kube-controller-manager service 与 leader election 有冲突

Created by: zryfish

https://github.com/kubesphere/ks-installer/blob/d59c1983bdef016f970afd9df406ef51a06824b9/roles/ks-monitor/files/prometheus/sources/prometheus-serviceKubeControllerManager.yaml#L1-L7

https://github.com/kubesphere/ks-installer/blob/d59c1983bdef016f970afd9df406ef51a06824b9/roles/ks-monitor/files/prometheus/sources/prometheus-serviceKubeScheduler.yaml#L1-L7

Monitor组件会在 kube-system 下创建 kube-controller-manager 和 kube-scheduler service ，创建 service 意味着产生对应的 endpoint 对象。在 HA 环境下， kube-controller-manager 和 kube-scheduler 会开启 leader-election，并会创建对应的 resource lock 对象，目前配置是 endpoint 对象。

endpoint controller 和 leader election 会同时去更新 endpoint 对象，导致更新失败。

I1106 09:18:28.968433       1 event.go:258] Event(v1.ObjectReference{Kind:"Endpoints", Namespace:"kube-system", Name:"kube-scheduler", UID:"8fb0952e-2907-497e-bb65-6f7c23563c51", APIVersion:"v1", ResourceVersion:"17976", FieldPath:""}): type: 'Warning' reason: 'FailedToUpdateEndpoint' Failed to update endpoint kube-system/kube-scheduler: Operation cannot be fulfilled on endpoints "kube-scheduler": the object has been modified; please apply your changes to the latest version and try again

为避免这种情况发生，将 kube-controller-manager service 和 kube-scheduler service 名称加上 -headless 以区分，例如

apiVersion: v1
kind: Service
metadata:
  labels:
    k8s-app: kube-scheduler
  name: kube-scheduler-headless
  namespace: kube-system