define primary Linux username in base-user.nix

hosts/pi3bplus/configuration.nix

@@ -1,4 +1,7 @@
 { config, pkgs, lib, ... }:
+let
+  user = config.yoda.user;
+in
 {
   imports =
     [ # Include the results of the hardware scan.
@@ -45,9 +48,9 @@
   };
 
   # Define a user account. Don't forget to set a password with 'passwd'.
-  users.users."yoda" = {
+  users.users."${user}" = {
     isNormalUser = true;
-    description = "Yoda";
+    description = "${user}";
     extraGroups = [ "wheel" ]; # Enable 'sudo' for the user.
   };
 

hosts/yodaNas/notify-change.nix

@@ -1,8 +1,10 @@
 { config, pkgs, ...}:
 let
+  user = config.yoda.user;
+
   name = "notify-change";
   subdir = "readonly-git/notify-change";
-  fulldir = "/home/yoda/${subdir}";
+  fulldir = "/home/${user}/${subdir}";
 
   jdk = pkgs.jdk23;
   gradle = pkgs.gradle.override {
@@ -16,7 +18,7 @@ in
     # comma-separated list of email addresses
     keyFile = ../../secrets/${name}-email-recipients;
     destDir = "/secrets";
-    user = "yoda";
+    user = "${user}";
     #group = "smtpd"; # Default: root
     permissions = "0400";
     uploadAt = "pre-activation";
@@ -25,7 +27,7 @@ in
   deployment.keys."${name}-EMAIL_USER" = {
     keyFile = ../../secrets/user.web.de;
     destDir = "/secrets";
-    user = "yoda";
+    user = "${user}";
     #group = "smtpd"; # Default: root
     permissions = "0400";
     uploadAt = "pre-activation";
@@ -34,7 +36,7 @@ in
   deployment.keys."${name}-EMAIL_PASSWORD" = {
     keyFile = ../../secrets/pwd.web.de;
     destDir = "/secrets";
-    user = "yoda";
+    user = "${user}";
     #group = "smtpd"; # Default: root
     permissions = "0400";
     uploadAt = "pre-activation";
@@ -43,7 +45,7 @@ in
   deployment.keys."${name}-ILIAS_USER" = {
     keyFile = ../../secrets/user.ilias.uni-marburg.de;
     destDir = "/secrets";
-    user = "yoda";
+    user = "${user}";
     #group = "smtpd"; # Default: root
     permissions = "0400";
     uploadAt = "pre-activation";
@@ -52,14 +54,14 @@ in
   deployment.keys."${name}-ILIAS_PASSWORD" = {
     keyFile = ../../secrets/pwd.ilias.uni-marburg.de;
     destDir = "/secrets";
-    user = "yoda";
+    user = "${user}";
     #group = "smtpd"; # Default: root
     permissions = "0400";
     uploadAt = "pre-activation";
   };
 
   # Download notify-change Git repository.
-#  home-manager.users.yoda = { osConfig, config, pkgs, ... }: {
+#  home-manager.users."${user}" = { osConfig, config, pkgs, ... }: {
 #    home.file."${subdir}".source = (builtins.fetchGit {
 #      url = "https://codeberg.org/privacy1st/selenium-webdriver-ide-demo";
 #      ref = "changedetection";
@@ -87,7 +89,7 @@ in
     serviceConfig = {
       Type = "oneshot";
       PrivateTmp = true;
-      User = "yoda";
+      User = "${user}";
     };
     path = [
       pkgs.bash # todo

hosts/yodaYoga/BikeTripPlanner.nix

@@ -1,4 +1,7 @@
 { config, pkgs, ... }:
+let
+  user = config.yoda.user;
+in
 {
   imports = [
     ../../modules/headless.nix
@@ -13,7 +16,7 @@
   ];
 
   # Download BikeTripPlanner Git repository.
-  home-manager.users."yoda" = { osConfig, config, pkgs, ... }: {
+  home-manager.users."${user}" = { osConfig, config, pkgs, ... }: {
     home.file."readonly-git/BikeTripPlanner".source = (builtins.fetchGit {
       url = "https://github.com/langbein-daniel/BikeTripPlanner";
       #rev = "6d4daf18235189825b0c314901b1617ece6d8641";
@@ -31,7 +34,7 @@
       docker
     ];
     script = ''
-      docker compose -f /home/yoda/readonly-git/BikeTripPlanner/deployment/btp-only.yml up -d --wait
+      docker compose -f /home/${user}/readonly-git/BikeTripPlanner/deployment/btp-only.yml up -d --wait
     '';
     # Start after login.
     wantedBy = [ "multi-user.target" ];

modules/android.nix

@@ -1,10 +1,13 @@
 { config, pkgs, ... }:
+let
+  user = config.yoda.user;
+in
 {
   # adb and fastboot
 
