stepfunctions task - support dynamodb

[nija-at]

https://docs.aws.amazon.com/step-functions/latest/dg/connect-ddb.html

---

This is a 🚀 Feature Request

[ayush987goyal]

Hi @nija-at ,

To implement this, I was thinking of having individual classes for all 4 APIs (GetItem, PutItem, DeleteItem and UpdateItem) that implement IStepFunctionsTask and one public class called CallDynamoDB which has static methods for each of these APIs that instantiates and returns a task object for these.

So basically,

class GetItemTask implements sfn.IStepFunctionsTask {
	...
}

class PutItemTask implements sfn.IStepFunctionsTask {
	...
}

class DeleteItemTask implements sfn.IStepFunctionsTask {
	...
}

class UpdateItemTask implements sfn.IStepFunctionsTask {
	...
}

export class CallDynamoDB {
	static getItemTask(props: GetItemTaskProps) {
		return new GetItemTask(props);
	}

	.
	.
	.

	static updateItemTask(props: UpdateItemTaskProps) {
		return new UpdateItemTask(props);
	}
}

How does that sound?

[nija-at]

This sounds like a good start. I would prefix the classes with the service name and drop the Task suffix, so DynamoGetItem, DynamoPutItem, etc.

[ayush987goyal]

@nija-at Hi, I am having trouble installing @aws-cdk/aws-dynamodb as a dependency of @aws-cdk/aws-stepfunctions-tasks. This is what I am doing in aws-cdk/packages/@aws-cdk/aws-stepfunctions-tasks sub-directory:

1. yarn add @aws-cdk/aws-dynamodb@0.0.0
2. ../../../scripts/buildup

I am getting following error

cdk-build Error:
Error: Unable to locate module: @aws-cdk/aws-dynamodb

I am not sure what I am doing wrong and what I should do instead.

[ayush987goyal]

I ran a yarn build in the root and I am getting the following error

lerna ERR! ECYCLE Dependency cycles detected, you should fix these!
lerna ERR! ECYCLE @aws-cdk/aws-dynamodb -> @aws-cdk/custom-resources -> @aws-cdk/aws-stepfunctions-tasks -> @aws-cdk/aws-dynamodb

I think there is a cycle in the dependencies. The custom-resources package requires aws-stepfunctions-tasks. How do we handle this scenario?