How to receive / process DynamoDB Triggers?

[joeuelk]

Does anyone know how to receive a DynamoDB trigger?

The example below works fine with the APIGateway but I can't get it to process DDB Triggers.

I've verified data is being sent to this Lambda when I write to a table that has a stream setup but I am getting an error saying it can't decode the data because the resource coding key is missing.

I've tried changing the event and the In values to various things but nothing is working.

Thanks

struct LamdaHandler: EventLoopLambdaHandler {
    
    typealias In = APIGateway.Request
    typealias Out = APIGateway.Response
    
    func handle(context: Lambda.Context, event: APIGateway.Request) -> EventLoopFuture<APIGateway.Response> {
        guard let handler = Handler.current else {
            return context.eventLoop.makeSucceededFuture(APIGateway.Response(with: APIError.requestError, statusCode: .badRequest))
        }
    }

}

[adam-fowler]

This question should probably be asked in the swift-aws-lambda-runtime repo, but I can see if I can help. First it looks like you are using an old version of the lambda runtime. It hasn't had a release in a while, but has had quite a few updates like moving all the event types to swift-aws-lambda-events and async/await support.

DynamoDB triggered lambdas should use DynamoDBEvent from the swift-aws-lambda-events repo as their In type. eg

struct LamdaHandler: EventLoopLambdaHandler {
    typealias In = DynamoDBEvent
    typealias Out = Void
    
    func handle(context: Lambda.Context, event: APIGateway.Request) -> EventLoopFuture<APIGateway.Response> {
        guard let handler = Handler.current else {
            return context.eventLoop.makeSucceededVoidFuture())
        }
    }
}

If that doesn't work then there is most likely an error in the DynamoDBEvent type and an issue should be raised in the events repo.

[joeuelk]

I think I'm getting confused about the difference between soto and the swift-aws-lambda-runtime. Is there overlap? Does one replace the other? Is there an equivalent EventLoopLambdaHandler within Soto?

Thank you!

[0xTim]

Soto is an SDK for calling AWS services via their API. The AWS Lambda runtime allows you to run Swift code in lambdas. There's no overlap between the two