Adding custom DataSource as a dependency to an auto-generated resolver function.

[LukeHalby]

Which Category is your question related to?
API

Amplify CLI Version
10.2.3

Details

I have extended an auto-generated pipeline resolver by added 2 postUpdate functions to it (as shown below).

The MutationcreateChatroompostUpdate1Function function makes a BatchPutItem request to a DynamoDB table. I had originally created that DataSource on the web console but now I need it to be defined locally and have it update upon amplify push.

I originally added the following code to my CustomResource.json file, but the auto-generated stack failed update because it needs this as a dependency.

    "BatchRequestDataSource": {
      "Type" : "AWS::AppSync::DataSource",
      "Properties" : {
          "ApiId" : { "Ref": "AppSyncApiId" },
          "Description" : "A non-existent table to be used as a DataSource for batch requests in resolvers",
          "DynamoDBConfig" : {
            "AwsRegion": "ap-southeast-2",
            "TableName": "empty"
          },
          "Name" : "BATCH_DS",
          "ServiceRoleArn" : "MyBatchReadWriteArn",
          "Type" : "AMAZON_DYNAMODB"
        }
    }

I then tried to create the resource in overrides.ts with aws-cdk and use it in the .addDependsOn() method, but that failed on push with Error: Skipping override due to VMError: Cannot find module 'fs'.

    const batch = new CfnDataSource(this, 'BatchRequestDataSource', {
        apiId: resources.api.GraphQLAPI.attrApiId,
        description: "A non-existent table to be used as a DataSource for batch requests in resolvers",
        dynamoDbConfig: {
            tableName: "empty",
            awsRegion: "ap-southeast-2"
        },
        name: BATCH_DS,
        serviceRoleArn: "MyBatchReadWriteArn",
        type: "AMAZON_DYNAMODB"
    })

Scoured this repo for related issues but found nothing, any help is welcome and much appreciated!

[ykethan]

Hey @LukeHalby, thank you for reaching out. The issue is similar to #109. In a custom CDK resource using amplify add custom fs ops are permitted and we should be able to add a DataSource to a resolver: https://docs.aws.amazon.com/cdk/api/v1/docs/@aws-cdk_aws-appsync.Resolver.html#class-resolver-construct-span-classapi-icon-api-icon-experimental-titlethis-api-element-is-experimental-it-may-change-without-noticespan.
Additionally, please refer to the RFC: #430 (comment) to enable Datasource for pipeline resolvers