SLS Offline DynamoDB Streams: Several issues referencing DynamoDB table streams

[cwienands1]

I am using SLS Offline DynamoDB Streams (SODS) to develop and test a Serverless + NodeJS application that uses DynamoDB streams to trigger additional Lambda functions. I have struggled with specifying the ARN of the DynamoDB stream correctly and during that course found several issues around this.

Issue 1: At the very bottom of the SODS NPM page an example describes a variant using a tableName key. This does work and from all I can tell is also not supported by the getTableName function.

Issue 2: Line 186 of index.js is missing an additional null check for arn: if (tableEvent.arn && tableEvent.arn['Fn::GetAtt']) {

Issue 3: I did not test this but from all I can tell, there are two more ways to specify a DynamoDB table stream in Serverless that are not supported by SODS:

      - stream:
          type: dynamodb
          arn:
            Fn::ImportValue: MyExportedDynamoDbStreamArnId
      - stream:
          type: dynamodb
          arn:
            Ref: MyDynamoDbTableStreamArn

It could be that those two ways are not feasible for local deployments (again, I didn't test them) but I figured I'll point it out anyway.

Time permitting I'll put together a pull request for no. 2. Not sure what you would want to do about no. 1 and 3.

[cmygray]

Got the same issue and solved by adding streamName property under stream event. But I'm not sure it is a good or bad approach.

Or, it can be solved by passing arn string correctly.

Or, use CloudFormation Fn::GetAtt: (Target table should be contained to CloudFormation Resource)

[AdrieanKhisbe]

Hello and sorry for late answer :/

As correctly point out @cmygray Fn::GetAtt would do the job. CloudformationLike resolving is very limited and so farr there is no support for local Fn::ImportValue and Ref

getTableName does not exist anymore, tableName might have been lost at some point. Will need to check

[AdrieanKhisbe]

getTableName does not exist anymore, tableName might have been lost at some point. Will need to check

after checking repo when message was introduced [9805f89], that might be a problem of wording: To me arn could be deduce from tableName if your add the key tableName in your function's configuration. Useful if your use dynalite and regularly recreate a new DynamoDBStreams. implicitely talks about the tableName in the events in the function, not the function configuration itself