title: Kubernetes ingress nginx grafana dashboard prometheus data was empty
body: <p>I just completely setup prometheus and grafana dashboard using this tutorial <a href="https://kubernetes.github.io/ingress-nginx/user-guide/monitoring/" rel="nofollow noreferrer">https://kubernetes.github.io/ingress-nginx/user-guide/monitoring/</a>.</p>
  
  <p>I try to query something in prometheus and it was successfully plotting the graph. But when I access my Grafana dashboard with connecting to prometheus data, it returns empty charts like the below pic.</p>
  
  <p><a href="https://i.stack.imgur.com/WpQvU.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/WpQvU.png" alt="Grafana Result"></a></p>
  
  <p>Do I miss something in the step?</p>