nixos kind of does that except better. Usually just set services.foo.enabled to true along with any other config you want. It's also super easy to wrap services

nixos kind of does that except better. Usually just set services.foo.enabled to true along with any other config you want. It's also super easy to wrap services in a container if you want, and doing so is kept conceptually separate from dependency management. If you want to make your own systemd service, then referencing a package in `ExecStart` or whatever will make it automatically get pulled in as a dependency.