Add GPG config for git signing

flake.nix

@@ -58,7 +58,6 @@
           host = "laptop";
           profile = "desktop";
           username = "josh";
-          gpgSigningKey = "0x530DA0331EFE99F5";
         in nixpkgs.lib.nixosSystem {
           inherit system;
           specialArgs = {
@@ -66,7 +65,6 @@
             inherit host;
             inherit profile;
             inherit username;
-            inherit gpgSigningKey;
           };
           pkgs = pkgs;
           modules = [
@@ -103,7 +101,6 @@
             inherit host;
             inherit profile;
             inherit username;
-          
           };
           pkgs = pkgs;
           modules = [

homes/josh/home.nix

@@ -1,4 +1,6 @@
 {
+  config,
+  gpgSigningKey,
   lib,
   pkgs,
   profile,
@@ -25,6 +27,23 @@ with lib;
     ];
   };
 
+  programs.git = {
+    enable = true;
+    settings = {
+      user = {
+        name = "Joshua Yuen";
+        email = "joshuayuen99@gmail.com";
+        # We need to do this to pass through the (optional) signing key from the hosts/* file
+        signingkey = if gpgSigningKey != "" then gpgSigningKey else config.modules.gpg.signingKey;
+      };
+      commit.gpgsign = true;
+      init.defaultBranch = "main";
+    };
+  };
+
+  # Enable GPG-agent for git signing
+  modules.gpg.enable = true;
+
   # Let Home Manager install and manage itself
   programs.home-manager.enable = true;
 

hosts/laptop/default.nix

@@ -12,4 +12,6 @@
     ./hardware.nix
     ./host-packages.nix
   ];
+
+  modules.gpg.signingKey = "0x530DA0331EFE99F5";
 }

modules/core/user.nix

@@ -24,6 +24,7 @@ in
         profile
         username
         ;
+      gpgSigningKey = config.modules.gpg.signingKey;
     };
     users.${username} = {
       imports = [ ../../homes/${username}/home.nix ];

modules/homes/default.nix

@@ -5,6 +5,7 @@
   imports = [
     ./direnv.nix
     ./firefox.nix
+    ./gpg.nix
     ./fzf.nix
     ./hyprland
     ./kitty.nix

modules/homes/gpg.nix

@@ -0,0 +1,31 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+with lib;
+let
+  cfg = config.modules.gpg;
+in
+{
+  config = mkIf cfg.enable {
+    services = {
+      gpg-agent = {
+        enable = true;
+        enableSshSupport = true;
+        enableBashIntegration = true;
+        enableZshIntegration = true;
+        pinentry.package = pkgs.pinentry-qt;
+      };
+    };
+
+    home.packages = [ pkgs.gnupg ];
+
+    programs = {
+      gpg = {
+        enable = true;
+      };
+    };
+  };
+}

modules/options/default.nix

@@ -4,6 +4,7 @@
 {
   imports = [
     ./displayManager.nix
+    ./gpg.nix
     ./hyprland.nix
     ./localsend.nix
     ./pipewire.nix

modules/options/gpg.nix

@@ -0,0 +1,19 @@
+{
+  lib,
+  ...
+}:
+with lib;
+{
+  options.modules.gpg = {
+    enable = mkEnableOption {
+      default = false;
+      description = "Enable gpg-agent";
+    };
+
+    signingKey = mkOption {
+      type = types.str;
+      default = "";
+      description = "The key ID to sign with for git";
+    };
+  };
+}