Add windows service install/uninstall, improve service handling

pmctl/service_windows.go

@@ -1,11 +1,17 @@
 package main
 
+// Based on the offical Go examples from
+// https://github.com/golang/sys/blob/master/windows/svc/example
+// by The Go Authors.
+// Original LICENSE (sha256sum: 2d36597f7117c38b006835ae7f537487207d8ec407aa9d9980794b2030cbc067) can be found in vendor/pkg cache directory.
+
 import (
 	"fmt"
 	"time"
 
 	"github.com/spf13/cobra"
 	"golang.org/x/sys/windows/svc"
+	"golang.org/x/sys/windows/svc/debug"
 	"golang.org/x/sys/windows/svc/eventlog"
 )
 
@@ -29,6 +35,9 @@ var (
 	// helpers for execution
 	runError   chan error
 	runWrapper func() error
+
+	// eventlog
+	eventlogger *eventlog.Log
 )
 
 func init() {
@@ -50,10 +59,10 @@ func (ws *windowsService) Execute(args []string, changeRequests <-chan svc.Chang
 	}()
 
 	// poll for start completion
-	var started chan struct{}
+	started := make(chan struct{})
 	go func() {
 		for {
-			time.Sleep(100 * time.Millisecond)
+			time.Sleep(10 * time.Millisecond)
 			if childIsRunning.IsSet() {
 				close(started)
 				return
@@ -66,39 +75,41 @@ func (ws *windowsService) Execute(args []string, changeRequests <-chan svc.Chang
 	case err := <-runError:
 		// TODO: log error to windows
 		fmt.Printf("%s start error: %s", logPrefix, err)
+		eventlogger.Error(4, fmt.Sprintf("failed to start Portmaster Core: %s", err))
+		changes <- svc.Status{State: svc.Stopped}
 		return false, 1
 	case <-started:
 		// give some more time for enabling packet interception
 		time.Sleep(500 * time.Millisecond)
 		changes <- svc.Status{State: svc.Running, Accepts: cmdsAccepted}
-		fmt.Printf("%s startup complete, entered service running state", logPrefix)
+		fmt.Printf("%s startup complete, entered service running state\n", logPrefix)
 	}
 
 	// wait for change requests
+serviceLoop:
 	for {
 		select {
 		case <-shuttingDown:
-			// signal that we are shutting down
-			changes <- svc.Status{State: svc.StopPending}
-			// wait for program to exit
-			<-programEnded
-			return
+			break serviceLoop
 		case c := <-changeRequests:
 			switch c.Cmd {
 			case svc.Interrogate:
 				changes <- c.CurrentStatus
 			case svc.Stop, svc.Shutdown:
-				changes <- svc.Status{State: svc.StopPending}
 				initiateShutdown()
-				// wait for program to exit
-				<-programEnded
-				return
+				break serviceLoop
 			default:
-				fmt.Printf("%s unexpected control request: #%d", logPrefix, c)
+				fmt.Printf("%s unexpected control request: #%d\n", logPrefix, c)
 			}
 		}
 	}
+
+	// signal that we are shutting down
 	changes <- svc.Status{State: svc.StopPending}
+	// wait for program to exit
+	<-programEnded
+	// signal shutdown complete
+	changes <- svc.Status{State: svc.Stopped}
 	return
 }
 
@@ -108,6 +119,12 @@ func runService(cmd *cobra.Command, opts *Options) error {
 		return run(cmd, opts)
 	}
 
+	// check if we are running interactively
+	isDebug, err := svc.IsAnInteractiveSession()
+	if err != nil {
+		return fmt.Errorf("could not determine if running interactively: %s", err)
+	}
+
 	// open eventlog
 	// TODO: do something useful with eventlog
 	elog, err := eventlog.Open(serviceName)
@@ -115,9 +132,17 @@ func runService(cmd *cobra.Command, opts *Options) error {
 		return fmt.Errorf("failed to open eventlog: %s", err)
 	}
 	defer elog.Close()
+	eventlogger = elog
 	elog.Info(1, fmt.Sprintf("starting %s service", serviceName))
 
-	err = svc.Run(serviceName, &windowsService{})
+	// select run method bas
+	run := svc.Run
+	if isDebug {
+		fmt.Printf("%s WARNING: running interactively, switching to debug execution (no real service).\n", logPrefix)
+		run = debug.Run
+	}
+	// run
+	err = run(serviceName, &windowsService{})
 	if err != nil {
 		elog.Error(3, fmt.Sprintf("%s service failed: %v", serviceName, err))
 		return fmt.Errorf("failed to start service: %s", err)