Has anyone explored CD tooling with Nix? And I don't mean the deployment of NixOS machines themselves (NixOps, deploy-rs, etc), I mean actually using Nix for deployment tooling and orchestrating deployments using the Nix language.

I am yet to find any posts about this or any tools, but have had great success with a small hand rolled tool that essentially lets me decoratively describe cloud resources, parts of my application, deployment "end state", and run the tools required to materialise that (Terraform, nixos-rebuild, etc) similar to GitHub Actions. Hydra is distributed CI for nix-build but does not handle CD or is designed to handle jobs with side effects AFAIK.

NixOS is great, but for me this is even more valuable, as I now have an introspect-able view of my entire deployed real estate, and can essentially `nix run ...` to deploy any part of my application in its entirety along with any dependencies.