Persist log info in Kubernetes clusters

[taojing2002]

Currently the log info for pods in Kubernetes clusters will disappear if the pods terminate. This is not acceptable in the production env. We may need the cluster level logging to persist the log for pods:

https://kubernetes.io/docs/concepts/cluster-administration/logging/

Matt also mentioned that Nick is running a log service and we can send the cluster level log info to that service as well.

[artntek]

Ask Nick to review log rotation policy (on node machines) and ensure logs being saved on disk for min 6 months. Then revisit EFK in 3.1.0