Shulou(Shulou.com)06/02 Report--

In this issue, the editor will bring you about the process of K8s operation and maintenance 06-kubectl delete node. The article is rich in content and analyzes and narrates it from a professional point of view. I hope you can get something after reading this article.

one。 This section records the execution of kubectl delete node

Delete is a rough command, which will directly expel the pod on the deleted node and be created by other node (for replicaset), then remove the deleted node from the scope of master management, and master will lose management control over it. If you want to bring node back under control, you must restart kubelet on the node node.

Check all node in advance

Take the deletion of 10.5.0.45 as an example, you can see that the node exists

[root@k8smaster163075 ~] $kubectl get nodesNAME STATUS ROLES AGE VERSION10.5.0.44 Ready SchedulingDisabled 41h v1.11.310.5.0.45 Ready 41h v1.11.310.5.0.46 Ready 41h v1.11.310.5.0.47 Ready 41h v1.11.310.5.0.48 Ready 41h v1.11.310.5 .0.49 Ready 41h v1.11.3 View all pod

10.5.0.45 node has 4 pod

Image.png

Execute kubectl delete node 10.5.0.45 [root@k8smaster163075 ~] $kubectl get pods-n test-kubeasy-k8s-o wide | grep 10.5.0.45atlas-uat-deployment-5b65898567-85jpb 1 to 1 Running 0 14m 10.5.45.104 10.5.0.45atlas-uat-deployment-5b65898567-8l7gm 1 to 1 Running 0 41h 10.5.45.102 10.5.0.45atlas -uat-deployment-5b65898567-cqzj7 1 Running 0 41h 10.5.45.103 10.5.0.45 atlas-uat-deployment-5b65898567-lzp7k 1 Running 0 41h 10.5.45.101 10.5.0.45 [root@k8smaster163075 ~] $kubectl delete node 10.5.0.45node "10.5.0.45" deleted re-view pod See that 4 new pod have been built

Image.png

Master view all node

Node is no longer under the control of master.

Contrast kubectl drain/cordon node

[root@k8smaster163075 ~] $kubectl get nodesNAME STATUS ROLES AGE VERSION10.5.0.44 Ready SchedulingDisabled 41h v1.11.310.5.0.46 Ready 41h v1.11.310.5.0.47 Ready 41h v1.11.310.5.0.48 Ready 41h v1.11.310.5.0.49 Ready 41h v1.11.3ssh to 10.5.0.45 machines

Docker ps View Container is empty

Recovery of [root@docker000045.ppdgdsl.com ~] $docker psCONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMESdelete Node

Restart Node kubelet

Enter master to view node. Node 10.5.0.45 appears. AGE=2m16s has just taken effect.

[root@k8smaster163075 ~] $kubectl get nodesNAME STATUS ROLES AGE VERSION10.5.0.44 Ready SchedulingDisabled 42h v1.11.310.5.0.45 Ready 2m16s v1.11.310.5.0.46 Ready 42h v1.11.310.5.0.47 Ready 42h v1.11.310.5.0.48 Ready 42h v1.11 .310.5.0.49 Ready 42 hours v1.11.3 di. Cordon,drain,delete node distinction

All three commands will cause the node to stop being scheduled, and the later created pod will not continue to be dispatched to the node, but the operation varies in degree of violence.

Cordon stops scheduling

The impact is minimal, only node will be adjusted to SchedulingDisabled.

Create pod after that, and will not be dispatched to this node.

The old pod will not be affected and will still provide services normally.

Resume scheduling

Kubectl uncordon node_namedrain expelling node

First, expel the pod on the node and recreate the other nodes

Next, set the node to * * SchedulingDisabled**

Resume scheduling

Kubectl uncordon node_namedelete Delete Node

First, expel the pod on the node and recreate the other nodes

Then, delete the node,master from the master node to be invisible, lose control over it, and master cannot restore it

To resume scheduling, you need to enter the node node and restart kubelet

Based on the self-registration function of node, the node resumes its use

Systemctl restart kubelet above is the process of K8s operation and maintenance 06-kubectl delete node shared by Xiaobian. If you happen to have similar doubts, please refer to the above analysis to understand. If you want to know more about it, you are welcome to follow the industry information channel.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.