Add role for gnuplot.

nix/configuration/configuration.nix

@@ -65,6 +65,7 @@
     ./roles/nix_index
     ./roles/flux
     ./roles/tekton
+    ./roles/gnuplot
   ];
 
   nix.settings.experimental-features = [

nix/configuration/hosts/odo/default.nix

@@ -40,6 +40,7 @@
   me.firefox.enable = true;
   me.flux.enable = true;
   me.git.config = ../../roles/git/files/gitconfig_home;
+  me.gnuplot.enable = true;
   me.gpg.enable = true;
   me.graphical = true;
   me.graphics_card_type = "amd";

nix/configuration/roles/gnuplot/default.nix

@@ -0,0 +1,29 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+
+{
+  imports = [ ];
+
+  options.me = {
+    gnuplot.enable = lib.mkOption {
+      type = lib.types.bool;
+      default = false;
+      example = true;
+      description = "Whether we want to install gnuplot.";
+    };
+  };
+
+  config = lib.mkIf config.me.gnuplot.enable (
+    lib.mkMerge [
+      {
+        environment.systemPackages = with pkgs; [
+          gnuplot
+        ];
+      }
+    ]
+  );
+}