Allow upstream systemd units to be extended

If you define a unit, and either systemd or a package in
systemd.packages already provides that unit, then we now generate a
file /etc/systemd/system/<unit>.d/overrides.conf. This makes it
possible to use upstream units, while allowing them to be customised
from the NixOS configuration. For instance, the module nix-daemon.nix
now uses the units provided by the Nix package. And all unit
definitions that duplicated upstream systemd units are finally gone.

This makes the baseUnit option unnecessary, so I've removed it.

1 files changed, 3 insertions, 6 deletions

diff --git a/nixos/modules/services/ttys/agetty.nix b/nixos/modules/services/ttys/agetty.nix
index c4571ef856f4..df21ebbd9743 100644
--- a/nixos/modules/services/ttys/agetty.nix
+++ b/nixos/modules/services/ttys/agetty.nix
@@ -49,22 +49,19 @@ with lib;
   config = {
 
     systemd.services."getty@" =
-      { baseUnit = "${config.systemd.package}/example/systemd/system/getty@.service";
-        serviceConfig.ExecStart = "@${pkgs.utillinux}/sbin/agetty agetty --noclear --login-program ${pkgs.shadow}/bin/login --keep-baud %I 115200,38400,9600 $TERM";
+      { serviceConfig.ExecStart = "@${pkgs.utillinux}/sbin/agetty agetty --noclear --login-program ${pkgs.shadow}/bin/login --keep-baud %I 115200,38400,9600 $TERM";
         restartIfChanged = false;
       };
 
     systemd.services."serial-getty@" =
-      { baseUnit = "${config.systemd.package}/example/systemd/system/serial-getty@.service";
-        serviceConfig.ExecStart =
+      { serviceConfig.ExecStart =
           let speeds = concatStringsSep "," (map toString config.services.mingetty.serialSpeed);
           in "@${pkgs.utillinux}/sbin/agetty agetty --login-program ${pkgs.shadow}/bin/login %I ${speeds} $TERM";
         restartIfChanged = false;
       };
 
     systemd.services."container-getty@" =
-      { baseUnit = "${config.systemd.package}/example/systemd/system/container-getty@.service";
-        unitConfig.ConditionPathExists = "/dev/pts/%I"; # Work around being respawned when "machinectl login" exits.
+      { unitConfig.ConditionPathExists = "/dev/pts/%I"; # Work around being respawned when "machinectl login" exits.
         serviceConfig.ExecStart = "@${pkgs.utillinux}/sbin/agetty agetty --noclear --login-program ${pkgs.shadow}/bin/login --keep-baud pts/%I 115200,38400,9600 $TERM";
         restartIfChanged = false;
       };