreateActionPermission q
RQDropActionPermission q -> runDropActionPermission q
RQCreateRestEndpoint q -> runCreateEndpoint q
RQDropRestEndpoint q -> runDropEndpoint q
RQDumpInternalState q -> runDumpInternalState q
RQRunSql q -> runRunSQL @'Vanilla q
RQSetCustomTypes q -> runSetCustomTypes q
RQBulk qs -> encJFromList <$> indexedMapM (runQueryM env) qs
runQueryV2M = \case
RQV2TrackTable q -> runTrackTableV2Q q
RQV2SetTableCustomFields q -> runSetTableCustomFieldsQV2 q
RQV2TrackFunction q -> runTrackFunctionV2 q
RQV2ReplaceMetadata q -> runReplaceMetadataV2 q
requiresAdmin :: RQLQuery -> Bool
requiresAdmin = \case
RQV1 q -> case q of
RQAddExistingTableOrView _ -> True
RQTrackTable _ -> True
RQUntrackTable _ -> True
RQSetTableIsEnum _ -> True
RQSetTableCustomization _ -> True
RQTrackFunction _ -> True
RQUntrackFunction _ -> True
RQCreateObjectRelationship _ -> True
RQCreateArrayRelationship _ -> True
RQDropRelationship _ -> True
RQSetRelationshipComment _ -> True
RQRenameRelationship _ -> True
RQAddComputedField _ -> True
RQDropComputedField _ -> True
RQCreateRemoteRelationship _ -> True
RQUpdateRemoteRelationship _ -> True
RQDeleteRemoteRelationship _ -> True
RQCreateInsertPermission _ -> True
RQCreateSelectPermission _ -> True
RQCreateUpdatePermission _ -> True
RQCreateDeletePermission _ -> True
RQDropInsertPermission _ -> True
RQDropSelectPermission _ -> True
RQDropUpdatePermission _ -> True
RQDropDeletePermission _ -> True
RQSetPermissionComment _ -> True
RQGetInconsistentMetadata _ -> True
RQDropInconsistentMetadata _ -> True
RQInsert _ -> False
RQSelect _ -> False
RQUpdate _ -> False
RQDelete _ -> False
RQCount _ -> False
RQAddRemoteSchema _ -> True
RQRemoveRemoteSchema _ -> True
RQReloadRemoteSchema _ -> True
RQIntrospectRemoteSchema _ -> True
RQCreateEventTrigger _ -> True
RQDeleteEventTrigger _ -> True
RQRedeliverEvent _ -> True
RQInvokeEventTrigger _ -> True
RQCreateCronTrigger _ -> True
RQDeleteCronTrigger _ -> True
RQCreateScheduledEvent _ -> True
RQCreateQueryCollection _ -> True
RQDropQueryCollection _ -> True
RQAddQueryToCollection _ -> True
RQDropQueryFromCollection _ -> True
RQAddCollectionToAllowlist _ -> True
RQDropCollectionFromAllowlist _ -> True
RQReplaceMetadata _ -> True
RQClearMetadata _ -> True
RQExportMetadata _ -> True
RQReloadMetadata _ -> True
RQCreateRestEndpoint _ -> True
RQDropRestEndpoint _ -> True
RQCreateAction _ -> True
RQDropAction _ -> True
RQUpdateAction _ -> True
RQCreateActionPermission _ -> True
RQDropActionPermission _ -> True
RQDumpInternalState _ -> True
RQSetCustomTypes _ -> True
RQRunSql _ -> True
RQBulk qs -> any requiresAdmin qs
RQV2 q -> case q of
RQV2TrackTable _ -> True
RQV2SetTableCustomFields _ -> True
RQV2TrackFunction _ -> True
RQV2ReplaceMetadata _ -> True