restart the update provisioning session when interrupted

Author: rgl

README.md

@@ -14,7 +14,7 @@ Configure your packer template to require a [release version of the plugin](http
 packer {
   required_plugins {
     windows-update = {
-      version = "0.16.10"
+      version = "0.17.0"
       source  = "github.com/rgl/windows-update"
     }
   }

update/provisioner.go

@@ -204,12 +204,16 @@ func (p *Provisioner) update(ctx context.Context, ui packer.Ui, comm packer.Comm
 		RetryDelay: func() time.Duration { return retryableDelay },
 		Tries:      p.config.UpdateMaxRetries,
 	}.Run(ctx, func(ctx context.Context) error {
+		ui := NewUpdateUi(ui)
 		cmd := &packer.RemoteCmd{Command: elevatedCommand}
 		err := cmd.RunWithUi(ctx, comm, ui)
 		if err != nil {
 			return err
 		}
 		var exitStatus = cmd.ExitStatus()
+		if !ui.finished {
+			return fmt.Errorf("Windows update script did not finish")
+		}
 		switch exitStatus {
 		case 0:
 			return nil
@@ -380,5 +384,5 @@ func escapePowerShellString(value string) string {
 	return fmt.Sprintf(
 		"'%s'",
 		// escape single quotes with another single quote.
-		strings.Replace(value, "'", "''", -1))
+		strings.ReplaceAll(value, "'", "''"))
 }

update/update_ui.go

@@ -0,0 +1,60 @@
+package update
+
+import (
+	"io"
+	"strings"
+
+	"github.com/hashicorp/packer-plugin-sdk/packer"
+)
+
+type UpdateUi struct {
+	ui       packer.Ui
+	finished bool
+}
+
+func NewUpdateUi(ui packer.Ui) *UpdateUi {
+	return &UpdateUi{
+		ui:       ui,
+		finished: false,
+	}
+}
+
+func (u *UpdateUi) Askf(s string, args ...any) (string, error) {
+	return u.ui.Askf(s, args...)
+}
+
+func (u *UpdateUi) Ask(s string) (string, error) {
+	return u.ui.Ask(s)
+}
+
+func (u *UpdateUi) Sayf(s string, args ...any) {
+	u.ui.Sayf(s, args...)
+}
+
+func (u *UpdateUi) Say(s string) {
+	if strings.HasPrefix(s, "Exiting with code ") {
+		u.finished = true
+		return
+	}
+	u.ui.Say(s)
+}
+
+func (u *UpdateUi) Message(s string) {
+	u.Say(s)
+}
+
+func (u *UpdateUi) Errorf(s string, args ...any) {
+	u.ui.Errorf(s, args...)
+}
+
+func (u *UpdateUi) Error(s string) {
+	u.ui.Error(s)
+}
+
+func (u *UpdateUi) Machine(t string, args ...string) {
+	u.ui.Machine(t, args...)
+}
+
+func (u *UpdateUi) TrackProgress(src string, currentSize, totalSize int64, stream io.ReadCloser) (body io.ReadCloser) {
+	return u.ui.TrackProgress(src, currentSize, totalSize, stream)
+}

update/windows-update.ps1

@@ -35,6 +35,7 @@ $mock = $false
 
 function ExitWithCode($exitCode) {
     $host.SetShouldExit($exitCode)
+    Write-Output "Exiting with code $exitCode"
     Exit
 }
 
@@ -314,3 +315,5 @@ if ($updatesToInstall.Count) {
     ExitWhenRebootRequired $rebootRequired
     Write-Output 'No Windows updates found'
 }
+
+ExitWithCode 0