mgit-at / nix-unify

Use NixOS parts in your host operating-system, for a step-by-step migration

nix-unify

Use NixOS parts in your host operating-system, for a step-by-step migration.

This repository contains multiple parts, each usable on their own:

• nix unify module: Allows using NixOS services and configuration on non-NixOS hosts
  • deployment works using nixos-rebuild
• ansible module: module that allows reading ansible variables from the environment variable ANSIBLE_JSON
• ansible roles:
  • local_nix: installs nix-portable and nix-wrapper, which uses nix-portable if no local nix install is found (meant for local usage)
  • nix: installs nix in multi-user mode (meant for server usage)
  • nixos_rebuild: runs nixos-rebuild and deploys the configuration on the host (meant for local usage)
    • can be used with both pure nixos and nix-unify system configurations

Usage (nix-unify)

Add nix-unify to your flake.nix

  inputs.nix-unify.url = "github:mgit-at/nix-unify/master";
  inputs.nix-unify.inputs.nixpkgs.follows = "nixpkgs";

Add nix-unify.nixosModules.unify to the nixos configuration that you want to convert

Use nixos-rebuild .#your-config --target-host user@host to deploy the configuration

Adding a nixos flake.nix to your ansible repo

flake.nix:

{
  description = "My company ansible";

  inputs.nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
  inputs.nix-unify.url = "github:mgit-at/nix-unify/master";
  inputs.nix-unify.inputs.nixpkgs.follows = "nixpkgs";

  outputs = { self, nixpkgs, nix-unify }@inputs: let
    inherit (self) outputs;
  in {
    nixosConfigurations = nixpkgs.lib.mapAttrs (host: _: nixpkgs.lib.nixosSystem {
      specialArgs = {
        inherit inputs outputs;
      };
      modules = [
        "${./.}/nixos/hosts/${host}"
      ];
    }) (builtins.readDir ./nixos/hosts);
  };
}

For each individual host add a ./nixos/hosts/HOST/default.nix. Template:

{ config, pkgs, lib, inputs, ... }:

with lib;

{
  imports = [
    inputs.nix-unify.nixosModules.unify
    inputs.nix-unify.nixosModules.ansible
  ];

  environment.systemPackages = with pkgs; [
    # add packages here
    curl
  ];

  networking.hostName = "your-hostname";
  nixpkgs.hostPlatform = "x86_64-linux";
}

API

tbd

Usage (ansible module)

Add nix-unify to your flake.nix

  inputs.nix-unify.url = "github:mgit-at/nix-unify/master";
  inputs.nix-unify.inputs.nixpkgs.follows = "nixpkgs";

Add nix-unify.nixosModules.ansible to the nixos configuration

Either set ANSIBLE_JSON manually or use the nixos-rebuild role

Usage (ansible roles)

Install the collection using ansible-galaxy

ansible-galaxy collection install mgit_at.nix_unify

• local_nix: Include before any nixos-rebuild roles
• nix: Include on non-nixos hosts that will be managed by nix-unify
• nixos_rebuild: Include for nix-unify and nixos deployments
  • Requires local_nix or nix_wrapper being set to env (effectivly no wrapper)
  • Note that this role depends on a fully configured flake being present in the repo that exposes the given system configurations