Fix marker publish verification when bucket is private

We need to use the private link for verification otherwise it will
simply not work. This patch also adds more verbosity around the update
process to enhance debugging.

Related to kubernetes/kubernetes#127350

Signed-off-by: Sascha Grunert <[email protected]>

pkg/release/publish.go

@@ -360,6 +360,7 @@ func (p *Publisher) PublishToGcs(
 		return fmt.Errorf("write latest version file: %w", err)
 	}
 
+	logrus.Infof("Running `gsutil cp` from %s to: %s", latestFile, publishFileDst)
 	if err := p.client.GSUtil(
 		"-m",
 		"-h", "Content-Type:text/plain",
@@ -374,20 +375,22 @@ func (p *Publisher) PublishToGcs(
 	var content string
 	if !privateBucket {
 		// If public, validate public link
+		logrus.Infof("Validating uploaded version file using HTTP at %s", publicLink)
 		response, err := p.client.GetURLResponse(publicLink)
 		if err != nil {
 			return fmt.Errorf("get content of %s: %w", publicLink, err)
 		}
 		content = response
 	} else {
-		response, err := p.client.GSUtilOutput("cat", publicLink)
+		// Use the private location
+		logrus.Infof("Validating uploaded version file using `gsutil cat` at %s", publishFileDst)
+		response, err := p.client.GSUtilOutput("cat", publishFileDst)
 		if err != nil {
-			return fmt.Errorf("get content of %s: %w", publicLink, err)
+			return fmt.Errorf("get content of %s: %w", publishFileDst, err)
 		}
 		content = response
 	}
 
-	logrus.Infof("Validating uploaded version file at %s", publicLink)
 	if version != content {
 		return fmt.Errorf(
 			"version %s it not equal response %s",