graphql-engine/server/src-lib/Hasura/RemoteSchema/MetadataAPI/Core.hs

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scaffolding for remote-schemas module The main aim of the PR is: 1. To set up a module structure for 'remote-schemas' package. 2. Move parts by the remote schema codebase into the new module structure to validate it. ## Notes to the reviewer Why a PR with large-ish diff? 1. We've been making progress on the MM project but we don't yet know long it is going to take us to get to the first milestone. To understand this better, we need to figure out the unknowns as soon as possible. Hence I've taken a stab at the first two items in the [end-state](https://gist.github.com/0x777/ca2bdc4284d21c3eec153b51dea255c9) document to figure out the unknowns. Unsurprisingly, there are a bunch of issues that we haven't discussed earlier. These are documented in the 'open questions' section. 1. The diff is large but that is only code moved around and I've added a section that documents how things are moved. In addition, there are fair number of PR comments to help with the review process. ## Changes in the PR ### Module structure Sets up the module structure as follows: ``` Hasura/ RemoteSchema/ Metadata/ Types.hs SchemaCache/ Types.hs Permission.hs RemoteRelationship.hs Build.hs MetadataAPI/ Types.hs Execute.hs ``` ### 1. Types representing metadata are moved Types that capture metadata information (currently scattered across several RQL modules) are moved into `Hasura.RemoteSchema.Metadata.Types`. - This new module only depends on very 'core' modules such as `Hasura.Session` for the notion of roles and `Hasura.Incremental` for `Cacheable` typeclass. - The requirement on database modules is avoided by generalizing the remote schemas metadata to accept an arbitrary 'r' for a remote relationship definition. ### 2. SchemaCache related types and build logic have been moved Types that represent remote schemas information in SchemaCache are moved into `Hasura.RemoteSchema.SchemaCache.Types`. Similar to `H.RS.Metadata.Types`, this module depends on 'core' modules except for `Hasura.GraphQL.Parser.Variable`. It has something to do with remote relationships but I haven't spent time looking into it. The validation of 'remote relationships to remote schema' is also something that needs to be looked at. Rips out the logic that builds remote schema's SchemaCache information from the monolithic `buildSchemaCacheRule` and moves it into `Hasura.RemoteSchema.SchemaCache.Build`. Further, the `.SchemaCache.Permission` and `.SchemaCache.RemoteRelationship` have been created from existing modules that capture schema cache building logic for those two components. This was a fair amount of work. On main, currently remote schema's SchemaCache information is built in two phases - in the first phase, 'permissions' and 'remote relationships' are ignored and in the second phase they are filled in. While remote relationships can only be resolved after partially resolving sources and other remote schemas, the same isn't true for permissions. Further, most of the work that is done to resolve remote relationships can be moved to the first phase so that the second phase can be a very simple traversal. This is the approach that was taken - resolve permissions and as much as remote relationships information in the first phase. ### 3. Metadata APIs related types and build logic have been moved The types that represent remote schema related metadata APIs and the execution logic have been moved to `Hasura.RemoteSchema.MetadataAPI.Types` and `.Execute` modules respectively. ## Open questions: 1. `Hasura.RemoteSchema.Metadata.Types` is so called because I was hoping that all of the metadata related APIs of remote schema can be brought in at `Hasura.RemoteSchema.Metadata.API`. However, as metadata APIs depended on functions from `SchemaCache` module (see [1](https://github.com/hasura/graphql-engine-mono/blob/ceba6d62264603ee5d279814677b29bcc43ecaea/server/src-lib/Hasura/RQL/DDL/RemoteSchema.hs#L55) and [2](https://github.com/hasura/graphql-engine-mono/blob/ceba6d62264603ee5d279814677b29bcc43ecaea/server/src-lib/Hasura/RQL/DDL/RemoteSchema.hs#L91), it made more sense to create a separate top-level module for `MetadataAPI`s. Maybe we can just have `Hasura.RemoteSchema.Metadata` and get rid of the extra nesting or have `Hasura.RemoteSchema.Metadata.{Core,Permission,RemoteRelationship}` if we want to break them down further. 1. `buildRemoteSchemas` in `H.RS.SchemaCache.Build` has the following type: ```haskell buildRemoteSchemas :: ( ArrowChoice arr, Inc.ArrowDistribute arr, ArrowWriter (Seq CollectedInfo) arr, Inc.ArrowCache m arr, MonadIO m, HasHttpManagerM m, Inc.Cacheable remoteRelationshipDefinition, ToJSON remoteRelationshipDefinition, MonadError QErr m ) => Env.Environment -> ( (Inc.Dependency (HashMap RemoteSchemaName Inc.InvalidationKey), OrderedRoles), [RemoteSchemaMetadataG remoteRelationshipDefinition] ) `arr` HashMap RemoteSchemaName (PartiallyResolvedRemoteSchemaCtxG remoteRelationshipDefinition, MetadataObject) ``` Note the dependence on `CollectedInfo` which is defined as ```haskell data CollectedInfo = CIInconsistency InconsistentMetadata | CIDependency MetadataObject -- ^ for error reporting on missing dependencies SchemaObjId SchemaDependency deriving (Eq) ``` this pretty much means that remote schemas is dependent on types from databases, actions, .... How do we fix this? Maybe introduce a typeclass such as `ArrowCollectRemoteSchemaDependencies` which is defined in `Hasura.RemoteSchema` and then implemented in graphql-engine? 1. The dependency on `buildSchemaCacheFor` in `.MetadataAPI.Execute` which has the following signature: ```haskell buildSchemaCacheFor :: (QErrM m, CacheRWM m, MetadataM m) => MetadataObjId -> MetadataModifier -> ``` This can be easily resolved if we restrict what the metadata APIs are allowed to do. Currently, they operate in an unfettered access to modify SchemaCache (the `CacheRWM` constraint): ```haskell runAddRemoteSchema :: ( QErrM m, CacheRWM m, MonadIO m, HasHttpManagerM m, MetadataM m, Tracing.MonadTrace m ) => Env.Environment -> AddRemoteSchemaQuery -> m EncJSON ``` This should instead be changed to restrict remote schema APIs to only modify remote schema metadata (but has access to the remote schemas part of the schema cache), this dependency is completely removed. ```haskell runAddRemoteSchema :: ( QErrM m, MonadIO m, HasHttpManagerM m, MonadReader RemoteSchemasSchemaCache m, MonadState RemoteSchemaMetadata m, Tracing.MonadTrace m ) => Env.Environment -> AddRemoteSchemaQuery -> m RemoteSchemeMetadataObjId ``` The idea is that the core graphql-engine would call these functions and then call `buildSchemaCacheFor`. PR-URL: https://github.com/hasura/graphql-engine-mono/pull/6291 GitOrigin-RevId: 51357148c6404afe70219afa71bd1d59bdf4ffc6
2022-10-21 06:13:07 +03:00
{-# LANGUAGE TemplateHaskell #-}
module Hasura.RemoteSchema.MetadataAPI.Core
( AddRemoteSchemaQuery (..),
RemoteSchemaNameQuery (..),
runAddRemoteSchema,
runRemoveRemoteSchema,
dropRemoteSchemaInMetadata,
runReloadRemoteSchema,
runIntrospectRemoteSchema,
dropRemoteSchemaPermissionInMetadata,
dropRemoteSchemaRemoteRelationshipInMetadata,
runUpdateRemoteSchema,
)
where
