### Description
This PR adds the ability to perform remote joins from remote schemas in the engine. To do so, we alter the definition of an `ExecutionStep` targeting a remote schema: the `ExecStepRemote` constructor now expects a `Maybe RemoteJoins`. This new argument is used when processing the execution step, in the transport layer (either `Transport.HTTP` or `Transport.WebSocket`).
For this `Maybe RemoteJoins` to be extracted from a parsed query, this PR also extends the `Execute.RemoteJoin.Collect` module, to implement "collection" from a selection set. Not only do those new functions extract the remote joins, but they also apply all necessary transformations to the selection sets (such as inserting the necessary "phantom" fields used as join keys).
Finally in `Execute.RemoteJoin.Join`, we make two changes. First, we now always look for nested remote joins, regardless of whether the join we just performed went to a source or a remote schema; and second we adapt our join tree logic according to the special cases that were added to deal with remote server edge cases.
Additionally, this PR refactors / cleans / documents `Execute.RemoteJoin.RemoteServer`. This is not required as part of this change and could be moved to a separate PR if needed (a similar cleanup of `Join` is done independently in #3894). It also introduces a draft of a new documentation page for this project, that will be refined in the release PR that ships the feature (either #3069 or a copy of it).
While this PR extends the engine, it doesn't plug such relationships in the schema, meaning that, as of this PR, the new code paths in `Join` are technically unreachable. Adding the corresponding schema code and, ultimately, enabling the metadata API will be done in subsequent PRs.
### Keeping track of concrete type names
The main change this PR makes to the existing `Join` code is to handle a new reserved field we sometimes use when targeting remote servers: the `__hasura_internal_typename` field. In short, a GraphQL selection set can sometimes "branch" based on the concrete "runtime type" of the object on which the selection happens:
```graphql
query {
author(id: 53478) {
... on Writer {
name
articles {
title
}
}
... on Artist {
name
articles {
title
}
}
}
}
```
If both of those `articles` are remote joins, we need to be able, when we get the answer, to differentiate between the two different cases. We do this by asking for `__typename`, to be able to decide if we're in the `Writer` or the `Artist` branch of the query.
To avoid further processing / customization of results, we only insert this `__hasura_internal_typename: __typename` field in the query in the case of unions of interfaces AND if we have the guarantee that we will processing the request as part of the remote joins "folding": that is, if there's any remote join in this branch in the tree. Otherwise, we don't insert the field, and we leave that part of the response untouched.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3810
GitOrigin-RevId: 89aaf16274d68e26ad3730b80c2d2fdc2896b96c
…rmance
It makes sense to try to utilize multiple threads for metadata
operations since we expect them to come one at a time (and likely at
lower load periods anyway).
As noted, although we build roles in parallel now, the admin role is
still a bottleneck. For replace_metadata on huge_schema, on my machine
I get:
BEFORE: 22.7 sec
AFTER: 13.5 sec
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3911
GitOrigin-RevId: 4d4ee6ac8b5506603e70e4fc666a3aacc054d493
### Description
Several libraries define `catMaybes` as `mapMaybe id`. We had it defined in `Data.HashMap.Strict.Extended` already. This small PR also defines it in `Extended` modules for other containers and replaces every occurrence of `mapMaybe id` accordingly.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3884
GitOrigin-RevId: d222a2ca2f4eb9b725b20450a62a626d3886dbf4
### Description
There were several places in the codebase where we would either implement a generic container, or express the need for one. This PR extracts / creates all relevant containers, and adapts the relevant parts of the code to make use of said new generic containers. More specifically, it introduces the following modules:
- `Data.Set.Extended`, for new functions on `Data.Set`
- `Data.HashMap.Strict.Multi`, for hash maps that accept multiple values
- `Data.HashMap.Strict.NonEmpty`, for hash maps that can never be constructed as empty
- `Data.Trie`, for a generic implementation of a prefix tree
This PR makes use of those new containers in the following parts of the code:
- `Hasura.GraphQL.Execute.RemoteJoin.Types`
- `Hasura.RQL.Types.Endpoint*`
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3828
GitOrigin-RevId: e6c1b971bcb3f5ab66bc91d0fa4d0e9df7a0c6c6
### Description
This PR is one further step towards remote joins from remote schemas. It introduces a custom partial AST to represent queries to remote schemas in the IR: we now need to augment what used to be a straightforward GraphQL AST with additional information for remote join fields.
