modules/logind: add option to disable logind

1 files changed, 121 insertions, 0 deletions

diff --git a/modules/logind.nix b/modules/logind.nix
new file mode 100644
index 0000000..5e6dcdf
--- /dev/null
+++ b/modules/logind.nix
@@ -0,0 +1,121 @@
+{ config, lib, ... }:
+
+let
+  cfg = config.services.logind;
+  inherit (lib) mkOption types;
+
+  logindHandlerType = types.enum [
+    "ignore" "poweroff" "reboot" "halt" "kexec" "suspend"
+    "hibernate" "hybrid-sleep" "suspend-then-hibernate" "lock"
+  ];
+in
+{
+  options.services.logind = {
+    enable = mkOption {
+      default = true;
+      description = "Whether to enable logind.";
+      type = types.bool;
+    };
+
+    extraConfig = mkOption {
+      default = "";
+      type = types.lines;
+      example = "IdleAction=lock";
+      description = lib.mdDoc ''
+        Extra config options for systemd-logind. See
+        [
+        logind.conf(5)](https://www.freedesktop.org/software/systemd/man/logind.conf.html) for available options.
+      '';
+    };
+
+    killUserProcesses = mkOption {
+      default = false;
+      type = types.bool;
+      description = lib.mdDoc ''
+        Specifies whether the processes of a user should be killed
+        when the user logs out.  If true, the scope unit corresponding
+        to the session and all processes inside that scope will be
+        terminated.  If false, the scope is "abandoned" (see
+        [systemd.scope(5)](https://www.freedesktop.org/software/systemd/man/systemd.scope.html#)), and processes are not killed.
+
+        See [logind.conf(5)](https://www.freedesktop.org/software/systemd/man/logind.conf.html#KillUserProcesses=)
+        for more details.
+      '';
+    };
+
+    lidSwitch = mkOption {
+      default = "suspend";
+      example = "ignore";
+      type = logindHandlerType;
+
+      description = lib.mdDoc ''
+        Specifies what to be done when the laptop lid is closed.
+      '';
+    };
+
+    lidSwitchDocked = mkOption {
+      default = "ignore";
+      example = "suspend";
+      type = logindHandlerType;
+
+      description = lib.mdDoc ''
+        Specifies what to be done when the laptop lid is closed
+        and another screen is added.
+      '';
+    };
+
+    lidSwitchExternalPower = mkOption {
+      default = cfg.lidSwitch;
+      defaultText = lib.literalExpression "services.logind.lidSwitch";
+      example = "ignore";
+      type = logindHandlerType;
+
+      description = lib.mdDoc ''
+        Specifies what to do when the laptop lid is closed and the system is
+        on external power. By default use the same action as specified in
+        services.logind.lidSwitch.
+      '';
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    systemd.additionalUpstreamSystemUnits = [
+      "systemd-logind.service"
+      "autovt@.service"
+      "systemd-user-sessions.service"
+    ] ++ lib.optionals config.systemd.package.withImportd [
+      "dbus-org.freedesktop.import1.service"
+    ] ++ lib.optionals config.systemd.package.withMachined [
+      "dbus-org.freedesktop.machine1.service"
+    ] ++ lib.optionals config.systemd.package.withPortabled [
+      "dbus-org.freedesktop.portable1.service"
+    ] ++ [
+      "dbus-org.freedesktop.login1.service"
+      "user@.service"
+      "user-runtime-dir@.service"
+    ];
+
+    environment.etc = {
+      "systemd/logind.conf".text = ''
+        [Login]
+        KillUserProcesses=${if cfg.killUserProcesses then "yes" else "no"}
+        HandleLidSwitch=${cfg.lidSwitch}
+        HandleLidSwitchDocked=${cfg.lidSwitchDocked}
+        HandleLidSwitchExternalPower=${cfg.lidSwitchExternalPower}
+        ${cfg.extraConfig}
+      '';
+    };
+
+    # Restarting systemd-logind breaks X11
+    # - upstream commit: https://cgit.freedesktop.org/xorg/xserver/commit/?id=dc48bd653c7e101
+    # - systemd announcement: https://github.com/systemd/systemd/blob/22043e4317ecd2bc7834b48a6d364de76bb26d91/NEWS#L103-L112
+    # - this might be addressed in the future by xorg
+    #systemd.services.systemd-logind.restartTriggers = [ config.environment.etc."systemd/logind.conf".source ];
+    systemd.services.systemd-logind.restartIfChanged = false;
+    systemd.services.systemd-logind.stopIfChanged = false;
+
+    # The user-runtime-dir@ service is managed by systemd-logind we should not touch it or else we break the users' sessions.
+    systemd.services."user-runtime-dir@".stopIfChanged = false;
+    systemd.services."user-runtime-dir@".restartIfChanged = false;
+  };
+}