Initial commit

flake/den/templates/default/modules/aspects/alice.nix

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+{ den, eg, ... }:
+{
+  den.aspects.alice = {
+
+    # Alice can include other aspects.
+    # For small, private one-shot aspects, use let-bindings like here.
+    # for more complex or re-usable ones, define on their own modules,
+    # as part of any aspect-subtree.
+    includes =
+      let
+        # deadnix: skip # not required, showcasing angle-brackets syntax.
+        inherit (den.lib) __findFile;
+
+        customEmacs.homeManager =
+          { pkgs, ... }:
+          {
+            programs.emacs.enable = true;
+            programs.emacs.package = pkgs.emacs30-nox;
+          };
+      in
+      [
+        # from local bindings.
+        customEmacs
+        # from the aspect tree, cooper example is defined bellow
+        den.aspects.cooper
+        den.aspects.setHost
+        # from the `eg` namespace.
+        eg.autologin
+        # den included batteries that provide common configs.
+        <den/primary-user> # alice is admin always.
+        (<den/user-shell> "fish") # default user shell
+      ];
+
+    # Alice configures NixOS hosts it lives on.
+    nixos =
+      { pkgs, ... }:
+      {
+        users.users.alice.packages = [ pkgs.vim ];
+      };
+
+    # Alice home-manager.
+    homeManager =
+      { pkgs, ... }:
+      {
+        home.packages = [ pkgs.htop ];
+      };
+
+    # <user>.provides.<host>, via eg/routes.nix
+    provides.igloo =
+      { host, ... }:
+      {
+        nixos.programs.nh.enable = host.name == "igloo";
+      };
+  };
+
+  # This is a context-aware aspect, that emits configurations
+  # **anytime** at least the `user` data is in context.
+  # read more at https://vic.github.io/den/context-aware.html
+  den.aspects.cooper =
+    { user, ... }:
+    {
+      nixos.users.users.${user.userName}.description = "Alice Cooper";
+    };
+
+  den.aspects.setHost =
+    { host, ... }:
+    {
+      networking.hostName = host.hostName;
+    };
+}

flake/den/templates/default/modules/aspects/defaults.nix

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+{
+  config,
+  # deadnix: skip # enable <den/brackets> syntax for demo.
+  __findFile ? __findFile,
+  den,
+  ...
+}:
+{
+  # Lets also configure some defaults using aspects.
+  # These are global static settings.
+  den.default = {
+    darwin.system.stateVersion = 6;
+    nixos.system.stateVersion = "25.05";
+    homeManager.home.stateVersion = "25.05";
+  };
+
+  # These are functions that produce configs
+  den.default.includes = [
+    # ${user}.provides.${host} and ${host}.provides.${user}
+    <eg/routes>
+
+    # Enable home-manager on all hosts.
+    <den/home-manager>
+
+    # Automatically create the user on host.
+    <den/define-user>
+
+    # Disable booting when running on CI on all NixOS hosts.
+    (if config ? _module.args.CI then <eg/ci-no-boot> else { })
+
+    # NOTE: be cautious when adding fully parametric functions to defaults.
+    # defaults are included on EVERY host/user/home, and IF you are not careful
+    # you could be duplicating config values. For example:
+    #
+    #  # This will append 42 into foo option for the {host} and for EVERY {host,user}
+    #  ({ host, ... }: { nixos.foo = [ 42 ]; }) # DO-NOT-DO-THIS.
+    #
+    #  # Instead try to be explicit if a function is intended for ONLY { host }.
+    (den.lib.take.exactly (
+      # deadnix: skip
+      { OS, host }:
+      {
+        nixos.networking.hostName = host.hostName;
+      }
+    ))
+
+  ];
+}

