Instead of deploying individual configuration files, you would generate `/etc/nixos/configuration.nix` + some modules maybe followed by a `nixos-rebuild switch`.
There is not special support required in Chef/Ansible to support this feature. Both Chef and Ansible are available in nixpkgs.
Some time ago, I asked how to integrate NixOS in an existing infrastructure managed by Chef/Ansible.
I was told I was wrong to even think about that and that Nix is a better system.
Well, wrong. If you have a few thousands servers with a system, you cannot ask to migrate all to a new system without some integration with the old one first.