   # https://nixos.wiki/wiki/Android#adb_setup
   programs.adb.enable = true;
-  users.users."yoda".extraGroups = [ "adbusers" "plugdev" ];
+  users.users."${user}".extraGroups = [ "adbusers" "plugdev" ];
 
   # plugdev group: https://developer.android.com/studio/run/device
   # How to add user to new group: https://superuser.com/a/1352988

modules/base-minimal.nix

@@ -1,6 +1,11 @@
 { config, pkgs, ... }:
+let
+  user = config.yoda.user;
+in
 {
   imports = [
+    ./base-user.nix
+
     # Filesystem settings.
     ./btrfsFileSystems.nix
     ./btrfsMounts.nix
@@ -51,9 +56,9 @@
 
   # Define a user account.
   # Don't forget to set a password with `passwd`.
-  users.users."yoda" = {
+  users.users."${user}" = {
     isNormalUser = true;
-    description = "Yoda";
+    description = "${user}";
     extraGroups = [ "wheel" ];
   };
 
@@ -74,7 +79,7 @@
   # Options only for build.system.vm - they won’t get applied when building build.system.toplevel aka the normal system config.
   # https://discourse.nixos.org/t/wayland-compositors-an-build-vm-not-working/46486/2
   virtualisation.vmVariant = {
-    users.users."yoda".initialPassword = "asdf";
+    users.users."${user}".initialPassword = "asdf";
     virtualisation.qemu.options = [
       "-device virtio-vga-gl"
       "-display sdl,gl=on,show-cursor=off"

modules/base-user.nix

@@ -0,0 +1,16 @@
+{ config, lib, pkgs, ... }:
+let
+  defaultUsername = "yoda";
+in
+{
+  options.yoda.user = lib.mkOption {
+    # You can find the exhaustive list of types here: https://nlewo.github.io/nixos-manual-sphinx/development/option-types.xml.html
+    type = lib.types.str;
+    default = defaultUsername;
+    description = "Username of the primary Linux user account. Must not include regex special characters.";
+  };
+
+  config = {
+    yoda.user = defaultUsername;
+  };
+}

modules/base.nix

@@ -1,4 +1,7 @@
 { config, pkgs, ... }:
+let
+  user = config.yoda.user;
+in
 {
   imports = [
     ./base-minimal.nix
@@ -14,7 +17,7 @@
 
     # Shell settings.
     ./bash.nix # bash settings.
-    ./zsh.nix # zsh as default shell for yoda and root.
+    ./zsh.nix # zsh as default shell for $user and root.
     ./fzf.nix # Fuzzy command history and file search.
 
     # nixpkgs config
@@ -32,7 +35,7 @@
   # Enable networking.
   networking.networkmanager.enable = true;
   #
-  users.users."yoda" = {
+  users.users."${user}" = {
     extraGroups = [ "networkmanager" ];
   };
 

modules/dosbox-x.nix

@@ -1,6 +1,9 @@
 { config, pkgs, ... }:
+let
+  user = config.yoda.user;
+in
 {
-  users.users."yoda" = {
+  users.users."${user}" = {
     packages = with pkgs; [
       dosbox-x # Virtual machines with DOS-based Windows such as Windows 3.x and Windows 9x
     ];

modules/file-roller.nix

@@ -1,6 +1,9 @@
 { lib, config, pkgs, ... }:
+let
+  user = config.yoda.user;
+in
 {
-  users.users."yoda" = {
+  users.users."${user}" = {
     packages = with pkgs; [
       file-roller # Archive manager: Compress and decompress
       lz4 # Add support to extract lz4 archives

modules/games.nix

@@ -1,4 +1,7 @@
 { config, pkgs, lib, ... }:
+let
+  user = config.yoda.user;
+in
 {
   # NixOS general:
   #   https://github.com/NixOS/nixpkgs/tree/nixos-23.11/pkgs/games/
@@ -42,7 +45,7 @@
     "dotnet-sdk-6.0.428"
   ];
 
