Theme btop and Homepage via matugen on the mediaserver

Share the wallpaper symlink across all hosts by moving it from gnome.nix
into home-manager/fred.nix, and add matugen templates for btop and the
Homepage dashboard.

The Homepage NixOS module writes custom.css into /etc (read-only), so
bind-mount /var/lib/homepage-custom-css/custom.css over it. A systemd
path unit restarts homepage-dashboard whenever matugen rewrites the
file, so regeneration works without sudo.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

home-manager/fred.nix

@@ -14,9 +14,21 @@
     { allowUnfree = true; }
   '';
 
+  # Wallpaper — source of truth for matugen on all hosts
+  home.file.".local/share/backgrounds/wallpaper.png".source =
+    "${inputs.self}/walls/wallpaper.png";
+
   # Ensure Ghostty themes directory exists for matugen
   home.file.".config/ghostty/themes/.keep".text = "";
 
+  # btop config — use matugen-generated theme
+  home.file.".config/btop/btop.conf".text = ''
+    color_theme = "matugen"
+    theme_background = False
+    vim_keys = False
+  '';
+  home.file.".config/btop/themes/.keep".text = "";
+
   # Ghostty config
   home.file.".config/ghostty/config".force = true;
   home.file.".config/ghostty/config".text = ''
@@ -73,6 +85,14 @@
     input_path = "${inputs.self}/templates/recolor-folders.sh"
     output_path = "${config.home.homeDirectory}/.local/share/matugen/recolor-folders.sh"
     post_hook = "bash ${config.home.homeDirectory}/.local/share/matugen/recolor-folders.sh"
+
+    [templates.btop]
+    input_path = "${inputs.self}/templates/btop.theme"
+    output_path = "${config.home.homeDirectory}/.config/btop/themes/matugen.theme"
+
+    [templates.homepage]
+    input_path = "${inputs.self}/templates/homepage.css"
+    output_path = "/var/lib/homepage-custom-css/custom.css"
   '';
 
 }

hosts/FredOS-Mediaserver.nix

@@ -17,6 +17,7 @@
       screen
       yt-dlp
       ghostty.terminfo
+      matugen
       (pkgs.writeShellScriptBin "transcode-hevc" ''
         export PATH="${pkgs.jellyfin-ffmpeg}/bin:${pkgs.coreutils}/bin:${pkgs.findutils}/bin:${pkgs.gnugrep}/bin:${pkgs.gawk}/bin:${pkgs.bc}/bin:${pkgs.curl}/bin:$PATH"
         exec ${pkgs.bash}/bin/bash ${../scripts/transcode-hevc.sh} "$@"

services/homepage.nix

@@ -60,6 +60,32 @@ in
 {
   config = lib.mkIf (config.networking.hostName == "FredOS-Mediaserver") {
 
+    # Writable location for matugen-generated custom.css; bind-mounted into
+    # the homepage service namespace over the Nix-managed /etc path.
+    systemd.tmpfiles.rules = [
+      "d /var/lib/homepage-custom-css 0755 fred users -"
+      "f /var/lib/homepage-custom-css/custom.css 0644 fred users -"
+    ];
+
+    systemd.services.homepage-dashboard.serviceConfig.BindPaths = [
+      "/var/lib/homepage-custom-css/custom.css:/etc/homepage-dashboard/custom.css"
+    ];
+
+    # Auto-restart homepage when matugen rewrites the custom.css
+    systemd.paths.homepage-css-reload = {
+      description = "Watch matugen custom.css for changes";
+      wantedBy = [ "multi-user.target" ];
+      pathConfig.PathChanged = "/var/lib/homepage-custom-css/custom.css";
+    };
+
+    systemd.services.homepage-css-reload = {
+      description = "Restart homepage after custom.css changes";
+      serviceConfig = {
+        Type = "oneshot";
+        ExecStart = "${pkgs.systemd}/bin/systemctl restart homepage-dashboard.service";
+      };
+    };
+
     # Oneshot service that extracts API keys and writes /etc/homepage-secrets
     systemd.services.homepage-extract-secrets = {
       description = "Extract API keys for Homepage dashboard";

settings/gnome.nix

@@ -64,9 +64,6 @@
 
     # Home Manager GNOME settings
     home-manager.users.fred = { config, lib, ... }: {
-      home.file.".local/share/backgrounds/wallpaper.png".source =
-        "${inputs.self}/walls/wallpaper.png";
-
       # Minimal titlebars — hide window buttons and shrink headerbar
       home.file.".config/gtk-4.0/gtk.css".force = true;
       home.file.".config/gtk-4.0/gtk.css".text = ''