This PR does the minimal amount of work to adjust the rest of the code accordingly, using `Void` in all places that expect a type representing remote relationships.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3794
GitOrigin-RevId: 33fc317731aace71f82ad158a1951ea93350d6cc
No logic in this PR, just tidying things up (renaming the backend from `Experimental` to `DataWrapper`).
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3779
GitOrigin-RevId: f11acf563ccd8b9f16bc23c5e92da392aa4cfb2c
I discovered and removed instances of Boolean Blindness about whether json numbers should be stringified or not.
Although quite far-reaching, this is a completely mechanical change and should have no observable impact outside the server code.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3763
GitOrigin-RevId: c588891afd8a6923a135c736f6581a43a2eddbc7
TL;DR
---
We go from this:
```haskell
(|
withRecordInconsistency
( (|
modifyErrA
( do
(info, dependencies) <- liftEitherA -< buildRelInfo relDef
recordDependencies -< (metadataObject, schemaObject, dependencies)
returnA -< info
)
|) (addTableContext @b table . addRelationshipContext)
)
|) metadataObject
```
to this:
```haskell
withRecordInconsistencyM metadataObject $ do
modifyErr (addTableContext @b table . addRelationshipContext) $ do
(info, dependencies) <- liftEither $ buildRelInfo relDef
recordDependenciesM metadataObject schemaObject dependencies
return info
```
Background
---
We use Haskell's `Arrows` language extension to gain some syntactic sugar when working with `Arrow`s. `Arrow`s are a programming abstraction comparable to `Monad`s.
Unfortunately the syntactic sugar provided by this language extension is not very sweet.
This PR shows how we can sometimes avoid using `Arrow`s altogether, without loss of functionality or correctness. It is a demo of a technique that can be used to cut down the amount of `Arrows`-based code in our codebase by about half.
Approach
---
Although _in general_ not every `Monad` is an `Arrow`, specific `Arrow` instantiations are exactly as powerful as their `Monad` equivalents. Otherwise they wouldn't be very equivalent, would they?
Just like `liftEither` interprets the `Either e` monad into an arbitrary monad implementing `MonadError e`, we add `interpA` which interprets certain concrete monads such as `Writer w` into specific arrows, e.g. ones satisfying `ArrowWriter w`. This means that the part of the code that only uses such interpretable effects can be written _monadically_, and then used in _arrow_ constructions down the line.
This approach cannot be used for arrow effects which do not have a monadic equivalent. In our codebase, the only instance of this is `ArrowCache m`, implemented by the `Rule m` arrow. So code written with `ArrowCache m` in the context cannot be rewritten monadically using this technique.
See also
---
- #1827
- #2210
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3543
Co-authored-by: jkachmar <8461423+jkachmar@users.noreply.github.com>
GitOrigin-RevId: eb79619c95f7a571bce99bc144ce42ee65d08505
There are three minor cleanups here:
- The first argument to the `setMetadataInCatalog` method is always `Just`. It is thus important to avoid `Maybe`, because this means that a crucial piece of code (saving metadata) is completely untested.
- Rather than spelling them out, we can derive the `Semigroup`/`Monoid` instances for `MetadataModifier` through the `Endo` type.
- I've renamed the name of the getter of the `MetadataModifier` newtype to **r**unMetadataModifier. Using record puns, this allows us to write:
```diff
- putMetadata $ unMetadataModifier metadataModifier metadata
+ putMetadata $ runMetadataModifier metadata
```
which is nicer to read.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3703
GitOrigin-RevId: fd36b3c5202017f5afc943c01dfdd7c82c099bdd
We build the GraphQL schema by combining building blocks such as `tableSelectionSet` and `columnParser`. These building blocks individually build `{InputFields,Field,}Parser` objects. Those object specify the valid GraphQL schema.