-  users.users."yoda" = {
+  users.users."${user}" = {
     packages = with pkgs; [
       #
       # Sandbox

modules/gnome-terminal.nix

@@ -1,6 +1,9 @@
 { config, pkgs, ... }:
+let
+  user = config.yoda.user;
+in
 {
-  users.users."yoda" = {
+  users.users."${user}" = {
     packages = with pkgs; [
       #gnome.gnome-terminal # Terminal emulator
       nautilus-open-any-terminal # For Nautilus (GNOME files) integration
@@ -10,7 +13,7 @@
   # For Nautilus (GNOME files) integration
   programs.dconf.enable = true;
 
-  home-manager.users."yoda" = { osConfig, config, pkgs, ... }: {
+  home-manager.users."${user}" = { osConfig, config, pkgs, ... }: {
     dconf.settings = {
       # For Nautilus (GNOME files) integration
       "com/github/stunkymonkey/nautilus-open-any-terminal" = {
@@ -21,7 +24,7 @@
     programs.gnome-terminal.enable = true;
     programs.gnome-terminal.profile."74b90a31-5123-4a64-91a3-3cb31eb5cdb6" = {
       default = true;
-      visibleName = "Yoda's Terminal";
+      visibleName = "${user}'s terminal";
       font = "DejaVu Sans Mono 11";
       audibleBell = false;
 

