Don't log "success" when failing over to original image

changelogs/unreleased/311-dont-log-success-for-failovers.yml

+---
+title: Don't log image scaler fail-overs as successes
+merge_request: 636
+author:
+type: fixed

internal/imageresizer/image_resizer.go

@@ -174,11 +174,15 @@ func (r *Resizer) Inject(w http.ResponseWriter, req *http.Request, paramsData st
 		return
 	}
 
-	if resizeCmd != nil {
-		widthLabelVal := strconv.Itoa(int(params.Width))
-		imageResizeDurations.WithLabelValues(params.ContentType, widthLabelVal).Observe(time.Since(start).Seconds())
+	if resizeCmd == nil {
+		// This means we served the original image because rescaling failed
+		logger.WithFields(*logFields(bytesWritten)).Printf("ImageResizer: Served original")
+		return
 	}
 
+	widthLabelVal := strconv.Itoa(int(params.Width))
+	imageResizeDurations.WithLabelValues(params.ContentType, widthLabelVal).Observe(time.Since(start).Seconds())
+
 	logger.WithFields(*logFields(bytesWritten)).Printf("ImageResizer: Success")
 }