Subscriptions on AWS API Gateway Websockets with Serverless and Apollo (GraphQL)

[IonelLupu]

I have a project where I want to implement Apollo GrapQL Subscriptions through Websockets (of course 😄 ) using the Serverless framework on AWS. I read some issues about this here but I didn't find a solution or example about this type of setup 😢 .

I did a few things that got me closer to the setup but I still have some blockers. I did the connection part and now the client is sending this message through Websockets:

{"type":"connection_init","payload":{"Authorization":"Bearer my-token"}}

But when working with Serveless framework on AWS we have to send (as per docs) a message that contains the action property in order to make the entire process work and send the client message to the lambda function and handle the GraphQL query.

I am thinking I just a few things:

• a way to send a Websocket message with the action property because this is what "AWS API Gateway Websockets" requires. Eg: {"action":"message","message":"here I can have my graphql subscription query"}. Having this action property, AWS can trigger the lambda function that will handle the message.
• after I get the message, I need the "message interpreter" (if that's a thing) from graphql-ws to process it, give it to Apollo where it will return me the response. This response needs to be processed into a graphql-ws response so the client understand it (I assume).

But I am stuck here. Is there an example project with a graphql-ws server that handles the messages from the graphql-ws client without express, or fastify or ws, just from a raw messaage?

[enisdenjo]

graphql-ws's server implementation is actually just a coercing API that can be plugged into any WebSocket server library by using makeServer. Check out the built-ins for ws, uWebSockets and fastify-websocket to get started.

Furthermore, this library is a reference implementation of the GraphQL over WebSocket protocol and is therefore required to have the messages format comply with the protocol; so, no, graphql-ws will not accept messages differing from the protocol.

However, I am aware of two libraries of intereset that aim to integrate the GraphQL over WebSocket protocol on AWS:

• subscriptionless
• graphql-lambda-subscriptions

[IonelLupu]

I ended up using graphql-lambda-subscriptions but I still have issues setting it up getting weird errors like Cannot read property 'definitions' of undefined. I will have to post an issue on their side.

Thank you very much for the reponse!

[IonelLupu]

btw. I found out why I got that error about definitions: the library was using the graphQL 16 and my app was using graphQL 15.

[samhatoum]

@IonelLupu did you use graphql-lambda-subscriptions with or without Apollo server in the end? Thanks in advance 🙏

[IonelLupu]

@samhatoum oh. This was so long ago. I don't really remember

[samhatoum]

I guess I'll just have to try!