Stratosphere: AWS CloudFormation in Haskell

AWS CloudFormation is a system that provisions and updates Amazon Web Services (AWS) resources based on declarative templates. Common criticisms of CloudFormation include the use of JSON as the template language and limited error-checking, often only available in the form of run-time errors and stack rollbacks. By wrapping templates in Haskell, we are able to easily construct them and help ensure correctness.

The goals of stratosphere are to:

• Build a Haskell EDSL to specify CloudFormation templates. Since it is embedded in Haskell, it is type-checked and generally much easier to work with than raw JSON.
• Have a simple checking/linting system outside of the types that can find common errors in templates.
• Be able to also read valid CloudFormation JSON templates so they can be type-checked. This also gives us free integration tests by using the huge amount of example templates available in the AWS