Migrate to flakes

configuration.nix

@@ -1,4 +1,4 @@
-{ config, pkgs, lib, ... }:
+{ config, inputs, pkgs, lib, ... }:
 
 with pkgs;
 
@@ -30,7 +30,13 @@ with pkgs;
     '';
   };
 
-  environment.systemPackages = [ libraspberrypi htop vim ];
+  environment.systemPackages = [
+    libraspberrypi
+    htop
+    neovim
+    git
+    inputs.agenix.defaultPackage.aarch64-linux
+  ];
 
   # Load PWM hardware timers
   boot.kernelModules = [ "pwm_bcm2835" "w1-gpio" "w1-therm" ];
@@ -103,7 +109,7 @@ with pkgs;
     allowReboot = true;
   };
 
-  # Run Nix garbage collector, while avoiding recompilation
+  # Run Nix garbage collector, while avoiding recompilation and enable flakes
   nix = {
     settings.auto-optimise-store = true;
     gc = {
@@ -114,9 +120,15 @@ with pkgs;
       keep-outputs = true
       keep-derivations = true
       gc-keep-outputs = true
+      experimental-features = nix-command flakes
     '';
+    package = nixFlakes;
   };
 
+  # Use same version of nixpkgs for nix-shell
+  nix.nixPath = let path = toString ./.;
+  in [ "nixpkgs=${inputs.nixpkgs}" "nixos-config=${path}/configuration.nix" ];
+
   # Configure fish shell
   programs.fish.enable = true;
   users.users.root = {
@@ -138,6 +150,25 @@ with pkgs;
   # NixOS version
   system.stateVersion = "22.05";
 
+  # Specify secrets
+  age = {
+    secrets.wireguard.file = secrets/wireguard.age;
+    secrets.syncthing.file = secrets/syncthing.age;
+    secrets.msmtp.file = secrets/msmtp.age;
+    secrets.gitea = {
+      file = secrets/gitea.age;
+      owner = "gitea";
+      group = "gitea";
+    };
+    secrets.ddclient.file = secrets/ddclient.age;
+    secrets.miniflux = {
+      file = secrets/miniflux.age;
+      owner = "miniflux";
+      group = "miniflux";
+    };
+    identityPaths = [ "/etc/ssh/id_ed25519" ];
+  };
+
   # Import other configuration modules
   imports = [
     ./modules/hardware-configuration.nix