The TL;DR is ergomake/layerform is a GPL v3 licensed package/service that lets one create instances of infrastructure sets through composition of Terraform. It presents itself with Kubernetes examples but its readme has goal of doing any type of infrastructure.

I sort of fail to see why one just can't write reusable Terraform modules already to accomplish the same. If you don't want someone modifying a base layer, than that is achieved with OWNERS files for source control, and role-based access control for the identifies/credentials, for the underlying infra services, used by the Terraform plan.

But for those familiar with Kubernetes already, it is essentially Kustomize [1] for Terraform. Although if you are using Kubernetes already, the alternative is to write an Operator yourself to create a self-serve environment provisioner. That way the operators have their own service accounts, roles, and secrets. And quotas/rate limits can be achieved through admission control. Existing way for reporting to know that things failed to deploy, and so on...

[1] https://kustomize.io