scaffolding for remote-schemas module The main aim of the PR is: 1. To set up a module structure for 'remote-schemas' package. 2. Move parts by the remote schema codebase into the new module structure to validate it. ## Notes to the reviewer Why a PR with large-ish diff? 1. We've been making progress on the MM project but we don't yet know long it is going to take us to get to the first milestone. To understand this better, we need to figure out the unknowns as soon as possible. Hence I've taken a stab at the first two items in the [end-state](https://gist.github.com/0x777/ca2bdc4284d21c3eec153b51dea255c9) document to figure out the unknowns. Unsurprisingly, there are a bunch of issues that we haven't discussed earlier. These are documented in the 'open questions' section. 1. The diff is large but that is only code moved around and I've added a section that documents how things are moved. In addition, there are fair number of PR comments to help with the review process. ## Changes in the PR ### Module structure Sets up the module structure as follows: ``` Hasura/ RemoteSchema/ Metadata/ Types.hs SchemaCache/ Types.hs Permission.hs RemoteRelationship.hs Build.hs MetadataAPI/ Types.hs Execute.hs ``` ### 1. Types representing metadata are moved Types that capture metadata information (currently scattered across several RQL modules) are moved into `Hasura.RemoteSchema.Metadata.Types`. - This new module only depends on very 'core' modules such as `Hasura.Session` for the notion of roles and `Hasura.Incremental` for `Cacheable` typeclass. - The requirement on database modules is avoided by generalizing the remote schemas metadata to accept an arbitrary 'r' for a remote relationship definition. ### 2. SchemaCache related types and build logic have been moved Types that represent remote schemas information in SchemaCache are moved into `Hasura.RemoteSchema.SchemaCache.Types`. Similar to `H.RS.Metadata.Types`, this module depends on 'core' modules except for `Hasura.GraphQL.Parser.Variable`. It has something to do with remote relationships but I haven't spent time looking into it. The validation of 'remote relationships to remote schema' is also something that needs to be looked at. Rips out the logic that builds remote schema's SchemaCache information from the monolithic `buildSchemaCacheRule` and moves it into `Hasura.RemoteSchema.SchemaCache.Build`. Further, the `.SchemaCache.Permission` and `.SchemaCache.RemoteRelationship` have been created from existing modules that capture schema cache building logic for those two components. This was a fair amount of work. On main, currently remote schema's SchemaCache information is built in two phases - in the first phase, 'permissions' and 'remote relationships' are ignored and in the second phase they are filled in. While remote relationships can only be resolved after partially resolving sources and other remote schemas, the same isn't true for permissions. Further, most of the work that is done to resolve remote relationships can be moved to the first phase so that the second phase can be a very simple traversal. This is the approach that was taken - resolve permissions and as much as remote relationships information in the first phase. ### 3. Metadata APIs related types and build logic have been moved The types that represent remote schema related metadata APIs and the execution logic have been moved to `Hasura.RemoteSchema.MetadataAPI.Types` and `.Execute` modules respectively. ## Open questions: 1. `Hasura.RemoteSchema.Metadata.Types` is so called because I was hoping that all of the metadata related APIs of remote schema can be brought in at `Hasura.RemoteSchema.Metadata.API`. However, as metadata APIs depended on functions from `SchemaCache` module (see [1](https://github.com/hasura/graphql-engine-mono/blob/ceba6d62264603ee5d279814677b29bcc43ecaea/server/src-lib/Hasura/RQL/DDL/RemoteSchema.hs#L55) and [2](https://github.com/hasura/graphql-engine-mono/blob/ceba6d62264603ee5d279814677b29bcc43ecaea/server/src-lib/Hasura/RQL/DDL/RemoteSchema.hs#L91), it made more sense to create a separate top-level module for `MetadataAPI`s. Maybe we can just have `Hasura.RemoteSchema.Metadata` and get rid of the extra nesting or have `Hasura.RemoteSchema.Metadata.{Core,Permission,RemoteRelationship}` if we want to break them down further. 1. `buildRemoteSchemas` in `H.RS.SchemaCache.Build` has the following type: ```haskell buildRemoteSchemas :: ( ArrowChoice arr, Inc.ArrowDistribute arr, ArrowWriter (Seq CollectedInfo) arr, Inc.ArrowCache m arr, MonadIO m, HasHttpManagerM m, Inc.Cacheable remoteRelationshipDefinition, ToJSON remoteRelationshipDefinition, MonadError QErr m ) => Env.Environment -> ( (Inc.Dependency (HashMap RemoteSchemaName Inc.InvalidationKey), OrderedRoles), [RemoteSchemaMetadataG remoteRelationshipDefinition] ) `arr` HashMap RemoteSchemaName (PartiallyResolvedRemoteSchemaCtxG remoteRelationshipDefinition, MetadataObject) ``` Note the dependence on `CollectedInfo` which is defined as ```haskell data CollectedInfo = CIInconsistency InconsistentMetadata | CIDependency MetadataObject -- ^ for error reporting on missing dependencies SchemaObjId SchemaDependency deriving (Eq) ``` this pretty much means that remote schemas is dependent on types from databases, actions, .... How do we fix this? Maybe introduce a typeclass such as `ArrowCollectRemoteSchemaDependencies` which is defined in `Hasura.RemoteSchema` and then implemented in graphql-engine? 1. The dependency on `buildSchemaCacheFor` in `.MetadataAPI.Execute` which has the following signature: ```haskell buildSchemaCacheFor :: (QErrM m, CacheRWM m, MetadataM m) => MetadataObjId -> MetadataModifier -> ``` This can be easily resolved if we restrict what the metadata APIs are allowed to do. Currently, they operate in an unfettered access to modify SchemaCache (the `CacheRWM` constraint): ```haskell runAddRemoteSchema :: ( QErrM m, CacheRWM m, MonadIO m, HasHttpManagerM m, MetadataM m, Tracing.MonadTrace m ) => Env.Environment -> AddRemoteSchemaQuery -> m EncJSON ``` This should instead be changed to restrict remote schema APIs to only modify remote schema metadata (but has access to the remote schemas part of the schema cache), this dependency is completely removed. ```haskell runAddRemoteSchema :: ( QErrM m, MonadIO m, HasHttpManagerM m, MonadReader RemoteSchemasSchemaCache m, MonadState RemoteSchemaMetadata m, Tracing.MonadTrace m ) => Env.Environment -> AddRemoteSchemaQuery -> m RemoteSchemeMetadataObjId ``` The idea is that the core graphql-engine would call these functions and then call `buildSchemaCacheFor`. PR-URL: https://github.com/hasura/graphql-engine-mono/pull/6291 GitOrigin-RevId: 51357148c6404afe70219afa71bd1d59bdf4ffc6
2022-10-21 06:13:07 +03:00
import Data.Aeson.TH qualified as J
import Data.Environment qualified as Env
import Data.HashMap.Strict qualified as HashMap
import Data.HashMap.Strict.InsOrd qualified as InsOrdHashMap
import Data.HashSet qualified as S
import Data.Text.Extended
import Hasura.Base.Error
2020-08-27 19:36:39 +03:00
import Hasura.EncJSON
import Hasura.GraphQL.RemoteServer
import Hasura.Prelude
import Hasura.RQL.Types.Common
import Hasura.RQL.Types.Metadata
import Hasura.RQL.Types.Metadata.Object
import Hasura.RQL.Types.Roles (RoleName)
import Hasura.RQL.Types.SchemaCache
import Hasura.RQL.Types.SchemaCache.Build
import Hasura.RQL.Types.SchemaCacheTypes
