cmd/storagenode: use the right subcommand for restarting windows services

Commit 3cf89633e9 is changed how the cobra subcommands are created for storagenode (with prefering local variables instead of package level variables).

However, there is a bug which makes it impossible to restart Storagenode services on Windows: the refactored code creates the rootCmd/runCmd twice: therefore the ctx of the running process is not exactly the same as the ctx which supposed to be stopped / cancelled.

This patch fixes this problem with re-using exising, initialized command instead of creating a new one for cancellation.

Fixes: https://github.com/storj/storj/issues/5845

Change-Id: Ib8a4b80d4574e448f65c8558e927c0908c9c5eed

cmd/storagenode/main.go

@@ -16,13 +16,13 @@ import (
 func main() {
 	process.SetHardcodedApplicationName("storagenode")
 
-	if startAsService() {
-		return
-	}
-
 	allowDefaults := !isFilewalkerCommand()
 	rootCmd, _ := newRootCmd(allowDefaults)
 
+	if startAsService(rootCmd) {
+		return
+	}
+
 	loggerFunc := func(logger *zap.Logger) *zap.Logger {
 		return logger.With(zap.String("process", rootCmd.Use))
 	}

cmd/storagenode/service_nonwindows.go

@@ -6,6 +6,8 @@
 
 package main
 
-func startAsService() bool {
+import "github.com/spf13/cobra"
+
+func startAsService(*cobra.Command) bool {
 	return false
 }

cmd/storagenode/service_windows.go

@@ -23,9 +23,7 @@ import (
 	"storj.io/private/process"
 )
 
-var rootCmd, runCmd *cobra.Command
-
-func startAsService() bool {
+func startAsService(cmd *cobra.Command) bool {
 	isService, err := svc.IsWindowsService()
 	if err != nil {
 		zap.L().Fatal("Failed to determine if session is a service.", zap.Error(err))
@@ -43,12 +41,10 @@ func startAsService() bool {
 		return false
 	}
 
-	var factory *Factory
-	rootCmd, factory = newRootCmd(true)
-	runCmd = newRunCmd(factory)
-
 	// Initialize the Windows Service handler
-	err = svc.Run("storagenode", &service{})
+	err = svc.Run("storagenode", &service{
+		rootCmd: cmd,
+	})
 	if err != nil {
 		zap.L().Fatal("Service failed.", zap.Error(err))
 	}
@@ -56,16 +52,29 @@ func startAsService() bool {
 	return true
 }
 
-type service struct{}
+type service struct {
+	rootCmd *cobra.Command
+}
 
 func (m *service) Execute(args []string, r <-chan svc.ChangeRequest, changes chan<- svc.Status) (ssec bool, errno uint32) {
 	const cmdsAccepted = svc.AcceptStop | svc.AcceptShutdown
 
+	var runCmd *cobra.Command
+	for _, c := range m.rootCmd.Commands() {
+		if c.Use == "run" {
+			runCmd = c
+		}
+	}
+
+	if runCmd == nil {
+		panic("Assertion is failed: 'run' sub-command is not found.")
+	}
+
 	changes <- svc.Status{State: svc.StartPending}
 
 	var group errgroup.Group
 	group.Go(func() error {
-		process.Exec(rootCmd)
+		process.Exec(m.rootCmd)
 		return nil
 	})
 	defer func() { _ = group.Wait() }()