GeezerVison

Motivation

When redeploying CloudFormation stacks that contain Fn::FindInMap with nested intrinsic functions (like {"Ref": "AWS::Partition"}), LocalStack raised a misleading error:

InternalFailure: The API action 'CreateChangeSet' for service 'cloudformation' is either not available in your current license plan or has not yet been emulated by LocalStack.

This particularly affected CDK-generated templates that use CloudFront distributions with Route53 ARecord alias targets, where the hosted zone ID is determined using:

{
  "Fn::FindInMap": [
    "AWSCloudFrontPartitionHostedZoneIdMap",
    {"Ref": "AWS::Partition"},
    "zoneId"
  ]
}

Changes

Modified _resolve_intrinsic_function_fn_find_in_map in the changeset model to handle non-terminal values (nested intrinsic functions) by calling parent_change_type_of() instead of raising NotImplementedError.

Tests

Added 3 AWS-validated tests to test_change_set_mappings.py to validate the exact bug scenario and that change detection still works correctly.

Related

Fixes #13491
Closes UNC-165