scaffolding for remote-schemas module The main aim of the PR is: 1. To set up a module structure for 'remote-schemas' package. 2. Move parts by the remote schema codebase into the new module structure to validate it. ## Notes to the reviewer Why a PR with large-ish diff? 1. We've been making progress on the MM project but we don't yet know long it is going to take us to get to the first milestone. To understand this better, we need to figure out the unknowns as soon as possible. Hence I've taken a stab at the first two items in the [end-state](https://gist.github.com/0x777/ca2bdc4284d21c3eec153b51dea255c9) document to figure out the unknowns. Unsurprisingly, there are a bunch of issues that we haven't discussed earlier. These are documented in the 'open questions' section. 1. The diff is large but that is only code moved around and I've added a section that documents how things are moved. In addition, there are fair number of PR comments to help with the review process. ## Changes in the PR ### Module structure Sets up the module structure as follows: ``` Hasura/ RemoteSchema/ Metadata/ Types.hs SchemaCache/ Types.hs Permission.hs RemoteRelationship.hs Build.hs MetadataAPI/ Types.hs Execute.hs ``` ### 1. Types representing metadata are moved Types that capture metadata information (currently scattered across several RQL modules) are moved into `Hasura.RemoteSchema.Metadata.Types`. - This new module only depends on very 'core' modules such as `Hasura.Session` for the notion of roles and `Hasura.Incremental` for `Cacheable` typeclass. - The requirement on database modules is avoided by generalizing the remote schemas metadata to accept an arbitrary 'r' for a remote relationship definition. ### 2. SchemaCache related types and build logic have been moved Types that represent remote schemas information in SchemaCache are moved into `Hasura.RemoteSchema.SchemaCache.Types`. Similar to `H.RS.Metadata.Types`, this module depends on 'core' modules except for `Hasura.GraphQL.Parser.Variable`. It has something to do with remote relationships but I haven't spent time looking into it. The validation of 'remote relationships to remote schema' is also something that needs to be looked at. Rips out the logic that builds remote schema's SchemaCache information from the monolithic `buildSchemaCacheRule` and moves it into `Hasura.RemoteSchema.SchemaCache.Build`. Further, the `.SchemaCache.Permission` and `.SchemaCache.RemoteRelationship` have been created from existing modules that capture schema cache building logic for those two components. This was a fair amount of work. On main, currently remote schema's SchemaCache information is built in two phases - in the first phase, 'permissions' and 'remote relationships' are ignored and in the second phase they are filled in. While remote relationships can only be resolved after partially resolving sources and other remote schemas, the same isn't true for permissions. Further, most of the work that is done to resolve remote relationships can be moved to the first phase so that the second phase can be a very simple traversal. This is the approach that was taken - resolve permissions and as much as remote relationships information in the first phase. ### 3. Metadata APIs related types and build logic have been moved The types that represent remote schema related metadata APIs and the execution logic have been moved to `Hasura.RemoteSchema.MetadataAPI.Types` and `.Execute` modules respectively. ## Open questions: 1. `Hasura.RemoteSchema.Metadata.Types` is so called because I was hoping that all of the metadata related APIs of remote schema can be brought in at `Hasura.RemoteSchema.Metadata.API`. However, as metadata APIs depended on functions from `SchemaCache` module (see [1](https://github.com/hasura/graphql-engine-mono/blob/ceba6d62264603ee5d279814677b29bcc43ecaea/server/src-lib/Hasura/RQL/DDL/RemoteSchema.hs#L55) and [2](https://github.com/hasura/graphql-engine-mono/blob/ceba6d62264603ee5d279814677b29bcc43ecaea/server/src-lib/Hasura/RQL/DDL/RemoteSchema.hs#L91), it made more sense to create a separate top-level module for `MetadataAPI`s. Maybe we can just have `Hasura.RemoteSchema.Metadata` and get rid of the extra nesting or have `Hasura.RemoteSchema.Metadata.{Core,Permission,RemoteRelationship}` if we want to break them down further. 1. `buildRemoteSchemas` in `H.RS.SchemaCache.Build` has the following type: ```haskell buildRemoteSchemas :: ( ArrowChoice arr, Inc.ArrowDistribute arr, ArrowWriter (Seq CollectedInfo) arr, Inc.ArrowCache m arr, MonadIO m, HasHttpManagerM m, Inc.Cacheable remoteRelationshipDefinition, ToJSON remoteRelationshipDefinition, MonadError QErr m ) => Env.Environment -> ( (Inc.Dependency (HashMap RemoteSchemaName Inc.InvalidationKey), OrderedRoles), [RemoteSchemaMetadataG remoteRelationshipDefinition] ) `arr` HashMap RemoteSchemaName (PartiallyResolvedRemoteSchemaCtxG remoteRelationshipDefinition, MetadataObject) ``` Note the dependence on `CollectedInfo` which is defined as ```haskell data CollectedInfo = CIInconsistency InconsistentMetadata | CIDependency MetadataObject -- ^ for error reporting on missing dependencies SchemaObjId SchemaDependency deriving (Eq) ``` this pretty much means that remote schemas is dependent on types from databases, actions, .... How do we fix this? Maybe introduce a typeclass such as `ArrowCollectRemoteSchemaDependencies` which is defined in `Hasura.RemoteSchema` and then implemented in graphql-engine? 1. The dependency on `buildSchemaCacheFor` in `.MetadataAPI.Execute` which has the following signature: ```haskell buildSchemaCacheFor :: (QErrM m, CacheRWM m, MetadataM m) => MetadataObjId -> MetadataModifier -> ``` This can be easily resolved if we restrict what the metadata APIs are allowed to do. Currently, they operate in an unfettered access to modify SchemaCache (the `CacheRWM` constraint): ```haskell runAddRemoteSchema :: ( QErrM m, CacheRWM m, MonadIO m, HasHttpManagerM m, MetadataM m, Tracing.MonadTrace m ) => Env.Environment -> AddRemoteSchemaQuery -> m EncJSON ``` This should instead be changed to restrict remote schema APIs to only modify remote schema metadata (but has access to the remote schemas part of the schema cache), this dependency is completely removed. ```haskell runAddRemoteSchema :: ( QErrM m, MonadIO m, HasHttpManagerM m, MonadReader RemoteSchemasSchemaCache m, MonadState RemoteSchemaMetadata m, Tracing.MonadTrace m ) => Env.Environment -> AddRemoteSchemaQuery -> m RemoteSchemeMetadataObjId ``` The idea is that the core graphql-engine would call these functions and then call `buildSchemaCacheFor`. PR-URL: https://github.com/hasura/graphql-engine-mono/pull/6291 GitOrigin-RevId: 51357148c6404afe70219afa71bd1d59bdf4ffc6
2022-10-21 06:13:07 +03:00
import Hasura.RemoteSchema.Metadata
import Hasura.RemoteSchema.SchemaCache.Build (addRemoteSchemaP2Setup)
import Hasura.RemoteSchema.SchemaCache.Types
harmonize network manager handling ## Description ### I want to speak to the `Manager` Oh boy. This PR is both fairly straightforward and overreaching, so let's break it down. For most network access, we need a [`HTTP.Manager`](https://hackage.haskell.org/package/http-client-0.1.0.0/docs/Network-HTTP-Client-Manager.html). It is created only once, at the top level, when starting the engine, and is then threaded through the application to wherever we need to make a network call. As of main, the way we do this is not standardized: most of the GraphQL execution code passes it "manually" as a function argument throughout the code. We also have a custom monad constraint, `HasHttpManagerM`, that describes a monad's ability to provide a manager. And, finally, several parts of the code store the manager in some kind of argument structure, such as `RunT`'s `RunCtx`. This PR's first goal is to harmonize all of this: we always create the manager at the root, and we already have it when we do our very first `runReaderT`. Wouldn't it make sense for the rest of the code to not manually pass it anywhere, to not store it anywhere, but to always rely on the current monad providing it? This is, in short, what this PR does: it implements a constraint on the base monads, so that they provide the manager, and removes most explicit passing from the code. ### First come, first served One way this PR goes a tiny bit further than "just" doing the aforementioned harmonization is that it starts the process of implementing the "Services oriented architecture" roughly outlined in this [draft document](https://docs.google.com/document/d/1FAigqrST0juU1WcT4HIxJxe1iEBwTuBZodTaeUvsKqQ/edit?usp=sharing). Instead of using the existing `HasHTTPManagerM`, this PR revamps it into the `ProvidesNetwork` service. The idea is, again, that we should make all "external" dependencies of the engine, all things that the core of the engine doesn't care about, a "service". This allows us to define clear APIs for features, to choose different implementations based on which version of the engine we're running, harmonizes our many scattered monadic constraints... Which is why this service is called "Network": we can refine it, moving forward, to be the constraint that defines how all network communication is to operate, instead of relying on disparate classes constraint or hardcoded decisions. A comment in the code clarifies this intent. ### Side-effects? In my Haskell? This PR also unavoidably touches some other aspects of the codebase. One such example: it introduces `Hasura.App.AppContext`, named after `HasuraPro.Context.AppContext`: a name for the reader structure at the base level. It also transforms `Handler` from a type alias to a newtype, as `Handler` is where we actually enforce HTTP limits; but without `Handler` being a distinct type, any code path could simply do a `runExceptT $ runReader` and forget to enforce them. (As a rule of thumb, i am starting to consider any straggling `runReaderT` or `runExceptT` as a code smell: we should not stack / unstack monads haphazardly, and every layer should be an opaque `newtype` with a corresponding run function.) ## Further work In several places, i have left TODOs when i have encountered things that suggest that we should do further unrelated cleanups. I'll write down the follow-up steps, either in the aforementioned document or on slack. But, in short, at a glance, in approximate order, we could: - delete `ExecutionCtx` as it is only a subset of `ServerCtx`, and remove one more `runReaderT` call - delete `ServerConfigCtx` as it is only a subset of `ServerCtx`, and remove it from `RunCtx` - remove `ServerCtx` from `HandlerCtx`, and make it part of `AppContext`, or even make it the `AppContext` altogether (since, at least for the OSS version, `AppContext` is there again only a subset) - remove `CacheBuildParams` and `CacheBuild` altogether, as they're just a distinct stack that is a `ReaderT` on top of `IO` that contains, you guessed it, the same thing as `ServerCtx` - move `RunT` out of `RQL.Types` and rename it, since after the previous cleanups **it only contains `UserInfo`**; it could be bundled with the authentication service, made a small implementation detail in `Hasura.Server.Auth` - rename `PGMetadaStorageT` to something a bit more accurate, such as `App`, and enforce its IO base This would significantly simply our complex stack. From there, or in parallel, we can start moving existing dependencies as Services. For the purpose of supporting read replicas entitlement, we could move `MonadResolveSource` to a `SourceResolver` service, as attempted in #7653, and transform `UserAuthenticationM` into a `Authentication` service. PR-URL: https://github.com/hasura/graphql-engine-mono/pull/7736 GitOrigin-RevId: 68cce710eb9e7d752bda1ba0c49541d24df8209f
2023-02-22 18:53:52 +03:00
import Hasura.Services
import Hasura.Session (UserInfoM)
import Hasura.Tracing qualified as Tracing
scaffolding for remote-schemas module The main aim of the PR is: 1. To set up a module structure for 'remote-schemas' package. 2. Move parts by the remote schema codebase into the new module structure to validate it. ## Notes to the reviewer Why a PR with large-ish diff? 1. We've been making progress on the MM project but we don't yet know long it is going to take us to get to the first milestone. To understand this better, we need to figure out the unknowns as soon as possible. Hence I've taken a stab at the first two items in the [end-state](https://gist.github.com/0x777/ca2bdc4284d21c3eec153b51dea255c9) document to figure out the unknowns. Unsurprisingly, there are a bunch of issues that we haven't discussed earlier. These are documented in the 'open questions' section. 1. The diff is large but that is only code moved around and I've added a section that documents how things are moved. In addition, there are fair number of PR comments to help with the review process. ## Changes in the PR ### Module structure Sets up the module structure as follows: ``` Hasura/ RemoteSchema/ Metadata/ Types.hs SchemaCache/ Types.hs Permission.hs RemoteRelationship.hs Build.hs MetadataAPI/ Types.hs Execute.hs ``` ### 1. Types representing metadata are moved Types that capture metadata information (currently scattered across several RQL modules) are moved into `Hasura.RemoteSchema.Metadata.Types`. - This new module only depends on very 'core' modules such as `Hasura.Session` for the notion of roles and `Hasura.Incremental` for `Cacheable` typeclass. - The requirement on database modules is avoided by generalizing the remote schemas metadata to accept an arbitrary 'r' for a remote relationship definition. ### 2. SchemaCache related types and build logic have been moved Types that represent remote schemas information in SchemaCache are moved into `Hasura.RemoteSchema.SchemaCache.Types`. Similar to `H.RS.Metadata.Types`, this module depends on 'core' modules except for `Hasura.GraphQL.Parser.Variable`. It has something to do with remote relationships but I haven't spent time looking into it. The validation of 'remote relationships to remote schema' is also something that needs to be looked at. Rips out the logic that builds remote schema's SchemaCache information from the monolithic `buildSchemaCacheRule` and moves it into `Hasura.RemoteSchema.SchemaCache.Build`. Further, the `.SchemaCache.Permission` and `.SchemaCache.RemoteRelationship` have been created from existing modules that capture schema cache building logic for those two components. This was a fair amount of work. On main, currently remote schema's SchemaCache information is built in two phases - in the first phase, 'permissions' and 'remote relationships' are ignored and in the second phase they are filled in. While remote relationships can only be resolved after partially resolving sources and other remote schemas, the same isn't true for permissions. Further, most of the work that is done to resolve remote relationships can be moved to the first phase so that the second phase can be a very simple traversal. This is the approach that was taken - resolve permissions and as much as remote relationships information in the first phase. ### 3. Metadata APIs related types and build logic have been moved The types that represent remote schema related metadata APIs and the execution logic have been moved to `Hasura.RemoteSchema.MetadataAPI.Types` and `.Execute` modules respectively. ## Open questions: 1. `Hasura.RemoteSchema.Metadata.Types` is so called because I was hoping that all of the metadata related APIs of remote schema can be brought in at `Hasura.RemoteSchema.Metadata.API`. However, as metadata APIs depended on functions from `SchemaCache` module (see [1](https://github.com/hasura/graphql-engine-mono/blob/ceba6d62264603ee5d279814677b29bcc43ecaea/server/src-lib/Hasura/RQL/DDL/RemoteSchema.hs#L55) and [2](https://github.com/hasura/graphql-engine-mono/blob/ceba6d62264603ee5d279814677b29bcc43ecaea/server/src-lib/Hasura/RQL/DDL/RemoteSchema.hs#L91), it made more sense to create a separate top-level module for `MetadataAPI`s. Maybe we can just have `Hasura.RemoteSchema.Metadata` and get rid of the extra nesting or have `Hasura.RemoteSchema.Metadata.{Core,Permission,RemoteRelationship}` if we want to break them down further. 