Register the desktop app path with launch services

ee/allowedcmd/cmd_darwin.go

@@ -67,6 +67,10 @@ func Lsof(ctx context.Context, arg ...string) (*exec.Cmd, error) {
 	return validatedCommand(ctx, "/usr/sbin/lsof", arg...)
 }
 
+func Lsregister(ctx context.Context, arg ...string) (*exec.Cmd, error) {
+	return validatedCommand(ctx, "/System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/LaunchServices.framework/Versions/A/Support/lsregister", arg...)
+}
+
 func Mdfind(ctx context.Context, arg ...string) (*exec.Cmd, error) {
 	return validatedCommand(ctx, "/usr/bin/mdfind", arg...)
 }

ee/desktop/user/universallink/handler_darwin.go

@@ -9,10 +9,12 @@ import (
 	"log/slog"
 	"net/http"
 	"net/url"
+	"os"
 	"strings"
 	"sync"
 	"time"
 
+	"github.com/kolide/launcher/ee/allowedcmd"
 	"github.com/kolide/launcher/ee/gowrapper"
 	"github.com/kolide/launcher/ee/localserver"
 )
@@ -41,6 +43,13 @@ func NewUniversalLinkHandler(slogger *slog.Logger) (*universalLinkHandler, chan
 }
 
 func (u *universalLinkHandler) Execute() error {
+	// Register self
+	if err := register(); err != nil {
+		u.slogger.Log(context.TODO(), slog.LevelWarn,
+			"could not register desktop app with Launch Services on startup",
+			"err", err,
+		)
+	}
 	for {
 		select {
 		case i := <-u.urlInput:
@@ -74,6 +83,36 @@ func (u *universalLinkHandler) Interrupt(_ error) {
 	close(u.urlInput)
 }
 
+func register() error {
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	currentExecutable, err := os.Executable()
+	if err != nil {
+		return fmt.Errorf("getting current executable: %w", err)
+	}
+
+	// If we're running the originally-installed version of launcher, no need to register
+	if strings.HasPrefix(currentExecutable, "/usr/local") {
+		return nil
+	}
+
+	// Point to `Kolide.app`
+	currentExecutable = strings.TrimSuffix(currentExecutable, "/Contents/MacOS/launcher")
+
+	// Run lsregister against this path
+	lsregisterCmd, err := allowedcmd.Lsregister(ctx, currentExecutable)
+	if err != nil {
+		return fmt.Errorf("creating lsregister %s command: %w", currentExecutable, err)
+	}
+
+	if out, err := lsregisterCmd.CombinedOutput(); err != nil {
+		return fmt.Errorf("running lsregister %s: output `%s`, err: %w", currentExecutable, string(out), err)
+	}
+
+	return nil
+}
+
 // handleUniversalLinkRequest receives requests, validates them, and forwards them
 // to launcher root's localserver.
 func (u *universalLinkHandler) handleUniversalLinkRequest(requestUrl string) error {