Subscriptions?

[mjfrnd]

Hello! I appreciate this project very much. Thank you all for the work you've put in.

I'm wondering if there is any information about implementing GraphQL subscriptions with graphql-mesh as a gateway. I have an Apollo gateway currently, and subscriptions have been on the Apollo road map for a while with no updates. I read that subscriptions are either supported or are going to be supported in graphql-mesh in the medium post here: https://medium.com/the-guild/graphql-mesh-query-anything-run-anywhere-433c173863b5

Are they already supported?

Thanks again!

[ardatan]

It depends on what source are you using? If gRPC, yes we do. If OData, no because OData doesn't have anything realtime. If Swagger, not for now because it is a bit tricky. If Thrift, yes. If GraphQL, yes.

[mjfrnd]

Thanks! That's great. I'm using federated graphql sources that use apollo-server. I have not had any luck finding examples of this setup (with subscriptions), and I've looked around for a while. I know it's early days but are you aware of any docs around this?

Thank you again!

[Urigo]

@mjf2152 would you be interested at starting setting up a simple example, it doesn't have to be fully functional.
Then it would be easier to jump in and help you get it working.
After that you could submit it as a PR?

[mjfrnd]

@Urigo, thank you for the offer to help -- right now I don't have time to work on an example (I am living without subscriptions for now) but if I do in the next few weeks I will let you know.

[Urigo]

Also related to that is the new subscriptions support openapi-to-graphql just added

[alfaproject]

On this topic. We have a serverless architecture and the websocket connection is managed by AWS API Gateway, so behind that we only have lambdas.

With that said, our current solution is a custom built one where we forward the 'subscribe' query to the upstream lambda with graphql-tools stitching in which the first time, it just registers the connection in DynamoDB and we return a dummy async iterator, etc. We basically emulated the subscriptions protocol to do this.

The whole GraphQL ecosystem seems to expect an always running websocket server for subscriptions, so I was wondering what's your take in serverless solutions and if GraphQL mesh could support something like this natively.

Our solution is VERY similar to this one if you are wondering how it all works: https://github.com/michalkvasnicak/aws-lambda-graphql#readme

[ardatan]

GraphQL Mesh can initiate an HTTP Server for you or Mesh can give you a local GraphQLSchema instance that you can execute in your existing code without initiating an extra HTTP Server or Mesh can generate a completely type-safe SDK for you to be used in your existing project without dealing with GraphQL. So in last 2 scenerios, there is no websocker server used because everything is programmatic.

[alfaproject]

I know there isn't. We don't have one because it's lambda. It's not a long running server. We have to do a fake 'subscribe' to an empty async iterator and manually forward the subscribe query to the stitched lambda.

I've researched more your product and doesn't look like we can replace our manually built gateway. It basically suffers from the same thing as Apollo Federation. The whole ecosystem support for stitched subscriptions with custom protocols doesn't look mature yet. ):

[Urigo]

@alfaproject sorry for the late response.
I would love to follow up on that and possibly make it happen.
What is the part that you wish would be customizable in GraphQL Mesh when running as a gateway?
What would be the best way to move this forward?
Maybe some kind of an RFC?
Maybe an example project repo to work on together?

I looked a bit about how AppSync is managing subscriptions and it's also very interesting.

[alfaproject]

We don't use AppSync for different reasons but I'll see if I can come up with a small project that looks like ours.

Can't promise when yet because I'm going on vacation tomorrow until next week, but I think I might be able before or on the next weekend.

[Urigo]

thank you for helping us with that!

[ardatan]

Now it is possible to consume webhooks as GraphQL Subscriptions;
https://graphql-mesh.com/docs/recipes/subscriptions-webhooks

[dpnova]

Hello - I've been reading the code and it looks like mesh is hard coded to use the vanilla pubsub provided by graphql-subscriptions

This is a problem because it means mesh can only ever run as a single node.

I'd love to be able to implement a pubsub for eventbridge and wire it in instead, that would require forking mesh though.

Do you have a pattern for allowing different implementations of standard interfaces? Would it apply here?

[dpnova]

Actually I just saw resolvePubSub - that seems like "the way" right?

[ardatan]

Yes, Mesh allows you to use other pub sub implementations :)
https://github.com/apollographql/graphql-subscriptions#pubsub-implementations.

[dpnova]

Yep, I saw that buut it wasn't clear to me which part of the settings I would define the implementation to use.

I'm happy to pr a doc improvement once I understand it

[ardatan]

Sorry for the missing documentation :) You're right.
I'll add it soon :)