1. `buildRemoteSchemas` in `H.RS.SchemaCache.Build` has the following type: ```haskell buildRemoteSchemas :: ( ArrowChoice arr, Inc.ArrowDistribute arr, ArrowWriter (Seq CollectedInfo) arr, Inc.ArrowCache m arr, MonadIO m, HasHttpManagerM m, Inc.Cacheable remoteRelationshipDefinition, ToJSON remoteRelationshipDefinition, MonadError QErr m ) => Env.Environment -> ( (Inc.Dependency (HashMap RemoteSchemaName Inc.InvalidationKey), OrderedRoles), [RemoteSchemaMetadataG remoteRelationshipDefinition] ) `arr` HashMap RemoteSchemaName (PartiallyResolvedRemoteSchemaCtxG remoteRelationshipDefinition, MetadataObject) ``` Note the dependence on `CollectedInfo` which is defined as ```haskell data CollectedInfo = CIInconsistency InconsistentMetadata | CIDependency MetadataObject -- ^ for error reporting on missing dependencies SchemaObjId SchemaDependency deriving (Eq) ``` this pretty much means that remote schemas is dependent on types from databases, actions, .... How do we fix this? Maybe introduce a typeclass such as `ArrowCollectRemoteSchemaDependencies` which is defined in `Hasura.RemoteSchema` and then implemented in graphql-engine? 1. The dependency on `buildSchemaCacheFor` in `.MetadataAPI.Execute` which has the following signature: ```haskell buildSchemaCacheFor :: (QErrM m, CacheRWM m, MetadataM m) => MetadataObjId -> MetadataModifier -> ``` This can be easily resolved if we restrict what the metadata APIs are allowed to do. Currently, they operate in an unfettered access to modify SchemaCache (the `CacheRWM` constraint): ```haskell runAddRemoteSchema :: ( QErrM m, CacheRWM m, MonadIO m, HasHttpManagerM m, MetadataM m, Tracing.MonadTrace m ) => Env.Environment -> AddRemoteSchemaQuery -> m EncJSON ``` This should instead be changed to restrict remote schema APIs to only modify remote schema metadata (but has access to the remote schemas part of the schema cache), this dependency is completely removed. ```haskell runAddRemoteSchema :: ( QErrM m, MonadIO m, HasHttpManagerM m, MonadReader RemoteSchemasSchemaCache m, MonadState RemoteSchemaMetadata m, Tracing.MonadTrace m ) => Env.Environment -> AddRemoteSchemaQuery -> m RemoteSchemeMetadataObjId ``` The idea is that the core graphql-engine would call these functions and then call `buildSchemaCacheFor`. PR-URL: https://github.com/hasura/graphql-engine-mono/pull/6291 GitOrigin-RevId: 51357148c6404afe70219afa71bd1d59bdf4ffc6
2022-10-21 06:13:07 +03:00
-- | The payload for 'add_remote_schema', and a component of 'Metadata'.
data AddRemoteSchemaQuery = AddRemoteSchemaQuery
{ -- | An internal identifier for this remote schema.
_arsqName :: RemoteSchemaName,
_arsqDefinition :: RemoteSchemaDef,
-- | An opaque description or comment. We might display this in the UI, for instance.
_arsqComment :: Maybe Text
}
deriving (Show, Eq, Generic)
instance NFData AddRemoteSchemaQuery
$(J.deriveJSON hasuraJSON ''AddRemoteSchemaQuery)
newtype RemoteSchemaNameQuery = RemoteSchemaNameQuery
{ _rsnqName :: RemoteSchemaName
}
deriving (Show, Eq)
$(J.deriveJSON hasuraJSON ''RemoteSchemaNameQuery)
runAddRemoteSchema ::
( QErrM m,
CacheRWM m,
MonadIO m,
harmonize network manager handling ## Description ### I want to speak to the `Manager` Oh boy. This PR is both fairly straightforward and overreaching, so let's break it down. For most network access, we need a [`HTTP.Manager`](https://hackage.haskell.org/package/http-client-0.1.0.0/docs/Network-HTTP-Client-Manager.html). It is created only once, at the top level, when starting the engine, and is then threaded through the application to wherever we need to make a network call. As of main, the way we do this is not standardized: most of the GraphQL execution code passes it "manually" as a function argument throughout the code. We also have a custom monad constraint, `HasHttpManagerM`, that describes a monad's ability to provide a manager. And, finally, several parts of the code store the manager in some kind of argument structure, such as `RunT`'s `RunCtx`. This PR's first goal is to harmonize all of this: we always create the manager at the root, and we already have it when we do our very first `runReaderT`. Wouldn't it make sense for the rest of the code to not manually pass it anywhere, to not store it anywhere, but to always rely on the current monad providing it? This is, in short, what this PR does: it implements a constraint on the base monads, so that they provide the manager, and removes most explicit passing from the code. ### First come, first served One way this PR goes a tiny bit further than "just" doing the aforementioned harmonization is that it starts the process of implementing the "Services oriented architecture" roughly outlined in this [draft document](https://docs.google.com/document/d/1FAigqrST0juU1WcT4HIxJxe1iEBwTuBZodTaeUvsKqQ/edit?usp=sharing). Instead of using the existing `HasHTTPManagerM`, this PR revamps it into the `ProvidesNetwork` service. The idea is, again, that we should make all "external" dependencies of the engine, all things that the core of the engine doesn't care about, a "service". This allows us to define clear APIs for features, to choose different implementations based on which version of the engine we're running, harmonizes our many scattered monadic constraints... Which is why this service is called "Network": we can refine it, moving forward, to be the constraint that defines how all network communication is to operate, instead of relying on disparate classes constraint or hardcoded decisions. A comment in the code clarifies this intent. ### Side-effects? In my Haskell? This PR also unavoidably touches some other aspects of the codebase. One such example: it introduces `Hasura.App.AppContext`, named after `HasuraPro.Context.AppContext`: a name for the reader structure at the base level. It also transforms `Handler` from a type alias to a newtype, as `Handler` is where we actually enforce HTTP limits; but without `Handler` being a distinct type, any code path could simply do a `runExceptT $ runReader` and forget to enforce them. (As a rule of thumb, i am starting to consider any straggling `runReaderT` or `runExceptT` as a code smell: we should not stack / unstack monads haphazardly, and every layer should be an opaque `newtype` with a corresponding run function.) ## Further work In several places, i have left TODOs when i have encountered things that suggest that we should do further unrelated cleanups. I'll write down the follow-up steps, either in the aforementioned document or on slack. But, in short, at a glance, in approximate order, we could: - delete `ExecutionCtx` as it is only a subset of `ServerCtx`, and remove one more `runReaderT` call - delete `ServerConfigCtx` as it is only a subset of `ServerCtx`, and remove it from `RunCtx` - remove `ServerCtx` from `HandlerCtx`, and make it part of `AppContext`, or even make it the `AppContext` altogether (since, at least for the OSS version, `AppContext` is there again only a subset) - remove `CacheBuildParams` and `CacheBuild` altogether, as they're just a distinct stack that is a `ReaderT` on top of `IO` that contains, you guessed it, the same thing as `ServerCtx` - move `RunT` out of `RQL.Types` and rename it, since after the previous cleanups **it only contains `UserInfo`**; it could be bundled with the authentication service, made a small implementation detail in `Hasura.Server.Auth` - rename `PGMetadaStorageT` to something a bit more accurate, such as `App`, and enforce its IO base This would significantly simply our complex stack. From there, or in parallel, we can start moving existing dependencies as Services. For the purpose of supporting read replicas entitlement, we could move `MonadResolveSource` to a `SourceResolver` service, as attempted in #7653, and transform `UserAuthenticationM` into a `Authentication` service. PR-URL: https://github.com/hasura/graphql-engine-mono/pull/7736 GitOrigin-RevId: 68cce710eb9e7d752bda1ba0c49541d24df8209f
2023-02-22 18:53:52 +03:00
ProvidesNetwork m,
