(CDK Migrate CLI): CDK Migrate command does not filter out type Custom::* resource with flag --filter resource-type-prefix

[jiem-ying]

Describe the bug

I have an existing stack with one CR and one Lambda function. Following commands all face the same error:

cdk migrate --language typescript --from-stack --stack-name 'CustomResourceCrossRegionExport' --filter resource-type-prefix="AWS::Lambda::" 
cdk migrate --language typescript --from-stack --stack-name 'CustomResourceCrossRegionExport' --filter resource-type-prefix="AWS::DynamoDB::"

Expected Behavior

The filter should filter the Custom:: resource out and only import the Lambda function.

Current Behavior

Error:

Migrate failed for `CustomResourceCrossRegionExport`: stack generation failed due to error 'TransmuteError: invalid resource type name: Custom::GetExportsValueFromRegion'

Reproduction Steps

Deploy a CFN stack with one CR one Lambda function Function. Use the command described above

Possible Solution

No response

Additional Information/Context

No response

CDK CLI Version

1.128

Framework Version

No response

Node.js Version

20

OS

MacOS

Language

TypeScript

Language Version

No response

Other information

No response

[tim-finnigan]

Hi @jiem-ying thanks for reaching out. Can you share your stack code snippet for reproducing the issue? Also here is the cdk migrate documentation for reference: https://docs.aws.amazon.com/cdk/v2/guide/migrate.html. As noted there, "The CDK Migrate feature is in preview release for AWS CDK and is subject to change."

[jiem-ying]

AWSTemplateFormatVersion: '2010-09-09'
Parameters:
  ExportsName:
    Description: The exports name from the export CFN stack
    Type: String
    Default: SampleNetworkCrossStack-VPCID
  ExportRegion:
    Description: Target Region
    Type: String
    Default: ap-southeast-2
  LambdaExecutionRole:
    Description: a sufficient role to allow Lambda execute actions on your CloudFormation resource.
    Type: String
    Default: arn:aws:iam::126672810070:role/lambda-ex

Resources:
  LambdaFunction:
    Type: AWS::Lambda::Function
    Properties:
      FunctionName: FunctionToGetOtherRegionCFNExportTest
      Handler: index.lambda_handler
      Role: !Ref LambdaExecutionRole
      Code:
        ZipFile: |
          import boto3
          import cfnresponse
          def lambda_handler(event, context):
              print ('REQUEST BODY:n' + str(event))
              #two properties values passed to variable "parameter_name" and "parameter_region"
              parameter_name = (event['ResourceProperties']['Parameter'])
              parameter_region = (event['ResourceProperties']['Region'])
              physicalResourceId = "hardcodephysicalidforbestpractice"
              print (parameter_name)
              try:
                  if event['RequestType'] == 'Delete':
                      print ("delete")
                      responseData = {"Message": "Delete success"}
                      cfnresponse.send(event, context, cfnresponse.SUCCESS, responseData,physicalResourceId)
                  elif event['RequestType'] == 'Create':
                      print ("create")
                      #Boto3 module create a session based on the "parameter_region" for 'cloudformation' service:
                      client = boto3.Session(region_name= parameter_region).client('cloudformation')

                      #Then the list_exports() function[2] is called and all CFN exports of the target region is returned under the key ['Exports']:
                      exports = client.list_exports()['Exports']
                      
                      #Then a for loop is claimed to find the targeted export name's value
                      for export in exports:
                        if export['Name'] == parameter_name:
                          exportsValue = export['Value']
                      print (exportsValue)
                      #The export value finally put into the responseData and the cfnresponse module[3] 
                      #return the export value to Custom Resource "ExportFetchCustomResource" under attribute 'ExportsValue
                      responseData = {'ExportsValue': exportsValue}    
                      cfnresponse.send(event, context, cfnresponse.SUCCESS, responseData, physicalResourceId)
                  elif event['RequestType'] == 'Update':
                      print ("update")
                      client = boto3.Session(region_name=parameter_region).client('cloudformation')
                      exports = client.list_exports()['Exports']
                      for export in exports:
                        if export['Name'] == parameter_name:
                          exportsValue = export['Value']
                      print (exportsValue)
                      responseData = {'ExportsValue': exportsValue}
                      cfnresponse.send(event, context, cfnresponse.SUCCESS, responseData,physicalResourceId)
                  else:
                      responseData = {"Message": "Unexpected event received from CloudFormation"}
                      cfnresponse.send(event, context, cfnresponse.FAILED, responseData,physicalResourceId)

              except Exception as e:
                  print (e)
                  responseData = {'Failure': "operation failed, please check if the region and export name are correct"}
                  cfnresponse.send(event, context, cfnresponse.FAILED, responseData)   
      Runtime: python3.9
      Timeout: 60
      
  ExportFetchCustomResource: 
    Type: Custom::GetExportsValueFromRegion
    Properties:
      #ServiceToken: arn:aws:lambda:us-west-2:126672810070:function:FunctionToGetOtherRegionCFNExportTest
      ServiceToken: !GetAtt LambdaFunction.Arn
      Parameter: !Ref ExportsName
      Region: !Ref ExportRegion
      TriggerUpdate: "L2"

Outputs:
  RetrievedCrossRegionValue:
    Description: Cross Region value from custom resource ExportFetchCustomResource
    Value: !GetAtt ExportFetchCustomResource.ExportsValue

Or can just create a separate random Lambda function with a CR -> service token to an existing lambda function. Same issue

[TheRealAmazonKendra]

Filters only work on resource scans, not on --from-stack. We should improve the documentation on this and add error handling so that if someone provides the wrong set of flags on the wrong source type, we let them know immediately.

Thanks for reporting this!