Kube-Controller-Manager Adjustment

1.Background

In the cloud-edge collaboration scenario, the edge node is connected to the central control plane through the public network, and the network connection may be unstable. The k8s original node life cycle management logic is not suitable for this unstable network condition. OpenYurt uses a custom nodelifecycle controller to manage the node's life cycle, so we need to disable the native nodelifecycle controller in Kube-Controller-Manager to avoid conflicts.

2. Disable nodelifecycle controller

We can adjust the --controllers configurations of kube-controller-manager to disable nodelifecycle controller。If the original configuration is like --controllers=*,bootstrapsigner,tokencleaner，we can adjust it to --controllers=-nodelifecycle,*,bootstrapsigner,tokencleaner to achieve this。

If kube-controller-manager is deployd as static pod at master node，we can modify the file /etc/kubernetes/manifests/kube-controller-manager.yaml to achieve this。After modification，kube-controller-manager will be restarted automatically。

$ vi /etc/kubernetes/manifests/kube-controller-manager.yaml
apiVersion: v1
kind: Pod
...
spec:
  containers:
  - command:
    - kube-controller-manager
    - --allocate-node-cidrs=true
    - --authentication-kubeconfig=/etc/kubernetes/controller-manager.conf
    ...
    - --controllers=-nodelifecycle,*,bootstrapsigner,tokencleaner #disable nodelifecycle controller
    ...