MetadataM m,
Tracing.MonadTrace m
) =>
Env.Environment ->
AddRemoteSchemaQuery ->
m EncJSON
scaffolding for remote-schemas module The main aim of the PR is: 1. To set up a module structure for 'remote-schemas' package. 2. Move parts by the remote schema codebase into the new module structure to validate it. ## Notes to the reviewer Why a PR with large-ish diff? 1. We've been making progress on the MM project but we don't yet know long it is going to take us to get to the first milestone. To understand this better, we need to figure out the unknowns as soon as possible. Hence I've taken a stab at the first two items in the [end-state](https://gist.github.com/0x777/ca2bdc4284d21c3eec153b51dea255c9) document to figure out the unknowns. Unsurprisingly, there are a bunch of issues that we haven't discussed earlier. These are documented in the 'open questions' section. 1. The diff is large but that is only code moved around and I've added a section that documents how things are moved. In addition, there are fair number of PR comments to help with the review process. ## Changes in the PR ### Module structure Sets up the module structure as follows: ``` Hasura/ RemoteSchema/ Metadata/ Types.hs SchemaCache/ Types.hs Permission.hs RemoteRelationship.hs Build.hs MetadataAPI/ Types.hs Execute.hs ``` ### 1. Types representing metadata are moved Types that capture metadata information (currently scattered across several RQL modules) are moved into `Hasura.RemoteSchema.Metadata.Types`. - This new module only depends on very 'core' modules such as `Hasura.Session` for the notion of roles and `Hasura.Incremental` for `Cacheable` typeclass. - The requirement on database modules is avoided by generalizing the remote schemas metadata to accept an arbitrary 'r' for a remote relationship definition. ### 2. SchemaCache related types and build logic have been moved Types that represent remote schemas information in SchemaCache are moved into `Hasura.RemoteSchema.SchemaCache.Types`. Similar to `H.RS.Metadata.Types`, this module depends on 'core' modules except for `Hasura.GraphQL.Parser.Variable`. It has something to do with remote relationships but I haven't spent time looking into it. The validation of 'remote relationships to remote schema' is also something that needs to be looked at. Rips out the logic that builds remote schema's SchemaCache information from the monolithic `buildSchemaCacheRule` and moves it into `Hasura.RemoteSchema.SchemaCache.Build`. Further, the `.SchemaCache.Permission` and `.SchemaCache.RemoteRelationship` have been created from existing modules that capture schema cache building logic for those two components. This was a fair amount of work. On main, currently remote schema's SchemaCache information is built in two phases - in the first phase, 'permissions' and 'remote relationships' are ignored and in the second phase they are filled in. While remote relationships can only be resolved after partially resolving sources and other remote schemas, the same isn't true for permissions. Further, most of the work that is done to resolve remote relationships can be moved to the first phase so that the second phase can be a very simple traversal. This is the approach that was taken - resolve permissions and as much as remote relationships information in the first phase. ### 3. Metadata APIs related types and build logic have been moved The types that represent remote schema related metadata APIs and the execution logic have been moved to `Hasura.RemoteSchema.MetadataAPI.Types` and `.Execute` modules respectively. ## Open questions: 1. `Hasura.RemoteSchema.Metadata.Types` is so called because I was hoping that all of the metadata related APIs of remote schema can be brought in at `Hasura.RemoteSchema.Metadata.API`. However, as metadata APIs depended on functions from `SchemaCache` module (see [1](https://github.com/hasura/graphql-engine-mono/blob/ceba6d62264603ee5d279814677b29bcc43ecaea/server/src-lib/Hasura/RQL/DDL/RemoteSchema.hs#L55) and [2](https://github.com/hasura/graphql-engine-mono/blob/ceba6d62264603ee5d279814677b29bcc43ecaea/server/src-lib/Hasura/RQL/DDL/RemoteSchema.hs#L91), it made more sense to create a separate top-level module for `MetadataAPI`s. Maybe we can just have `Hasura.RemoteSchema.Metadata` and get rid of the extra nesting or have `Hasura.RemoteSchema.Metadata.{Core,Permission,RemoteRelationship}` if we want to break them down further. 1. `buildRemoteSchemas` in `H.RS.SchemaCache.Build` has the following type: ```haskell buildRemoteSchemas :: ( ArrowChoice arr, Inc.ArrowDistribute arr, ArrowWriter (Seq CollectedInfo) arr, Inc.ArrowCache m arr, MonadIO m, HasHttpManagerM m, Inc.Cacheable remoteRelationshipDefinition, ToJSON remoteRelationshipDefinition, MonadError QErr m ) => Env.Environment -> ( (Inc.Dependency (HashMap RemoteSchemaName Inc.InvalidationKey), OrderedRoles), [RemoteSchemaMetadataG remoteRelationshipDefinition] ) `arr` HashMap RemoteSchemaName (PartiallyResolvedRemoteSchemaCtxG remoteRelationshipDefinition, MetadataObject) ``` Note the dependence on `CollectedInfo` which is defined as ```haskell data CollectedInfo = CIInconsistency InconsistentMetadata | CIDependency MetadataObject -- ^ for error reporting on missing dependencies SchemaObjId SchemaDependency deriving (Eq) ``` this pretty much means that remote schemas is dependent on types from databases, actions, .... How do we fix this? Maybe introduce a typeclass such as `ArrowCollectRemoteSchemaDependencies` which is defined in `Hasura.RemoteSchema` and then implemented in graphql-engine? 1. The dependency on `buildSchemaCacheFor` in `.MetadataAPI.Execute` which has the following signature: ```haskell buildSchemaCacheFor :: (QErrM m, CacheRWM m, MetadataM m) => MetadataObjId -> MetadataModifier -> ``` This can be easily resolved if we restrict what the metadata APIs are allowed to do. Currently, they operate in an unfettered access to modify SchemaCache (the `CacheRWM` constraint): ```haskell runAddRemoteSchema :: ( QErrM m, CacheRWM m, MonadIO m, HasHttpManagerM m, MetadataM m, Tracing.MonadTrace m ) => Env.Environment -> AddRemoteSchemaQuery -> m EncJSON ``` This should instead be changed to restrict remote schema APIs to only modify remote schema metadata (but has access to the remote schemas part of the schema cache), this dependency is completely removed. ```haskell runAddRemoteSchema :: ( QErrM m, MonadIO m, HasHttpManagerM m, MonadReader RemoteSchemasSchemaCache m, MonadState RemoteSchemaMetadata m, Tracing.MonadTrace m ) => Env.Environment -> AddRemoteSchemaQuery -> m RemoteSchemeMetadataObjId ``` The idea is that the core graphql-engine would call these functions and then call `buildSchemaCacheFor`. PR-URL: https://github.com/hasura/graphql-engine-mono/pull/6291 GitOrigin-RevId: 51357148c6404afe70219afa71bd1d59bdf4ffc6
2022-10-21 06:13:07 +03:00
runAddRemoteSchema env (AddRemoteSchemaQuery name defn comment) = do
addRemoteSchemaP1 name
void $ addRemoteSchemaP2Setup env defn
buildSchemaCacheFor (MORemoteSchema name)
$ MetadataModifier
$ metaRemoteSchemas
%~ InsOrdHashMap.insert name remoteSchemaMeta
pure successMsg
where
-- NOTE: permissions here are empty, manipulated via a separate API with
-- runAddRemoteSchemaPermissions below
remoteSchemaMeta = RemoteSchemaMetadata name defn comment mempty mempty
addRemoteSchemaP1 ::
(QErrM m, CacheRM m) =>
RemoteSchemaName ->
m ()
addRemoteSchemaP1 name = do
remoteSchemaNames <- getAllRemoteSchemas <$> askSchemaCache
when (name `elem` remoteSchemaNames)
$ throw400 AlreadyExists
$ "remote schema with name "
<> name
<<> " already exists"
runRemoveRemoteSchema ::
(QErrM m, UserInfoM m, CacheRWM m, MetadataM m) =>
RemoteSchemaNameQuery ->
m EncJSON
runRemoveRemoteSchema (RemoteSchemaNameQuery rsn) = do
