make option out of stateVersion

machines/luna/configuration.nix

@@ -6,10 +6,9 @@
   ];
 
   horseman.username = "horseman";
+  horseman.stateVersion = "24.11";
 
   networking.hostName = "luna";
 
   networking.extraHosts = "127.0.0.1 koala.rails.local";
-
-  system.stateVersion = "24.11";
 }

machines/solis/configuration.nix

@@ -6,10 +6,9 @@
   ];
 
   horseman.username = "horseman";
+  horseman.stateVersion = "24.11";
 
   networking.hostName = "solis";
 
   networking.firewall.allowedTCPPorts = [3000 3001];
-
-  system.stateVersion = "24.11";
 }

machines/terra/configuration.nix

@@ -6,8 +6,7 @@
   ];
 
   horseman.username = "horseman";
+  horseman.stateVersion = "24.11";
 
   networking.hostName = "terra";
-
-  system.stateVersion = "24.11";
 }

modules/base/nix.nix

@@ -7,6 +7,7 @@
 }: let
   inherit (lib) mkEnableOption mkIf;
   cfg = config.horseman.base.nix;
+  stateVersion = config.horseman.stateVersion;
 in {
   options = {
     horseman.base.nix = {
@@ -40,5 +41,7 @@ in {
       experimental-features = "nix-command flakes";
       auto-optimise-store = true;
     };
+
+    system.stateVersion = stateVersion;
   };
 }

modules/default.nix

@@ -15,6 +15,7 @@ in {
   options = {
     horseman = {
       username = mkOption {type = types.str;};
+      stateVersion = mkOption { type = types.str; };
     };
   };
 }

modules/users/default.nix

@@ -8,6 +8,7 @@
   inherit (lib) mkEnableOption mkIf;
   cfg = config.horseman.users.default;
   username = config.horseman.username;
+  stateVersion = config.horseman.stateVersion;
 in {
   options = {
     horseman.users.default = {
@@ -22,7 +23,7 @@ in {
         home = {
           username = username;
           homeDirectory = "/home/${username}";
-          stateVersion = "24.11";
+          stateVersion = stateVersion;
         };
 
         programs = {