From 2a63bee83b70e8d963fff451a02323772c736cf5 Mon Sep 17 00:00:00 2001
From: Pim Kunis <pim@kunis.nl>
Date: Mon, 4 Nov 2024 22:27:24 +0100
Subject: [PATCH] Implement raspberry pi check using nixos-facter

---
 machines/default.nix           |  5 -----
 machines/warwick/default.nix   | 19 ++++++++++++-------
 modules/default.nix            | 34 ++++++++++++++++------------------
 modules/facter.nix             | 15 +++++++++++++++
 modules/networking/default.nix |  5 +++--
 5 files changed, 46 insertions(+), 32 deletions(-)
 create mode 100644 modules/facter.nix

diff --git a/machines/default.nix b/machines/default.nix
index 9a0c0c8..c32a0b4 100644
--- a/machines/default.nix
+++ b/machines/default.nix
@@ -25,11 +25,6 @@ flake-utils.lib.eachDefaultSystem (system: let
         '';
       };
 
-      isRaspberryPi = lib.mkOption {
-        default = false;
-        type = lib.types.bool;
-      };
-
       nixosModule = lib.mkOption {
         default = {...}: {};
         type = lib.types.anything;
diff --git a/machines/warwick/default.nix b/machines/warwick/default.nix
index ac0caaa..0035e27 100644
--- a/machines/warwick/default.nix
+++ b/machines/warwick/default.nix
@@ -1,16 +1,21 @@
 {
   machines.warwick = {
     arch = "aarch64-linux";
-    isRaspberryPi = true;
     facterReportPath = ./facter.json;
 
-    nixosModule.lab = {
-      storage.profile = "pi";
-      monitoring.server.enable = true;
+    nixosModule = {inputs, ...}: {
+      imports = [inputs.nixos-hardware.nixosModules.raspberry-pi-4];
 
-      tailscale = {
-        advertiseExitNode = true;
-        enable = true;
+      config = {
+        lab = {
+          storage.profile = "pi";
+          monitoring.server.enable = true;
+
+          tailscale = {
+            advertiseExitNode = true;
+            enable = true;
+          };
+        };
       };
     };
   };
diff --git a/modules/default.nix b/modules/default.nix
index a595904..99e0605 100644
--- a/modules/default.nix
+++ b/modules/default.nix
@@ -1,28 +1,26 @@
 {
   self,
   pkgs,
-  config,
   lib,
   inputs,
   machine,
+  config,
   ...
 }: {
-  imports =
-    [
-      ./storage.nix
-      ./backups.nix
-      ./networking
-      ./data-sharing.nix
-      ./monitoring
-      ./k3s
-      ./tailscale.nix
-      machine.nixosModule
-      inputs.disko.nixosModules.disko
-      inputs.sops-nix.nixosModules.sops
-      inputs.nix-snapshotter.nixosModules.nix-snapshotter
-      inputs.nixos-facter-modules.nixosModules.facter
-    ]
-    ++ lib.lists.optional (machine.isRaspberryPi) inputs.nixos-hardware.nixosModules.raspberry-pi-4;
+  imports = [
+    ./storage.nix
+    ./backups.nix
+    ./networking
+    ./data-sharing.nix
+    ./monitoring
+    ./k3s
+    ./tailscale.nix
+    ./facter.nix
+    machine.nixosModule
+    inputs.disko.nixosModules.disko
+    inputs.sops-nix.nixosModules.sops
+    inputs.nix-snapshotter.nixosModules.nix-snapshotter
+  ];
 
   config = {
     time.timeZone = "Europe/Amsterdam";
@@ -107,7 +105,7 @@
       fastfetch
     ];
 
-    boot = lib.mkIf (! machine.isRaspberryPi) {
+    boot = lib.mkIf (! config.facter.lab.isRaspberryPi) {
       loader = {
         systemd-boot.enable = lib.mkDefault true;
         efi.canTouchEfiVariables = true;
diff --git a/modules/facter.nix b/modules/facter.nix
new file mode 100644
index 0000000..2ee214d
--- /dev/null
+++ b/modules/facter.nix
@@ -0,0 +1,15 @@
+{
+  inputs,
+  lib,
+  config,
+  ...
+}: {
+  imports = [inputs.nixos-facter-modules.nixosModules.facter];
+
+  options.facter.lab = {
+    isRaspberryPi = lib.mkOption {
+      type = lib.types.bool;
+      default = config.facter.report.system == "aarch64-linux";
+    };
+  };
+}
diff --git a/modules/networking/default.nix b/modules/networking/default.nix
index 0f235cc..ef68c4e 100644
--- a/modules/networking/default.nix
+++ b/modules/networking/default.nix
@@ -1,5 +1,6 @@
 {
   lib,
+  config,
   machine,
   ...
 }: {
@@ -16,7 +17,7 @@
       enable = true;
 
       networks = lib.attrsets.mergeAttrsList [
-        (lib.optionalAttrs (! machine.isRaspberryPi) {
+        (lib.optionalAttrs (! config.facter.lab.isRaspberryPi) {
           "30-main-nic" = {
             matchConfig.Name = "en*";
 
@@ -25,7 +26,7 @@
             };
           };
         })
-        (lib.optionalAttrs machine.isRaspberryPi {
+        (lib.optionalAttrs config.facter.lab.isRaspberryPi {
           "30-main-nic" = {
             matchConfig.Name = "end*";
             networkConfig = {