HA kubernetes cluster health commands

Question

I was wondering if it's possible to see which component is the primary service(scheduler,controller-manager, etc.) in a multi-master deployment.

Is there any command to show that information?

Thanks in advance.

Answer 1

You can retrieve endpoints yaml and look in the holderIdentity field of the ...kubernetes.io/leader annotation.

Example from my cluster:

~$ kubectl -n kube-system get ep kube-scheduler -o yaml

apiVersion: v1
kind: Endpoints
metadata:
  annotations:
    control-plane.alpha.kubernetes.io/leader: '{"holderIdentity":"cluster-0_9e8c557b-8dc4-11e9-90d3-42010a9c000a","leaseDurationSeconds":15,"acquireTime":"2019-06-13T10:19:10Z","renewTime":"2019-06-13T11:19:20Z","leaderTransitions":19}'
  creationTimestamp: "2019-03-26T13:04:45Z"
  name: kube-scheduler
  namespace: kube-system
  resourceVersion: "923505"
  selfLink: /api/v1/namespaces/kube-system/endpoints/kube-scheduler
  uid: ba115d1b-4fc7-11e9-b783-42010a9c000a