This PR reverts the following two commits:
1. https://github.com/hasura/graphql-engine-mono/pull/8287
2. https://github.com/hasura/graphql-engine-mono/pull/8467
We are undoing a migration that was done on `hdb_catalog.event_log` table which was done in d4ae6a517da63f2f43567dc16fda135b3cd1d7e6 . And as such, users who were using event triggers on that version will come across the error:
```json
{"detail":{"info":{"code":"not-supported","error":"Expected source catalog version <= 3, but the current version is 4","path":"$"},"kind":"catalog_migrate"},"level":"error","timestamp":"2023-03-28T10:17:24.289+0530","type":"startup"}
{"code":"not-supported","error":"Expected source catalog version <= 3, but the current version is 4","path":"$"}
```
To fix these errors please run the following SQL on the source where event triggers were created on:
```
UPDATE hdb_catalog.hdb_source_catalog_version SET version = 3, upgraded_on= NOW();
ALTER table hdb_catalog.event_log ALTER COLUMN created_at SET DEFAULT NOW();
ALTER table hdb_catalog.event_invocation_logs ALTER COLUMN created_at SET DEFAULT NOW();
```
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/8534
GitOrigin-RevId: b6bbcce0163c8beed80619d3cea056e643b8c180
### Description
This PR is one more step towards #8344: it splits `initializeContext` into two parts: the first one builds the `AppEnv`, and the second builds the `AppContext` and its corresponding `AppStateRef`. Splitting it allows us to run the first schema cache build _in the app monad_, which was one of the steps required to remove `CacheBuild`, and ultimately to achieve #8344, which in turn is a blocker for several projects.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/8445
GitOrigin-RevId: 0ef9eeec0c941b915da505cc9b1c60f36b108a56
### Description
This small PR is on top of #8440. It continues the cleanup of `Hasura/App` by grouping together all instances on the app monad, renaming the app monad, and removing its `m` parameter.
See [this commit](cb6ecba3d4) to see the diff in isolation.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/8441
GitOrigin-RevId: 7abb6524a160bcb4f75e729e726ce2af69643998
### Description
As part of another project (the continuation of #8421), i have started a cleanup of `Hasura.App`, focusing on deleting old code and grouping together things that belong together. This quickly grew into a refactor of `GlobalCtx`, now renamed into `BasicConnectionInfo`. This small refactor adds comments, and aims at making clear what the purpose of those types and functions is.
Furthermore, it also changes the way the default postgres connection info is created, by making that part of the process of creating the `BasicConnectionInfo`, to deduplicate similar effort across different files.
This is expected to be a no-op.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/8440
GitOrigin-RevId: 412c5b1905f629beb9c6cd262b9798cb31c93bdb
### Description
This PR continues some of the work done in #8392, and makes use of `HasAppEnv` to reduce the amount of explicit env passing in init functions, including removing it from the setup hook.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/8408
GitOrigin-RevId: 4d6c906f78fbcc303571f9aac16d163d68b77e41
This PR is on top of #7789.
### Description
This PR entirely rewrites the API of the Tracing library, to make `interpTraceT` a thing of the past. Before this change, we ran traces by sticking a `TraceT` on top of whatever we were doing. This had several major drawbacks:
- we were carrying a bunch of `TraceT` across the codebase, and the entire codebase had to know about it
- we needed to carry a second class constraint around (`HasReporterM`) to be able to run all of those traces
- we kept having to do stack rewriting with `interpTraceT`, which went from inconvenient to horrible
- we had to declare several behavioral instances on `TraceT m`
This PR rewrite all of `Tracing` using a more conventional model: there is ONE `TraceT` at the bottom of the stack, and there is an associated class constraint `MonadTrace`: any part of the code that happens to satisfy `MonadTrace` is able to create new traces. We NEVER have to do stack rewriting, `interpTraceT` is gone, and `TraceT` and `Reporter` become implementation details that 99% of the code is blissfully unaware of: code that needs to do tracing only needs to declare that the monad in which it operates implements `MonadTrace`.
In doing so, this PR revealed **several bugs in the codebase**: places where we were expecting to trace something, but due to the default instance of `HasReporterM IO` we would actually not do anything. This PR also splits the code of `Tracing` in more byte-sized modules, with the goal of potentially moving to `server/lib` down the line.
### Remaining work
This PR is a draft; what's left to do is:
- [x] make Pro compile; i haven't updated `HasuraPro/Main` yet
- [x] document Tracing by writing a note that explains how to use the library, and the meaning of "reporter", "trace" and "span", as well as the pitfalls
- [x] discuss some of the trade-offs in the implementation, which is why i'm opening this PR already despite it not fully building yet
- [x] it depends on #7789 being merged first
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/7791
GitOrigin-RevId: cadd32d039134c93ddbf364599a2f4dd988adea8
## 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