templates/btop.theme

@@ -0,0 +1,54 @@
+# Matugen-generated btop theme based on wallpaper
+
+theme[main_bg]="{{colors.surface.default.hex}}"
+theme[main_fg]="{{colors.on_surface.default.hex}}"
+theme[title]="{{colors.on_surface.default.hex}}"
+theme[hi_fg]="{{colors.primary.default.hex}}"
+theme[selected_bg]="{{colors.surface_container_high.default.hex}}"
+theme[selected_fg]="{{colors.primary.default.hex}}"
+theme[inactive_fg]="{{colors.on_surface_variant.default.hex}}"
+theme[graph_text]="{{colors.on_surface.default.hex}}"
+theme[meter_bg]="{{colors.surface_container.default.hex}}"
+theme[proc_misc]="{{colors.tertiary.default.hex}}"
+
+theme[cpu_box]="{{colors.outline.default.hex}}"
+theme[mem_box]="{{colors.outline.default.hex}}"
+theme[net_box]="{{colors.outline.default.hex}}"
+theme[proc_box]="{{colors.outline.default.hex}}"
+theme[div_line]="{{colors.outline_variant.default.hex}}"
+
+theme[temp_start]="{{colors.tertiary.default.hex}}"
+theme[temp_mid]="{{colors.secondary.default.hex}}"
+theme[temp_end]="{{colors.error.default.hex}}"
+
+theme[cpu_start]="{{colors.primary.default.hex}}"
+theme[cpu_mid]="{{colors.secondary.default.hex}}"
+theme[cpu_end]="{{colors.tertiary.default.hex}}"
+
+theme[free_start]="{{colors.primary.default.hex}}"
+theme[free_mid]="{{colors.secondary.default.hex}}"
+theme[free_end]="{{colors.tertiary.default.hex}}"
+
+theme[cached_start]="{{colors.primary.default.hex}}"
+theme[cached_mid]="{{colors.secondary.default.hex}}"
+theme[cached_end]="{{colors.tertiary.default.hex}}"
+
+theme[available_start]="{{colors.primary.default.hex}}"
+theme[available_mid]="{{colors.secondary.default.hex}}"
+theme[available_end]="{{colors.tertiary.default.hex}}"
+
+theme[used_start]="{{colors.primary.default.hex}}"
+theme[used_mid]="{{colors.secondary.default.hex}}"
+theme[used_end]="{{colors.tertiary.default.hex}}"
+
+theme[download_start]="{{colors.primary.default.hex}}"
+theme[download_mid]="{{colors.secondary.default.hex}}"
+theme[download_end]="{{colors.tertiary.default.hex}}"
+
+theme[upload_start]="{{colors.primary.default.hex}}"
+theme[upload_mid]="{{colors.secondary.default.hex}}"
+theme[upload_end]="{{colors.tertiary.default.hex}}"
+
+theme[process_start]="{{colors.primary.default.hex}}"
+theme[process_mid]="{{colors.secondary.default.hex}}"
+theme[process_end]="{{colors.tertiary.default.hex}}"

templates/homepage.css

@@ -0,0 +1,69 @@
+/* Matugen-generated Homepage theme based on wallpaper */
+
+/* Background + text for the whole dashboard */
+html, body, main, .information-widget {
+  background-color: {{colors.surface.default.hex}} !important;
+  color: {{colors.on_surface.default.hex}} !important;
+}
+
+/* Service and widget cards */
+#information-widgets > *,
+.services-group .service,
+.bookmark-group .bookmark,
+.information-widget-datetime,
+.information-widget-resources,
+.information-widget-search {
+  background-color: {{colors.surface_container.default.hex}} !important;
+  color: {{colors.on_surface.default.hex}} !important;
+  border-color: {{colors.outline_variant.default.hex}} !important;
+}
+
+/* Group headings */
+h1, h2, h3, .services-group h2, .bookmark-group h2 {
+  color: {{colors.on_surface.default.hex}} !important;
+}
+
+/* Muted / secondary text */
+.service-description, .bookmark-description,
+.service .service-sub, .information-widget .label {
+  color: {{colors.on_surface_variant.default.hex}} !important;
+}
+
+/* Search input */
+input, .search input[type="text"] {
+  background-color: {{colors.surface_container_high.default.hex}} !important;
+  color: {{colors.on_surface.default.hex}} !important;
+  border-color: {{colors.outline.default.hex}} !important;
+}
+
+/* Accent — used on highlights, progress bars, links */
+a, .service a:hover, .bookmark a:hover,
+.resources .resource .progress .progress-bar,
+button:hover, .service-container:hover {
+  color: {{colors.primary.default.hex}} !important;
+}
+
+.resources .resource .progress .progress-bar,
+.resources .resource .usage-bar-fill {
+  background-color: {{colors.primary.default.hex}} !important;
+}
+
+/* Dividers */
+hr, .service-container, .bookmark-container {
+  border-color: {{colors.outline_variant.default.hex}} !important;
+}
+
+/* Override Tailwind's slate palette so built-in theme uses wallpaper colors */
+:root {
+  --color-slate-50: {{colors.on_surface.default.hex}};
+  --color-slate-100: {{colors.on_surface.default.hex}};
+  --color-slate-200: {{colors.on_surface.default.hex}};
+  --color-slate-300: {{colors.on_surface_variant.default.hex}};
+  --color-slate-400: {{colors.on_surface_variant.default.hex}};
+  --color-slate-500: {{colors.outline.default.hex}};
+  --color-slate-600: {{colors.outline_variant.default.hex}};
+  --color-slate-700: {{colors.surface_container_high.default.hex}};
+  --color-slate-800: {{colors.surface_container.default.hex}};
+  --color-slate-900: {{colors.surface.default.hex}};
+  --color-slate-950: {{colors.surface.default.hex}};
+}