modules/journalwatch.nix

@@ -40,12 +40,14 @@
 
 { config, pkgs, ... }:
 let
+  user = config.yoda.user;
+
   stopped-service-consumption-summary = ''
     \S+\.(service|scope|slice|swap|mount): Consumed ([0-9]+d )?([0-9]+h )?([0-9]+min )?[0-9\.]+(s|ms) CPU time(, .+)?\.'';
   sshd-log = ''
-    Accepted publickey for (root|yoda) from \S+ port \S+ ssh2: ED25519 SHA256:\S+
+    Accepted publickey for (root|${user}) from \S+ port \S+ ssh2: ED25519 SHA256:\S+
     # TODO: Change RSA key of yodaHedgehog to ED25519
-    Accepted publickey for (root|yoda) from \S+ port \S+ ssh2: RSA SHA256:\S+
+    Accepted publickey for (root|${user}) from \S+ port \S+ ssh2: RSA SHA256:\S+
     pam_unix\(sshd:session\): session opened for user \S+ by \S+
     Received disconnect from \S+ port \S+:11: disconnected by user
     Disconnected from user \S+ \S+ port \S+
@@ -61,16 +63,16 @@ let
     Invalid user \S+ from \S+ port \S+
     Disconnected from \S+ port \S+ \[preauth\]
     Disconnected from invalid user \S+ \S+ port \S+ \[preauth\]
-    Disconnected from authenticating user (root|yoda) \S+ port \S+ \[preauth\]
+    Disconnected from authenticating user (root|${user}) \S+ port \S+ \[preauth\]
     Received disconnect from \S+ port \S+:11: Client disconnecting normally \[preauth\]
     Received disconnect from \S+ port \S+:11: Bye Bye \[preauth\]
     Connection reset by invalid user \S+ \S+ port \S+ \[preauth\]
-    Connection reset by authenticating user (root|yoda) \S+ port \S+ \[preauth\]
+    Connection reset by authenticating user (root|${user}) \S+ port \S+ \[preauth\]
     Connection reset by \S+ port \S+ \[preauth\]
     Connection reset by \S+ port \S+
     Connection closed by \S+ port \S+
     Connection closed by \S+ port \S+ \[preauth\]
-    Connection closed by authenticating user (root|yoda) \S+ port \S+ \[preauth\]
+    Connection closed by authenticating user (root|${user}) \S+ port \S+ \[preauth\]
     Connection closed by invalid user \S+ \S+ port \S+ \[preauth\]
     error: kex_exchange_identification: banner line contains invalid characters
     error: kex_exchange_identification: client sent invalid protocol identifier "[^"]*"
@@ -743,7 +745,7 @@ in
           Created slice User Application Slice\.
           Queued start job for default target Main User Target\.
           pam_unix\(systemd-user:session\): session opened for user root\(uid=0\) by \(uid=0\)
-          pam_unix\(systemd-user:session\): session closed for user (root|yoda)
+          pam_unix\(systemd-user:session\): session closed for user (root|${user})
           Reload requested from client PID [0-9]+ \('systemctl'\)\.\.\.
           Reexecution requested from client PID [0-9]+ \('switch-to-confi'\)\.\.\.
           Reexecuting\.
@@ -772,7 +774,7 @@ in
           Finished loading, compiling and executing [0-9]+ rules
           #
           Registered Authentication Agent for unix-process:[0-9]+:[0-9]+ \(system bus name :[0-9\.]+ \[/run/current-system/sw/bin/pkttyagent --notify-fd 5 --fallback\], object path /org/freedesktop/PolicyKit1/AuthenticationAgent, locale en_US.UTF-8\)
-          Operator of unix-process:[0-9]+:[0-9]+ successfully authenticated as unix-user:yoda to gain ONE-SHOT authorization for action org\.freedesktop\.systemd1\.manage-units for system-bus-name::[0-9\.]+ \[systemctl start journalwatch\.service\] \(owned by unix-user:yoda\)
+          Operator of unix-process:[0-9]+:[0-9]+ successfully authenticated as unix-user:${user} to gain ONE-SHOT authorization for action org\.freedesktop\.systemd1\.manage-units for system-bus-name::[0-9\.]+ \[systemctl start journalwatch\.service\] \(owned by unix-user:${user}\)
           Unregistered Authentication Agent for unix-process:[0-9]+:[0-9]+ \(system bus name :[0-9\.]+, object path /org/freedesktop/PolicyKit1/AuthenticationAgent, locale en_US.UTF-8\) \(disconnected from bus\)
           Unregistered Authentication Agent for unix-process:unknown \(system bus name :[0-9\.]+, object path /org/freedesktop/PolicyKit1/AuthenticationAgent, locale en_US.UTF-8\) \(disconnected from bus\)
         '';
@@ -843,10 +845,10 @@ in
       }
       {
         filters = ''
-          pam_unix\(sudo:session\): session opened for user root\(uid=0\) by (yoda)?\(uid=[0-9]+\)
+          pam_unix\(sudo:session\): session opened for user root\(uid=0\) by (${user})?\(uid=[0-9]+\)
           pam_unix\(sudo:session\): session closed for user root
-          # yodaTux. If the user `yoda` runs a command with `sudo`.
+          # yodaTux. If the user `${user}` runs a command with `sudo`.
-          \s+yoda : TTY=pts/[0-9] ; PWD=/\S+ ; USER=root ; COMMAND=/.+
+          \s+${user} : TTY=pts/[0-9] ; PWD=/\S+ ; USER=root ; COMMAND=/.+
           # yodaNas. If the btrbk service is run.
           \s+btrbk : PWD=/ ; USER=root ; COMMAND=/.+
           \s+root : PWD=(/|/root) ; USER=root ; COMMAND=(/run/current-system/sw|/nix/store/[a-z0-9]+-btrfs-progs-[0-9\.]+)/bin/btrfs (subvolume list|subvolume show|subvolume delete|send|receive) .+

modules/nix-gc.nix

@@ -1,4 +1,7 @@
 { config, pkgs, ... }:
+let
+  user = config.yoda.user;
+in
 {
   # Garbage collection: Delete generations older than 5 days and then delete unreachable store objects.
 
@@ -12,7 +15,7 @@
 
   # We need to explicitly run garbage collection for user profiles,
   # this is not done by the global `nix.gc` option.
-  home-manager.users."yoda" = { osConfig, config, pkgs, ... }: {
+  home-manager.users."${user}" = { osConfig, config, pkgs, ... }: {
     nix.gc = {
       automatic = true;
       frequency = "weekly";

modules/programs-base.nix

@@ -1,4 +1,7 @@
 { config, pkgs, ... }:
+let
+  user = config.yoda.user;
+in
 {
   imports = [
     ./vlc-dvd-blu-ray.nix
@@ -6,7 +9,7 @@
     ./signal-desktop.nix
   ];
 