Since the GraphQL schema is role-dependent, at some point we need to know what fragment of the GraphQL schema a specific role is allowed to access, and this is stored in `{Sel,Upd,Ins,Del}PermInfo` objects.
We have passed around these permission objects as function arguments to the schema building blocks since we first started dealing with permissions during the PDV refactor - see hasura/graphql-engine@5168b99e46 in hasura/graphql-engine#4111. This means that, for instance, `tableSelectionSet` has as its type:
```haskell
tableSelectionSet ::
forall b r m n.
MonadBuildSchema b r m n =>
SourceName ->
TableInfo b ->
SelPermInfo b ->
m (Parser 'Output n (AnnotatedFields b))
```
There are three reasons to change this.
1. We often pass a `Maybe (xPermInfo b)` instead of a proper `xPermInfo b`, and it's not clear what the intended semantics of this is. Some potential improvements on the data types involved are discussed in issue hasura/graphql-engine-mono#3125.
2. In most cases we also already pass a `TableInfo b`, and together with the `MonadRole` that is usually also in scope, this means that we could look up the required permissions regardless: so passing the permissions explicitly undermines the "single source of truth" principle. Breaking this principle also makes the code more difficult to read.
3. We are working towards role-based parsers (see hasura/graphql-engine-mono#2711), where the `{InputFields,Field,}Parser` objects are constructed in a role-invariant way, so that we have a single object that can be used for all roles. In particular, this means that the schema building blocks _need_ to be constructed in a role-invariant way. While this PR doesn't accomplish that, it does reduce the amount of role-specific arguments being passed, thus fixing hasura/graphql-engine-mono#3068.
Concretely, this PR simply drops the `xPermInfo b` argument from almost all schema building blocks. Instead these objects are looked up from the `TableInfo b` as-needed. The resulting code is considerably simpler and shorter.
One way to interpret this change is as follows. Before this PR, we figured out permissions at the top-level in `Hasura.GraphQL.Schema`, passing down the obtained `xPermInfo` objects as required. After this PR, we have a bottom-up approach where the schema building blocks themselves decide whether they want to be included for a particular role.
So this moves some permission logic out of `Hasura.GraphQL.Schema`, which is very complex.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3608
GitOrigin-RevId: 51a744f34ec7d57bc8077667ae7f9cb9c4f6c962
spec: https://github.com/hasura/graphql-engine-mono/pull/2278
Briefly:
- extend metadata so that allowlist entries get a new scope field
- update `add_collection_to_allowlist` to accept this new scope field,
and adds `update_scope_of_collection_in_allowlist` to change the scope
- scope can be global or role-based; a collection is available for every
role if it is global, and available to every listed role if it is role-based
- graphql-engine-oss is aware of role-based allowlist metadata; collections
with non-global scope are treated as if they weren't in the allowlist
To run the tests:
- `cabal run graphql-engine-tests -- unit --match Allowlist`
- py-tests against pro:
- launch `graphql-engine-pro` with `HASURA_GRAPHQL_ADMIN_SECRET` and `HASURA_GRAPHQL_ENABLE_ALLOWLIST`
- `pytest test_allowlist_queries.py --hge-urls=... --pg-urls=... --hge-key=... --test-allowlist-queries --pro-tests`
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/2477
Co-authored-by: Anon Ray <616387+ecthiender@users.noreply.github.com>
Co-authored-by: Robert <132113+robx@users.noreply.github.com>
GitOrigin-RevId: 01f8026fbe59d8701e2de30986511a452fce1a99
## Description
This PR is a subset of #3069, that does roughly that #3031 was aiming to do: add the schema cache building phase for relationships from remote servers. This PR does not change any of the code that *uses* remote relationships, meaning we ignore the added schema cache information. It also contains dependency-tracking code, which was originally missing from #3031; in turn, this pulls some of the metadata API as well, since we identify remote relationships by how they were created.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3540
GitOrigin-RevId: ed962b6d07fd4adbf0a71e0d79736a4e8b422fea
## Description
This PR updates the notes-extracting script, to allow for a stable sort across runs:
- files are now treated in alphabetical order of the full file name:
- within a file, notes are treated in order
- that order is reflected in the generated index file
- within a note, references are sorted by file, then by line number
Additionally it fixes(?) a note whose format was unexpected.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3352
GitOrigin-RevId: 2b2b57ec0aa2657d75a88e4951e6b19bb2d665e3
This change is because in https://github.com/hasura/graphql-engine-mono/pull/2477, errors come out as
```
multiple declarations exist for the following allowlist : [CollectionName {unCollectionName = NonEmptyText {unNonEmptyText = "collection_1"}}]'
```
which is awfully messy. This changes it to
```
multiple declarations exist for the following allowlist: collection_1
```
This should improve error messages across the board -- e.g. `RoleName` has a nice `ToTxt` instance, while we used to use a derived `Show` instances. However, there might just be instances where the `Show` instance was better, bit hard to be sure based on scanning the code since we don't have test coverage for these errors.
