karabiner-elements: init module

2 files changed, 116 insertions, 0 deletions

diff --git a/modules/module-list.nix b/modules/module-list.nix
index 57b0bf8..95a270e 100644
--- a/modules/module-list.nix
+++ b/modules/module-list.nix
@@ -47,6 +47,7 @@
   ./services/dnsmasq.nix
   ./services/emacs.nix
   ./services/gitlab-runner.nix
+  ./services/karabiner-elements
   ./services/khd
   ./services/kwm
   ./services/lorri.nix
diff --git a/modules/services/karabiner-elements/default.nix b/modules/services/karabiner-elements/default.nix
new file mode 100644
index 0000000..4cdba2d
--- /dev/null
+++ b/modules/services/karabiner-elements/default.nix
@@ -0,0 +1,115 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  cfg = config.services.karabiner-elements;
+
+  parentAppDir = "/Applications/.Nix-Karabiner";
+in
+
+{
+  options = {
+    services.karabiner-elements.enable = mkEnableOption "Karabiner-Elements";
+  };
+
+  config = mkIf cfg.enable {
+    environment.systemPackages = [ pkgs.karabiner-elements ];
+
+    system.activationScripts.extraActivation.text = ''
+      rm -rf ${parentAppDir}
+      mkdir -p ${parentAppDir}
+      # Kernel extensions must reside inside of /Applications, they cannot be symlinks
+      cp -r ${pkgs.karabiner-elements.driver}/Applications/.Karabiner-VirtualHIDDevice-Manager.app ${parentAppDir}
+    '';
+
+    # We need the karabiner_grabber and karabiner_observer daemons to run after the
+    # Nix Store has been mounted, but we can't use wait4path as they need to be
+    # executed directly for the Input Monitoring permission. We also want these
+    # daemons to auto restart but if they start up without the Nix Store they will
+    # refuse to run again until they've been unloaded and loaded back in so we can
+    # use a helper daemon to start them.
+    launchd.daemons.start_karabiner_daemons = {
+      script = ''
+        /bin/wait4path ${pkgs.karabiner-elements}
+        launchctl kickstart system/org.pqrs.karabiner.karabiner_grabber
+        launchctl kickstart system/org.pqrs.karabiner.karabiner_observer
+      '';
+      # Due to the daemons being loaded in alphabetical order during darwin-rebuild switch
+      # we need to set the label so that this daemon will be loaded after karabiner_grabber
+      # and karabiner_observer so that no reboot is required to start these daemons.
+      serviceConfig.Label = "org.xyz.start_karabiner_daemons";
+      serviceConfig.RunAtLoad = true;
+    };
+
+    launchd.daemons.karabiner_grabber = {
+      serviceConfig.ProgramArguments = [
+        "${pkgs.karabiner-elements}/Library/Application Support/org.pqrs/Karabiner-Elements/bin/karabiner_grabber"
+      ];
+      serviceConfig.ProcessType = "Interactive";
+      serviceConfig.Label = "org.pqrs.karabiner.karabiner_grabber";
+      serviceConfig.KeepAlive.SuccessfulExit = true;
+      serviceConfig.KeepAlive.Crashed = true;
+      serviceConfig.KeepAlive.AfterInitialDemand = true;
+    };
+
+    launchd.daemons.karabiner_observer = {
+      serviceConfig.ProgramArguments = [
+        "${pkgs.karabiner-elements}/Library/Application Support/org.pqrs/Karabiner-Elements/bin/karabiner_observer"
+      ];
+
+      serviceConfig.Label = "org.pqrs.karabiner.karabiner_observer";
+      serviceConfig.KeepAlive.SuccessfulExit = true;
+      serviceConfig.KeepAlive.Crashed = true;
+      serviceConfig.KeepAlive.AfterInitialDemand = true;
+    };
+
+    launchd.daemons.Karabiner-DriverKit-VirtualHIDDeviceClient = {
+      serviceConfig.ProgramArguments = [
+        "/bin/sh" "-c"
+        # For unknown reasons this daemon will fail if VirtualHIDDeviceClient is not exec'd.
+        "/bin/wait4path ${pkgs.karabiner-elements.driver} && exec \"${pkgs.karabiner-elements.driver}/Library/Application Support/org.pqrs/Karabiner-DriverKit-VirtualHIDDevice/Applications/Karabiner-DriverKit-VirtualHIDDeviceClient.app/Contents/MacOS/Karabiner-DriverKit-VirtualHIDDeviceClient\""
+      ];
+      serviceConfig.ProcessType = "Interactive";
+      serviceConfig.Label = "org.pqrs.Karabiner-DriverKit-VirtualHIDDeviceClient";
+      serviceConfig.KeepAlive = true;
+    };
+
+    # Normally karabiner_console_user_server calls activate on the manager but
+    # because we use a custom location we need to call activate manually.
+    launchd.user.agents.activate_karabiner_system_ext = {
+      serviceConfig.ProgramArguments = [
+        "${parentAppDir}/.Karabiner-VirtualHIDDevice-Manager.app/Contents/MacOS/Karabiner-VirtualHIDDevice-Manager" "activate"
+      ];
+      serviceConfig.RunAtLoad = true;
+    };
+
+    # We can't put this inside the extraActivation script as /run gets nuked
+    # every reboot and the extraActivation script only gets run on darwin-rebuild
+    # switch.
+    launchd.daemons.setsuid_karabiner_session_monitor = {
+      script = ''
+        set -e
+        /bin/wait4path ${pkgs.karabiner-elements}
+        rm -rf /run/wrappers
+        mkdir -p /run/wrappers/bin
+        install -m4555 "${pkgs.karabiner-elements}/Library/Application Support/org.pqrs/Karabiner-Elements/bin/karabiner_session_monitor" /run/wrappers/bin
+      '';
+      serviceConfig.RunAtLoad = true;
+      serviceConfig.KeepAlive.SuccessfulExit = false;
+    };
+
+    launchd.user.agents.karabiner_session_monitor = {
+      serviceConfig.ProgramArguments = [
+        "/bin/sh" "-c"
+        "/bin/wait4path /run/wrappers/bin && /run/wrappers/bin/karabiner_session_monitor"
+      ];
+      serviceConfig.Label = "org.pqrs.karabiner.karabiner_session_monitor";
+      serviceConfig.KeepAlive = true;
+    };
+
+    environment.userLaunchAgents."org.pqrs.karabiner.agent.karabiner_grabber.plist".source = "${pkgs.karabiner-elements}/Library/LaunchAgents/org.pqrs.karabiner.agent.karabiner_grabber.plist";
+    environment.userLaunchAgents."org.pqrs.karabiner.agent.karabiner_observer.plist".source = "${pkgs.karabiner-elements}/Library/LaunchAgents/org.pqrs.karabiner.agent.karabiner_observer.plist";
+    environment.userLaunchAgents."org.pqrs.karabiner.karabiner_console_user_server.plist".source = "${pkgs.karabiner-elements}/Library/LaunchAgents/org.pqrs.karabiner.karabiner_console_user_server.plist";
+  };
+}