1 files changed, 126 insertions, 0 deletions

diff --git a/modules/agetty.nix b/modules/agetty.nix
new file mode 100644
index 0000000..88fd82e
--- /dev/null
+++ b/modules/agetty.nix
@@ -0,0 +1,126 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+
+  autologinArg = optionalString (config.services.agetty.autologinUser != null) "--autologin ${config.services.agetty.autologinUser}";
+  defaultUserArg = optionalString (config.services.agetty.defaultUser != null) "-n --login-options ${config.services.agetty.defaultUser}";
+  gettyCmd = extraArgs: "@${pkgs.utillinux}/sbin/agetty agetty --login-program ${pkgs.shadow}/bin/login ${autologinArg} ${defaultUserArg} ${extraArgs}";
+
+in
+
+{
+
+  ###### interface
+
+  options = {
+
+    services.agetty = {
+
+      autologinUser = mkOption {
+        type = types.nullOr types.str;
+        default = null;
+        description = ''
+          Username of the account that will be automatically logged in at the console.
+          If unspecified, a login prompt is shown as usual.
+        '';
+      };
+
+      defaultUser = mkOption {
+        type = types.nullOr types.str;
+        default = null;
+        description = ''
+          If set this will prompt only for password for given user (instead of login+password)
+        '';
+      };
+
+      greetingLine = mkOption {
+        type = types.str;
+        description = ''
+          Welcome line printed by agetty.
+          The default shows current NixOS version label, machine type and tty.
+        '';
+      };
+
+      helpLine = mkOption {
+        type = types.lines;
+        default = "";
+        description = ''
+          Help line printed by agetty below the welcome line.
+          Used by the installation CD to give some hints on
+          how to proceed.
+        '';
+      };
+
+      serialSpeed = mkOption {
+        type = types.listOf types.int;
+        default = [ 115200 57600 38400 9600 ];
+        example = [ 38400 9600 ];
+        description = ''
+            Bitrates to allow for agetty's listening on serial ports. Listing more
+            bitrates gives more interoperability but at the cost of long delays
+            for getting a sync on the line.
+        '';
+      };
+
+    };
+
+  };
+
+
+  ###### implementation
+
+  config = {
+    # Note: this is set here rather than up there so that changing
+    # nixos.label would not rebuild manual pages
+    services.agetty.greetingLine = mkDefault ''<<< Welcome to NixOS ${config.system.nixos.label} (\m) - \l >>>'';
+
+    systemd.services."getty@" =
+      { serviceConfig.ExecStart = [
+          "" # override upstream default with an empty ExecStart
+          (gettyCmd "--noclear --keep-baud %I 115200,38400,9600 $TERM")
+        ];
+        restartIfChanged = false;
+      };
+
+    systemd.services."serial-getty@" =
+      let speeds = concatStringsSep "," (map toString config.services.agetty.serialSpeed); in
+      { serviceConfig.ExecStart = [
+          "" # override upstream default with an empty ExecStart
+          (gettyCmd "%I ${speeds} $TERM")
+        ];
+        restartIfChanged = false;
+      };
+
+    systemd.services."container-getty@" =
+      { serviceConfig.ExecStart = [
+          "" # override upstream default with an empty ExecStart
+          (gettyCmd "--noclear --keep-baud pts/%I 115200,38400,9600 $TERM")
+        ];
+        restartIfChanged = false;
+      };
+
+    systemd.services.console-getty =
+      { serviceConfig.ExecStart = [
+          "" # override upstream default with an empty ExecStart
+          (gettyCmd "--noclear --keep-baud console 115200,38400,9600 $TERM")
+        ];
+        serviceConfig.Restart = "always";
+        restartIfChanged = false;
+        enable = mkDefault config.boot.isContainer;
+      };
+
+    # environment.etc.issue =
+    #   { # Friendly greeting on the virtual consoles.
+    #     source = pkgs.writeText "issue" ''
+
+    #       ${config.services.agetty.greetingLine}
+    #       ${config.services.agetty.helpLine}
+
+    #     '';
+    #   };
+
+  };
+
+}