no metrics for cadvisor

[fengxx]

What happened:
no metrics for cadvisor due to format issue
What you expected to happen:

https://github.com/splunk/fluent-plugin-kubernetes-metrics/blob/develop/lib/fluent/plugin/in_kubernetes_metrics.rb#L600-L631
it seems it looks for metrics with container_name= but cadvisor only have container=, name=, e.g.

container_cpu_system_seconds_total{container="foo",id="id",name="name",namespace="foo",pod="pod-name"} 2356.13 1624427475226

Changes related to Kubernetes 1.16 , pod_name and container_name metric labels removed from cAdvisor metrics.
kubernetes/enhancements#1206
kubernetes/kubernetes#80376

How to reproduce it (as minimally and precisely as possible):

Anything else we need to know?:

Environment:

• Kubernetes version (use kubectl version): 1.19.x
• Others:

[hvaghani221]

Hey @fengxx
Thanks for creating the issue.
I have made changes in metric plugin and is already merged. So it will be available on next release.
Closing the issue. Feel free to reopen the issue or create a new one if needed.