Aws cloudformation introduces cross-account and cross-region stack output referencing

AWS CloudFormation has introduced a new intrinsic function, Fn::GetStackOutput, which allows users to reference stack outputs across different AWS accounts and Regions directly in CloudFormation templates and CDK applications. This enhancement streamlines the process of provisioning and managing workloads that span multiple accounts and Regions, while also preventing deployment issues related to cross-stack dependencies in CDK applications.

In environments where multiple AWS accounts are utilized, teams often face the challenge of sharing infrastructure information, such as VPC IDs or database endpoints, across account boundaries. Previously, this process involved several steps, including manually copying values between templates or coordinating parameter updates among teams. The introduction of Fn::GetStackOutput simplifies this by allowing users to specify the target stack name, output key, an IAM role ARN for cross-account access, and optionally a Region. CloudFormation then assumes the specified role to retrieve and resolve the output value during template processing, minimizing manual coordination and reducing the risk of configuration errors.

In CDK applications, the new function automatically handles cross-account and cross-Region references, eliminating the need for custom resources and SSM parameters that were previously necessary. Additionally, developers can directly call Fn.getStackOutput to create loose references between stacks, facilitating easier refactoring of stack structures.

To begin using this feature, users should incorporate the Fn::GetStackOutput function into their CloudFormation templates and ensure the correct IAM permissions are configured for cross-account access. In CDK, the function is used automatically for cross-account and cross-Region references. For more detailed information, users can refer to the AWS CloudFormation User Guide or the CDK developer guide.

This new capability is available in all AWS Regions that support CloudFormation. Users can consult the AWS Region table to confirm service availability.