-  users.users."yoda" = {
+  users.users."${user}" = {
     packages = with pkgs; [
       #zenith # Terminal resource monitor / task manager
       btop   # Terminal resource monitor / task manager

modules/programs-gnome.nix

@@ -1,4 +1,7 @@
 { config, pkgs, ... }:
+let
+  user = config.yoda.user;
+in
 {
   imports = [
     ./file-roller.nix # Archive manager: Compress and decompress
@@ -7,7 +10,7 @@
     #./blackbox.nix # Terminal emulator.
   ];
 
-  users.users."yoda" = {
+  users.users."${user}" = {
     packages = with pkgs; [
       gnome-tweaks
       dconf-editor

modules/programs.nix

@@ -1,10 +1,13 @@
 { config, pkgs, ... }:
+let
+  user = config.yoda.user;
+in
 {
   imports = [
     ./thunderbird.nix # email
   ];
 
-  users.users."yoda" = {
+  users.users."${user}" = {
     packages = with pkgs; [
       #
       # CLI apps

modules/rnote.nix

@@ -1,13 +1,16 @@
 { config, pkgs, lib, ... }:
+let
+  user = config.yoda.user;
+in
 {
-  users.users."yoda" = {
+  users.users."${user}" = {
     packages = with pkgs; [
       unstable.rnote # Handwritten notes
     ];
   };
 
   programs.dconf.enable = true;
-  home-manager.users."yoda" = { osConfig, config, pkgs, lib, ... }: {
+  home-manager.users."${user}" = { osConfig, config, pkgs, lib, ... }: {
     dconf.settings = {
       "org/gnome/shell" = {
         favorite-apps = lib.mkIf (osConfig.networking.hostName == "yodaTab") ["com.github.flxzt.rnote.desktop"];

modules/syncthing.nix

@@ -1,4 +1,7 @@
 { config, pkgs, ... }:
+let
+  user = config.yoda.user;
+in
 {
   # Sync files between devices
   #
@@ -9,12 +12,12 @@
 #  services = {
 #    syncthing = {
 #      enable = true;
-#      user = "yoda";
+#      user = "${user}";
 #    };
 #  };
 
   # We run Syncthing as user service.
-  home-manager.users."yoda" = { osConfig, config, pkgs, ... }: {
+  home-manager.users."${user}" = { osConfig, config, pkgs, ... }: {
     services.syncthing = {
       enable = true;
     };

modules/thunderbird.nix

@@ -1,5 +1,7 @@
 { config, pkgs, lib, ... }:
 let
+  user = config.yoda.user;
+
   # TODO: trim whitespaces from string
   email-uni-marburg = (builtins.readFile ../secrets/email-uni-marburg);
 in
@@ -8,7 +10,7 @@ in
   # https://github.com/dr460nf1r3/dr460nixed/blob/main/home-manager/email.nix
   # https://github.com/yurrriq/dotfiles/blob/main/machines/nixps/home.nix
 
-  home-manager.users."yoda" = { osConfig, config, pkgs, ... }: {
+  home-manager.users."${user}" = { osConfig, config, pkgs, ... }: {
     accounts.email.accounts = {
       "personal" = {
         address = "daniel@systemli.org";

modules/tor-browser.nix

@@ -1,6 +1,9 @@
 { config, pkgs, lib, ... }:
+let
+  user = config.yoda.user;
+in
 {
-  users.users."yoda" = {
+  users.users."${user}" = {
     packages = with pkgs; [
       tor-browser-bundle-bin # Tor web browser.
     ];

modules/virt-manager.nix

@@ -1,11 +1,14 @@
 { config, pkgs, ... }:
+let
+  user = config.yoda.user;
+in
 {
   # See also: boxes.nix
 
   # libvirt is a dependency of Virt-manager
   # https://nixos.wiki/wiki/Libvirt
   virtualisation.libvirtd.enable = true;
-  users.users."yoda".extraGroups = [ "libvirtd" ];
+  users.users."${user}".extraGroups = [ "libvirtd" ];
 
   # Required for USB redirection to work with GNOME boxes. Maybe this is also required for virt-Manager?
   # See
@@ -18,7 +21,7 @@
   # TODO: nixpkgs virtio-win
   programs.virt-manager.enable = true;
   programs.dconf.enable = true;
-  home-manager.users."yoda" = { osConfig, config, pkgs, ... }: {
+  home-manager.users."${user}" = { osConfig, config, pkgs, ... }: {
     dconf.settings = {
       "org/virt-manager/virt-manager/connections" = {
         autoconnect = ["qemu:///system"];