[content-service] Fix: emit fromBackup stats

Tool: gitpod/catfood.gitpod.cloud

Author: geropl

components/content-service/pkg/initializer/initializer.go

@@ -468,20 +468,38 @@ func InitializeWorkspace(ctx context.Context, location string, remoteStorage sto
 		}
 	}
 
-	// Run the initializer
+	// Try to download a backup first
+	initialSize, fsErr := getFsUsage()
+	if fsErr != nil {
+		log.WithError(fsErr).Error("could not get disk usage")
+	}
+	downloadStart := time.Now()
 	hasBackup, err := remoteStorage.Download(ctx, location, storage.DefaultBackup, cfg.mappings)
 	if err != nil {
 		return src, nil, xerrors.Errorf("cannot restore backup: %w", err)
 	}
+	downloadDuration := time.Since(downloadStart)
 
 	span.SetTag("hasBackup", hasBackup)
 	if hasBackup {
 		src = csapi.WorkspaceInitFromBackup
-	} else {
-		src, stats, err = cfg.Initializer.Run(ctx, cfg.mappings)
-		if err != nil {
-			return src, nil, xerrors.Errorf("cannot initialize workspace: %w", err)
+
+		currentSize, fsErr := getFsUsage()
+		if fsErr != nil {
+			log.WithError(fsErr).Error("could not get disk usage")
 		}
+		stats = []csapi.InitializerMetric{{
+			Type:     "fromBackup",
+			Duration: downloadDuration,
+			Size:     currentSize - initialSize,
+		}}
+		return
+	}
+
+	// If there is not backup, run the initializer
+	src, stats, err = cfg.Initializer.Run(ctx, cfg.mappings)
+	if err != nil {
+		return src, nil, xerrors.Errorf("cannot initialize workspace: %w", err)
 	}
 
 	return