void $ removeRemoteSchemaP1 rsn
withNewInconsistentObjsCheck
$ buildSchemaCache
$ dropRemoteSchemaInMetadata rsn
pure successMsg
removeRemoteSchemaP1 ::
(UserInfoM m, QErrM m, CacheRM m) =>
RemoteSchemaName ->
m [RoleName]
removeRemoteSchemaP1 rsn = do
sc <- askSchemaCache
let rmSchemas = scRemoteSchemas sc
void
$ onNothing (HashMap.lookup rsn rmSchemas)
$ throw400 NotExists "no such remote schema"
let depObjs = getDependentObjs sc remoteSchemaDepId
roles = mapMaybe getRole depObjs
nonPermDependentObjs = filter nonPermDependentObjPredicate depObjs
-- report non permission dependencies (if any), this happens
-- mostly when a remote relationship is defined with
-- the current remote schema
-- we only report the non permission dependencies because we
-- drop the related permissions
server/mssql: add cascade to mssql_run_sql <!-- Thank you for ss in the Title above ^ --> ## Description <!-- Please fill thier. --> <!-- Describe the changes from a user's perspective --> We don't have dependency reporting mechanism for `mssql_run_sql` API i.e when a database object (table, column etc.) is dropped through the API we should raise an exception if any dependencies (relationships, permissions etc.) with the database object exists in the metadata. This PR addresses the above mentioned problem by -> Integrating transaction to the API to rollback the SQL query execution if dependencies exists and exception is thrown -> Accepting `cascade` optional field in the API payload to drop the dependencies, if any -> Accepting `check_metadata_consistency` optional field to bypass (if value set to `false`) the dependency check ### Related Issues <!-- Please make surt title --> <!-- Add the issue number below (e.g. #234) --> Close #1853 ### Solution and Design <!-- How is this iss --> <!-- It's better if we elaborate --> The design/solution follows the `run_sql` API implementation for Postgres backend. ### Steps to test and verify <!-- If this is a fehis is a bug-fix, how do we verify the fix? --> - Create author - article tables and track them - Defined object and array relationships - Try to drop the article table without cascade or cascade set to `false` - The server should raise the relationship dependency exists exception ## Changelog - ✅ `CHANGELOG.md` is updated with user-facing content relevant to this PR. If no changelog is required, then add the `no-changelog-required` label. ## Affected components <!-- Remove non-affected components from the list --> - ✅ Server - ❎ Console - ❎ CLI - ❎ Docs - ❎ Community Content - ❎ Build System - ✅ Tests - ❎ Other (list it) PR-URL: https://github.com/hasura/graphql-engine-mono/pull/2636 GitOrigin-RevId: 0ab152295394056c4ca6f02923142a1658ad25dc
2021-10-22 17:49:15 +03:00
unless (null nonPermDependentObjs) $ reportDependentObjectsExist nonPermDependentObjs
pure roles
where
remoteSchemaDepId = SORemoteSchema rsn
getRole depObj =
case depObj of
SORemoteSchemaPermission _ role -> Just role
_ -> Nothing
nonPermDependentObjPredicate (SORemoteSchemaPermission _ _) = False
nonPermDependentObjPredicate _ = True
runReloadRemoteSchema ::
(QErrM m, CacheRWM m, MetadataM m) =>
RemoteSchemaNameQuery ->
m EncJSON
runReloadRemoteSchema (RemoteSchemaNameQuery name) = do
remoteSchemas <- getAllRemoteSchemas <$> askSchemaCache
unless (name `elem` remoteSchemas)
$ throw400 NotExists
$ "remote schema with name "
<> name
<<> " does not exist"
let invalidations = mempty {ciRemoteSchemas = S.singleton name}
metadata <- getMetadata
withNewInconsistentObjsCheck
$ buildSchemaCacheWithOptions (CatalogUpdate Nothing) invalidations metadata
pure successMsg
runIntrospectRemoteSchema ::
(CacheRM m, QErrM m) => RemoteSchemaNameQuery -> m EncJSON
runIntrospectRemoteSchema (RemoteSchemaNameQuery rsName) = do
sc <- askSchemaCache
RemoteSchemaCtx {..} <-
HashMap.lookup rsName (scRemoteSchemas sc) `onNothing` throw400 NotExists ("remote schema: " <> rsName <<> " not found")
pure $ encJFromLBS _rscRawIntrospectionResult
runUpdateRemoteSchema ::
( QErrM m,
CacheRWM m,
MonadIO m,
harmonize network manager handling ## Description ### I want to speak to the `Manager` Oh boy. This PR is both fairly straightforward and overreaching, so let's break it down. For most network access, we need a [`HTTP.Manager`](https://hackage.haskell.org/package/http-client-0.1.0.0/docs/Network-HTTP-Client-Manager.html). It is created only once, at the top level, when starting the engine, and is then threaded through the application to wherever we need to make a network call. As of main, the way we do this is not standardized: most of the GraphQL execution code passes it "manually" as a function argument throughout the code. We also have a custom monad constraint, `HasHttpManagerM`, that describes a monad's ability to provide a manager. And, finally, several parts of the code store the manager in some kind of argument structure, such as `RunT`'s `RunCtx`. This PR's first goal is to harmonize all of this: we always create the manager at the root, and we already have it when we do our very first `runReaderT`. Wouldn't it make sense for the rest of the code to not manually pass it anywhere, to not store it anywhere, but to always rely on the current monad providing it? This is, in short, what this PR does: it implements a constraint on the base monads, so that they provide the manager, and removes most explicit passing from the code. ### First come, first served One way this PR goes a tiny bit further than "just" doing the aforementioned harmonization is that it starts the process of implementing the "Services oriented architecture" roughly outlined in this [draft document](https://docs.google.com/document/d/1FAigqrST0juU1WcT4HIxJxe1iEBwTuBZodTaeUvsKqQ/edit?usp=sharing). Instead of using the existing `HasHTTPManagerM`, this PR revamps it into the `ProvidesNetwork` service. The idea is, again, that we should make all "external" dependencies of the engine, all things that the core of the engine doesn't care about, a "service". This allows us to define clear APIs for features, to choose different implementations based on which version of the engine we're running, harmonizes our many scattered monadic constraints... Which is why this service is called "Network": we can refine it, moving forward, to be the constraint that defines how all network communication is to operate, instead of relying on disparate classes constraint or hardcoded decisions. A comment in the code clarifies this intent. ### Side-effects? In my Haskell? This PR also unavoidably touches some other aspects of the codebase. One such example: it introduces `Hasura.App.AppContext`, named after `HasuraPro.Context.AppContext`: a name for the reader structure at the base level. It also transforms `Handler` from a type alias to a newtype, as `Handler` is where we actually enforce HTTP limits; but without `Handler` being a distinct type, any code path could simply do a `runExceptT $ runReader` and forget to enforce them. (As a rule of thumb, i am starting to consider any straggling `runReaderT` or `runExceptT` as a code smell: we should not stack / unstack monads haphazardly, and every layer should be an opaque `newtype` with a corresponding run function.) ## Further work In several places, i have left TODOs when i have encountered things that suggest that we should do further unrelated cleanups. I'll write down the follow-up steps, either in the aforementioned document or on slack. But, in short, at a glance, in approximate order, we could: - delete `ExecutionCtx` as it is only a subset of `ServerCtx`, and remove one more `runReaderT` call - delete `ServerConfigCtx` as it is only a subset of `ServerCtx`, and remove it from `RunCtx` - remove `ServerCtx` from `HandlerCtx`, and make it part of `AppContext`, or even make it the `AppContext` altogether (since, at least for the OSS version, `AppContext` is there again only a subset) - remove `CacheBuildParams` and `CacheBuild` altogether, as they're just a distinct stack that is a `ReaderT` on top of `IO` that contains, you guessed it, the same thing as `ServerCtx` - move `RunT` out of `RQL.Types` and rename it, since after the previous cleanups **it only contains `UserInfo`**; it could be bundled with the authentication service, made a small implementation detail in `Hasura.Server.Auth` - rename `PGMetadaStorageT` to something a bit more accurate, such as `App`, and enforce its IO base This would significantly simply our complex stack. From there, or in parallel, we can start moving existing dependencies as Services. For the purpose of supporting read replicas entitlement, we could move `MonadResolveSource` to a `SourceResolver` service, as attempted in #7653, and transform `UserAuthenticationM` into a `Authentication` service. PR-URL: https://github.com/hasura/graphql-engine-mono/pull/7736 GitOrigin-RevId: 68cce710eb9e7d752bda1ba0c49541d24df8209f
