See https://kep.k8s.io/2371
* Implement new CRI RPCs - `ListPodSandboxStats` and `PodSandboxStats`
* `ListPodSandboxStats` and `PodSandboxStats` which return stats about
pod sandbox. To obtain pod sandbox stats, underlying metrics are
read from the pod sandbox cgroup parent.
* Process info is obtained by calling into the underlying task
* Network stats are taken by looking up network metrics based on the
pod sandbox network namespace path
* Return more detailed stats for cpu and memory for existing container
stats. These metrics use the underlying task's metrics to obtain
stats.
Signed-off-by: David Porter <porterdavid@google.com>
