Elasticsearch and metricbeat - getting graf for Kubernetes Container CPU usage

Elastic Stack Elasticsearch
1

Hello to everyone!
I use ElasticSearch 6x, MetricBeat 6.2.3 and Grafana 5x
I want to display the graf for Kubernetes Container CPU usage in percents.
There are such fields in metricbeat: kubernetes.container.cpu.usage.nanocore and kubernetes.container.cpu.limit.nanocores. But they are measured in nanocores.
According to this link: Convert nanocore to percentage I sholud do such steps: kubernetes.container.cpu.usage.nanocore/kubernetes.container.cpu.limit.nanocores*100 to getting the percentage. I use formula in metric script (_value/doc['kubernetes.container.cpu.limit.nanocores'].value)*100 where _value is kubernetes.container.cpu.usage.nanocore.
After all of it I get strange graph:

image
image.png1920×1080 366 KB

What I am doing wrong?

2

I am not sure about the output or parameters you use in grafana. I used to kibana so in that case you can find the below image for what I did in the link you attached. That involved painless scripting language. Though I didn't get the output as expected. In case of kibana, they messaged as they are working on getting percentage directly in the visualisations itself.