flake/den/templates/default/modules/aspects/eg/autologin.nix

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+{
+  # autologin is context-aware, parametric aspect.
+  # it applies only if the context has at least { user }
+  # meaning that has access to user data
+  eg.autologin =
+    { user, ... }:
+    {
+      nixos =
+        { config, lib, ... }:
+        lib.mkIf config.services.displayManager.enable {
+          services.displayManager.autoLogin.enable = true;
+          services.displayManager.autoLogin.user = user.userName;
+        };
+    };
+}

flake/den/templates/default/modules/aspects/eg/ci-no-boot.nix

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+{
+  eg.ci-no-boot = {
+    description = "Disables booting during CI";
+    nixos = {
+      boot.loader.grub.enable = false;
+      fileSystems."/".device = "/dev/null";
+    };
+  };
+}

flake/den/templates/default/modules/aspects/eg/routes.nix

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+# This example implements an aspect "routing" pattern.
+#
+# Unlike `den.default` which is `parametric.atLeast`
+# we use `parametric.fixedTo` here, which help us
+# propagate an already computed context to all includes.
+#
+# This aspect, when installed in a `parametric.atLeast`
+# will just forward the same context.
+# The `mutual` helper returns an static configuration which
+# is ignored by parametric aspects, thus allowing
+# non-existing aspects to be just ignored.
+#
+# Be sure to read: https://vic.github.io/den/dependencies.html
+# See usage at: defaults.nix, alice.nix, igloo.nix
+#
+{ den, eg, ... }:
+{
+  # Usage: `den.default.includes [ eg.routes ]`
+  eg.routes =
+    let
+      inherit (den.lib) parametric;
+
+      # eg, `<user>._.<host>` and `<host>._.<user>`
+      mutual = from: to: den.aspects.${from.aspect}._.${to.aspect} or { };
+
+      routes =
+        { host, user, ... }@ctx:
+        {
+          __functor = parametric.fixedTo ctx;
+          includes = [
+            (mutual user host)
+            (mutual host user)
+          ];
+        };
+    in
+    routes;
+}

flake/den/templates/default/modules/aspects/eg/vm-bootable.nix

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+let
+  installer = variant: {
+    nixos =
+      { modulesPath, ... }:
+      {
+        imports = [ (modulesPath + "/installer/cd-dvd/installation-cd-${variant}.nix") ];
+      };
+  };
+in
+{
+  # make USB/VM installers.
+  eg.vm-bootable.provides = {
+    tui = installer "minimal";
+    gui = installer "graphical-base";
+  };
+}

flake/den/templates/default/modules/aspects/eg/vm.nix

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+{ eg, ... }:
+{
+  eg.vm.provides = {
+    gui.includes = [
+      eg.vm
+      eg.vm-bootable._.gui
+      eg.xfce-desktop
+    ];
+
+    tui.includes = [
+      eg.vm
+      eg.vm-bootable._.tui
+    ];
+  };
+}

flake/den/templates/default/modules/aspects/eg/xfce-desktop.nix

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+{
+  eg.xfce-desktop.nixos =
+    { lib, ... }:
+    {
+      # https://gist.github.com/nat-418/1101881371c9a7b419ba5f944a7118b0
+      services.xserver = {
+        enable = true;
+        desktopManager = {
+          xterm.enable = false;
+          xfce.enable = true;
+        };
+      };
+
+      services.displayManager = {
+        defaultSession = lib.mkDefault "xfce";
+        enable = true;
+      };
+    };
+}

flake/den/templates/default/modules/aspects/igloo.nix

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+{
+  den.aspects.igloo = {
+    # igloo host provides some home-manager defaults to its users.
+    homeManager.programs.direnv.enable = true;
+
+    # NixOS configuration for igloo.
+    nixos =
+      { pkgs, ... }:
+      {
+        environment.systemPackages = [ pkgs.hello ];
+      };
+
+    # <host>.provides.<user>, via eg/routes.nix
+    provides.alice =
+      { user, ... }:
+      {
+        homeManager.programs.helix.enable = user.name == "alice";
+      };
+  };
+}