Broken out of the allowlist PR since it affects more than just the allowlist.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3470
GitOrigin-RevId: 7a2c29f17d9f15d840cb2f89caefcdd3aae44d25
### Description
This PR is the result of a discussion in #3363. Namely, we would like to remove all uses of `unsafeMkName`, or at the very least document every single one of them, to avoid similar issues. To do so, this PR does the following:
- it adds a hlint suggestion not to use that function:
- suggestions don't mark the PR as failed, but will be shown at review time
- it is possible to disable that hint with `{- HLINT ignore myFunction "unsafe" -}`
- wherever possible, it removes uses of `unsafeMkName` in favour of `mkName`
- it adds a comment with a tracking issue for the two remaining uses:
- #3478
- #3479
### Remaining work
- discuss whether this hint should make the linter step fail, since the linter step isn't required to merge anyway, and there is a way to disable the hint wherever we think the use of that function is acceptable
- check that none of those uses were load-bearing and result in errors now
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3480
GitOrigin-RevId: 0a7e3e9d1a48185764c04ab61e34b58273af347c
## Description
When setting up a remote relationship to a remote schema, values coming from the left-hand side are given as _arguments_ to the targeted field of the remote schema. In turn, that means we need to adjust the arguments to that remote field; in the case of input objects, it means creating a brand new input object in which the relevant fields have been removed.
To both avoid conflicts, and be explicit, we give a pretty verbose name to such an input object: its original name, followed by "remote_rel", followed by the full name of the field (table name + relationship name). The bug there was introduced when working on extending remote relationships to other backends: we changed the code that translates the table name to a graphql identifier to be generic, and use the table's `ToTxt` instance instead. However, when a table is not in the default schema, the character used by that instance is `.`, which is not a valid GraphQL name.
This PR fixes it, by doing two things:
- it defines a safe function to translate LHS identifiers to graphql names (by replacing all invalid characters by `_`)
- it doesn't use `unsafeMkName` anymore, and checks at validation time that the type name is correct
## Further work
On this PR:
- [x] add a test
- [x] write a Changelog entry
Beyond this PR, we might want to:
- prioritize #1747
- analyze all calls to `unsafeMkName` and remove as many as possible
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3363
GitOrigin-RevId: fe98eb1d34157b2c8323af453f5c369de616af38
This commit introduces an "experimental" backend adapter to the GraphQL Engine.
It defines a high-level interface which will eventually be used as the basis for implementing separate data source query generation & marshaling services that communicate with the GraphQL Engine Server via some protocol.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/2684
Co-authored-by: awjchen <13142944+awjchen@users.noreply.github.com>
Co-authored-by: Chris Parks <592078+cdparks@users.noreply.github.com>
GitOrigin-RevId: 4463b682142ad6e069e223b88b14db511f634768
This PR pretty much does the same thing to remote relationship types in schemacache as what #2979 did to remote relationship types in the IR. On main remote relationships are represented by types of form `T from to`. This PR changes it to `T from` which makes it a lot more reusable.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3037
GitOrigin-RevId: 90a5c9e2346c8dc2da6ec5b8c970d6c863d2afb8
