WIP

cmds/cmdbase/service.go

@@ -0,0 +1,185 @@
+package cmdbase
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"log/slog"
+	"os"
+	"os/exec"
+	"runtime"
+	"runtime/pprof"
+	"time"
+
+	"github.com/spf13/cobra"
+
+	"github.com/safing/portmaster/base/log"
+	"github.com/safing/portmaster/service"
+	"github.com/safing/portmaster/service/mgr"
+)
+
+var (
+	RebootOnRestart  bool
+	PrintStackOnExit bool
+)
+
+type SystemService interface {
+	Run()
+	IsService() bool
+	RestartService() error
+}
+
+type ServiceInstance interface {
+	Ready() bool
+	Start() error
+	Stop() error
+	Restart()
+	Shutdown()
+	Ctx() context.Context
+	IsShuttingDown() bool
+	ShuttingDown() <-chan struct{}
+	ShutdownCtx() context.Context
+	IsShutDown() bool
+	ShutdownComplete() <-chan struct{}
+	ExitCode() int
+	ShouldRestartIsSet() bool
+	CommandLineOperationIsSet() bool
+	CommandLineOperationExecute() error
+}
+
+var (
+	SvcFactory func(*service.ServiceConfig) (ServiceInstance, error)
+	SvcConfig  *service.ServiceConfig
+)
+
+func RunService(cmd *cobra.Command, args []string) {
+	if SvcFactory == nil || SvcConfig == nil {
+		fmt.Fprintln(os.Stderr, "internal error: service not set up in cmdbase")
+		os.Exit(1)
+	}
+
+	// Start logging.
+	// Note: Must be created before the service instance, so that they use the right logger.
+	err := log.Start(SvcConfig.LogLevel, SvcConfig.LogToStdout, SvcConfig.LogDir)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err.Error())
+		os.Exit(4)
+	}
+
+	// Create instance.
+	// Instance modules might request a cmdline execution of a function.
+	var execCmdLine bool
+	instance, err := SvcFactory(SvcConfig)
+	switch {
+	case err == nil:
+		// Continue
+	case errors.Is(err, mgr.ErrExecuteCmdLineOp):
+		execCmdLine = true
+	default:
+		fmt.Printf("error creating an instance: %s\n", err)
+		os.Exit(2)
+	}
+
+	// Execute module command line operation, if requested or available.
+	switch {
+	case !execCmdLine:
+		// Run service.
+	case !instance.CommandLineOperationIsSet():
+		fmt.Println("command line operation execution requested, but not set")
+		os.Exit(3)
+	default:
+		// Run the function and exit.
+		fmt.Println("executing cmdline op")
+		err = instance.CommandLineOperationExecute()
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "command line operation failed: %s\n", err)
+			os.Exit(3)
+		}
+		os.Exit(0)
+	}
+
+	// START
+
+	// Create system service.
+	service := NewSystemService(instance)
+
+	// Start instance via system service manager.
+	go func() {
+		service.Run()
+	}()
+
+	// SHUTDOWN
+
+	// Wait for shutdown to be started.
+	<-instance.ShuttingDown()
+
+	// Wait for shutdown to be finished.
+	select {
+	case <-instance.ShutdownComplete():
+		// Print stack on shutdown, if enabled.
+		if PrintStackOnExit {
+			printStackTo(log.GlobalWriter, "PRINTING STACK ON EXIT")
+		}
+	case <-time.After(3 * time.Minute):
+		printStackTo(log.GlobalWriter, "PRINTING STACK - TAKING TOO LONG FOR SHUTDOWN")
+	}
+
+	// Check if restart was triggered and send start service command if true.
+	if instance.ShouldRestartIsSet() && service.IsService() {
+		// Check if we should reboot instead.
+		var rebooting bool
+		if RebootOnRestart {
+			// Trigger system reboot and record success.
+			rebooting = triggerSystemReboot()
+			if !rebooting {
+				log.Warningf("updates: rebooting failed, only restarting service instead")
+			}
+		}
+
+		// Restart service if not rebooting.
+		if !rebooting {
+			if err := service.RestartService(); err != nil {
+				slog.Error("failed to restart service", "err", err)
+			}
+		}
+	}
+
+	// Stop logging.
+	log.Shutdown()
+
+	// Give a small amount of time for everything to settle:
+	// - All logs written.
+	// - Restart command started, if needed.
+	// - Windows service manager notified.
+	time.Sleep(100 * time.Millisecond)
+
+	// Exit
+	os.Exit(instance.ExitCode())
+}
+
+func printStackTo(writer io.Writer, msg string) {
+	_, err := fmt.Fprintf(writer, "===== %s =====\n", msg)
+	if err == nil {
+		err = pprof.Lookup("goroutine").WriteTo(writer, 1)
+	}
+	if err != nil {
+		slog.Error("failed to write stack trace", "err", err)
+	}
+}
+
+func triggerSystemReboot() (success bool) {
+	switch runtime.GOOS {
+	case "linux":
+		err := exec.Command("systemctl", "reboot").Run()
+		if err != nil {
+			log.Errorf("updates: triggering reboot with systemctl failed: %s", err)
+			return false
+		}
+	default:
+		log.Warningf("updates: rebooting is not support on %s", runtime.GOOS)
+		return false
+	}
+
+	return true
+}