[Kubernetes (K8S) Kubespray] Use Kubespray to upgrade the exist kubernetes (K8S) cluster

Posted on 2021-09-18 Edited on 2023-09-02 In Cloud Native , Kubernetes (K8S) , Kubespray Views: Word count in article: 2.9k Reading time ≈ 3 mins.

Upgrade the exist kubernetes (K8S) cluster

Kubespray handles upgrades the same way it handles initial deployment. That is to say that each component is laid down in a fixed order.

Usages

First, check current all node version(v.1.21.4):

# kubectl get nodes
NAME    STATUS                     ROLES                  AGE   VERSION
node1   Ready                      control-plane,master   8d    v1.21.4
node2   Ready                      control-plane,master   8d    v1.21.4
node3   Ready                      control-plane,master   5d    v1.21.4

# kubectl version
Client Version: version.Info{Major:"1", Minor:"21", GitVersion:"v1.21.4", GitCommit:"3cce4a82b44f032d0cd1a1790e6d2f5a55d20aae", GitTreeState:"clean", BuildDate:"2021-08-11T18:16:05Z", GoVersion:"go1.16.7", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"21", GitVersion:"v1.21.4", GitCommit:"3cce4a82b44f032d0cd1a1790e6d2f5a55d20aae", GitTreeState:"clean", BuildDate:"2021-08-11T18:10:22Z", GoVersion:"go1.16.7", Compiler:"gc", Platform:"linux/amd64"}

Graceful upgrade

Kubespray supports cordon, drain and uncordoning of nodes when performing a cluster upgrade. There is a separate playbook used for this purpose. It is important to note that upgrade-cluster.yml can only be used for upgrading an existing cluster. That means there must be at least 1 kube_control_plane already deployed.

1	# ansible-playbook -i inventory/mycluster/hosts.yaml --private-key ~/.ssh/id_rsa upgrade-cluster.yml -e kube_version=v1.22.1 -b

You can use --limit=NODE_NAME to limit Kubespray to avoid disturbing other nodes in the cluster.

1	# ansible-playbook -i inventory/mycluster/hosts.yaml --private-key ~/.ssh/id_rsa upgrade-cluster.yml -e kube_version=v1.22.1 -b --limit=node3

Check current all node version.

# kubectl get nodes
NAME    STATUS                     ROLES                  AGE   VERSION
node1   Ready                      control-plane,master   8d    v1.22.1
node2   Ready                      control-plane,master   8d    v1.22.1
node3   Ready                      control-plane,master   5d    v1.22.1

# kubectl version
Client Version: version.Info{Major:"1", Minor:"22", GitVersion:"v1.22.1", GitCommit:"632ed300f2c34f6d6d15ca4cef3d3c7073412212", GitTreeState:"clean", BuildDate:"2021-08-19T15:45:37Z", GoVersion:"go1.16.7", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"22", GitVersion:"v1.22.1", GitCommit:"632ed300f2c34f6d6d15ca4cef3d3c7073412212", GitTreeState:"clean", BuildDate:"2021-08-19T15:39:34Z", GoVersion:"go1.16.7", Compiler:"gc", Platform:"linux/amd64"}