2023-02-22 18:53:52 +03:00
ProvidesNetwork m,
MetadataM m,
Tracing.MonadTrace m
) =>
Env.Environment ->
AddRemoteSchemaQuery ->
m EncJSON
runUpdateRemoteSchema env (AddRemoteSchemaQuery name defn comment) = do
remoteSchemaNames <- getAllRemoteSchemas <$> askSchemaCache
remoteSchemaMap <- _metaRemoteSchemas <$> getMetadata
let metadataRMSchema = InsOrdHashMap.lookup name remoteSchemaMap
metadataRMSchemaPerms = maybe mempty _rsmPermissions metadataRMSchema
-- `metadataRMSchemaURL` and `metadataRMSchemaURLFromEnv` represent
-- details that were stored within the metadata
metadataRMSchemaURL = (_rsdUrl . _rsmDefinition) =<< metadataRMSchema
metadataRMSchemaURLFromEnv = (_rsdUrlFromEnv . _rsmDefinition) =<< metadataRMSchema
-- `currentRMSchemaURL` and `currentRMSchemaURLFromEnv` represent
-- the details that were provided in the request
currentRMSchemaURL = _rsdUrl defn
currentRMSchemaURLFromEnv = _rsdUrlFromEnv defn
unless (name `elem` remoteSchemaNames)
$ throw400 NotExists
$ "remote schema with name "
<> name
<<> " doesn't exist"
rsi <- validateRemoteSchemaDef env defn
-- we only proceed to fetch the remote schema if the url has been updated
unless
( (isJust metadataRMSchemaURL && isJust currentRMSchemaURL && metadataRMSchemaURL == currentRMSchemaURL)
|| (isJust metadataRMSchemaURLFromEnv && isJust currentRMSchemaURLFromEnv && metadataRMSchemaURLFromEnv == currentRMSchemaURLFromEnv)
)
harmonize network manager handling ## Description ### I want to speak to the `Manager` Oh boy. This PR is both fairly straightforward and overreaching, so let's break it down. For most network access, we need a [`HTTP.Manager`](https://hackage.haskell.org/package/http-client-0.1.0.0/docs/Network-HTTP-Client-Manager.html). It is created only once, at the top level, when starting the engine, and is then threaded through the application to wherever we need to make a network call. As of main, the way we do this is not standardized: most of the GraphQL execution code passes it "manually" as a function argument throughout the code. We also have a custom monad constraint, `HasHttpManagerM`, that describes a monad's ability to provide a manager. And, finally, several parts of the code store the manager in some kind of argument structure, such as `RunT`'s `RunCtx`. This PR's first goal is to harmonize all of this: we always create the manager at the root, and we already have it when we do our very first `runReaderT`. Wouldn't it make sense for the rest of the code to not manually pass it anywhere, to not store it anywhere, but to always rely on the current monad providing it? This is, in short, what this PR does: it implements a constraint on the base monads, so that they provide the manager, and removes most explicit passing from the code. ### First come, first served One way this PR goes a tiny bit further than "just" doing the aforementioned harmonization is that it starts the process of implementing the "Services oriented architecture" roughly outlined in this [draft document](https://docs.google.com/document/d/1FAigqrST0juU1WcT4HIxJxe1iEBwTuBZodTaeUvsKqQ/edit?usp=sharing). Instead of using the existing `HasHTTPManagerM`, this PR revamps it into the `ProvidesNetwork` service. The idea is, again, that we should make all "external" dependencies of the engine, all things that the core of the engine doesn't care about, a "service". This allows us to define clear APIs for features, to choose different implementations based on which version of the engine we're running, harmonizes our many scattered monadic constraints... Which is why this service is called "Network": we can refine it, moving forward, to be the constraint that defines how all network communication is to operate, instead of relying on disparate classes constraint or hardcoded decisions. A comment in the code clarifies this intent. ### Side-effects? In my Haskell? This PR also unavoidably touches some other aspects of the codebase. One such example: it introduces `Hasura.App.AppContext`, named after `HasuraPro.Context.AppContext`: a name for the reader structure at the base level. It also transforms `Handler` from a type alias to a newtype, as `Handler` is where we actually enforce HTTP limits; but without `Handler` being a distinct type, any code path could simply do a `runExceptT $ runReader` and forget to enforce them. (As a rule of thumb, i am starting to consider any straggling `runReaderT` or `runExceptT` as a code smell: we should not stack / unstack monads haphazardly, and every layer should be an opaque `newtype` with a corresponding run function.) ## Further work In several places, i have left TODOs when i have encountered things that suggest that we should do further unrelated cleanups. I'll write down the follow-up steps, either in the aforementioned document or on slack. But, in short, at a glance, in approximate order, we could: - delete `ExecutionCtx` as it is only a subset of `ServerCtx`, and remove one more `runReaderT` call - delete `ServerConfigCtx` as it is only a subset of `ServerCtx`, and remove it from `RunCtx` - remove `ServerCtx` from `HandlerCtx`, and make it part of `AppContext`, or even make it the `AppContext` altogether (since, at least for the OSS version, `AppContext` is there again only a subset) - remove `CacheBuildParams` and `CacheBuild` altogether, as they're just a distinct stack that is a `ReaderT` on top of `IO` that contains, you guessed it, the same thing as `ServerCtx` - move `RunT` out of `RQL.Types` and rename it, since after the previous cleanups **it only contains `UserInfo`**; it could be bundled with the authentication service, made a small implementation detail in `Hasura.Server.Auth` - rename `PGMetadaStorageT` to something a bit more accurate, such as `App`, and enforce its IO base This would significantly simply our complex stack. From there, or in parallel, we can start moving existing dependencies as Services. For the purpose of supporting read replicas entitlement, we could move `MonadResolveSource` to a `SourceResolver` service, as attempted in #7653, and transform `UserAuthenticationM` into a `Authentication` service. PR-URL: https://github.com/hasura/graphql-engine-mono/pull/7736 GitOrigin-RevId: 68cce710eb9e7d752bda1ba0c49541d24df8209f
2023-02-22 18:53:52 +03:00
$ void
$ fetchRemoteSchema env rsi
-- This will throw an error if the new schema fetched in incompatible
-- with the existing permissions and relations
withNewInconsistentObjsCheck
$ buildSchemaCacheFor (MORemoteSchema name)
$ MetadataModifier
$ metaRemoteSchemas
%~ InsOrdHashMap.insert name (remoteSchemaMeta metadataRMSchemaPerms)
pure successMsg
where
remoteSchemaMeta perms = RemoteSchemaMetadata name defn comment perms mempty