Get detailed, per-pod network metrics for export to prometheus. Right now it assumes that:
- You are using kubernetes, and the local kubelet API is accessible
- You are using docker
For the most part, a k8s pod maps 1-to-1 to a linux network namespace. This however is not
the case if the pod is using hostNetwork: true. In that case, the pod uses the default
network namespace of the host, and there are no per-pod metrics to collect. Rather than
report something misleading, pod-netstat-exporter just doesn't return any metrics for those
pods.