feat!: add linux cross-platform support with systemd unit file

internal/service/linux.go

@@ -0,0 +1,90 @@
+//go:build linux
+
+package service
+
+import (
+	"log/slog"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+
+	"ha-tray/internal/app"
+
+	"github.com/coreos/go-systemd/daemon"
+)
+
+const serviceName = "HATray"
+
+// linuxService implements the Service interface for Linux
+// It integrates with systemd and controls the app layer
+// according to systemd signals (start, stop, reload)
+type linuxService struct {
+	logger *slog.Logger
+	app    *app.App
+}
+
+// NewService creates a new Linux service instance
+func NewService(logger *slog.Logger) Service {
+	return &linuxService{
+		logger: logger,
+		app:    app.NewApp(logger),
+	}
+}
+
+// Run implements the Service interface for Linux
+func (s *linuxService) Run() error {
+	s.logger.Info("starting service")
+
+	// Notify systemd that we are starting
+	daemon.SdNotify(false, "STATUS=Starting HATray...\n")
+
+	// Setup signal handling for systemd
+	sigs := make(chan os.Signal, 1)
+	signal.Notify(sigs, syscall.SIGINT, syscall.SIGTERM, syscall.SIGHUP, syscall.SIGUSR1, syscall.SIGUSR2)
+	done := make(chan struct{})
+
+	// Notify systemd that we are ready
+	daemon.SdNotify(false, "READY=1")
+	daemon.SdNotify(false, "STATUS=HATray running\n")
+
+	go func() {
+		for {
+			sig := <-sigs
+			s.logger.Info("signal received", "signal", sig)
+			switch sig {
+			case syscall.SIGINT, syscall.SIGTERM:
+				daemon.SdNotify(false, "STOPPING=1")
+				s.logger.Info("stopping service")
+				s.app.Stop()
+				close(done)
+				return
+			case syscall.SIGHUP:
+				s.logger.Info("reloading service")
+				daemon.SdNotify(false, "RELOADING=1")
+				s.app.Reload()
+				daemon.SdNotify(false, "READY=1")
+			case syscall.SIGUSR1:
+				s.logger.Info("pausing service")
+				s.app.Pause()
+			case syscall.SIGUSR2:
+				s.logger.Info("resuming service")
+				s.app.Resume()
+			}
+		}
+	}()
+
+	// Main loop: heartbeat to systemd
+	ticker := time.NewTicker(30 * time.Second)
+	defer ticker.Stop()
+	for {
+		select {
+		case <-done:
+			s.logger.Info("service stopped")
+			return nil
+		case <-ticker.C:
+			daemon.SdNotify(false, "WATCHDOG=1")
+			s.logger.Debug("heartbeat")
+		}
+	}
+}