前提需求 / Rquirements
- 現成的kubernetes集羣
- 持久存儲-PersistentVolume
- 持久存儲容量聲明-PersistentVolumeClaim
創建yaml文件 / Create YAML file
https://raw.githubusercontent...
分別創建 Service、PersistentVolumeClaim、Deployment
apiVersion: v1 kind: Service metadata: name: mysql spec: ports: - port: 3306 selector: app: mysql clusterIP: None --- apiVersion: v1 kind: PersistentVolumeClaim metadata: name: mysql-pv-claim spec: accessModes: - ReadWriteOnce resources: requests: storage: 20Gi --- apiVersion: apps/v1beta2 # for versions before 1.8.0 use apps/v1beta1 kind: Deployment metadata: name: mysql spec: selector: matchLabels: app: mysql strategy: type: Recreate template: metadata:、 labels: app: mysql spec: containers: - image: mysql:5.6 name: mysql env: # Use secret in real usage - name: MYSQL_ROOT_PASSWORD value: password ports: - containerPort: 3306 name: mysql volumeMounts: - name: mysql-persistent-storage mountPath: /var/lib/mysql volumes: - name: mysql-persistent-storage persistentVolumeClaim: claimName: mysql-pv-claim對於PersistentVolumeClaim中Access Modes的解釋：
k8s不會真正檢查存儲的訪問模式或根據訪問模式做訪問限制，只是對真實存儲的描述，最終的控制權在真實的存儲端。目前支持三種訪問模式：
- ReadWriteOnce – PV以read-write 掛載到一個節點
- ReadWriteMany – PV以read-write 方式掛載到多個節點
- ReadOnlyMany – PV以read-only 方式掛載到多個節點
部署YAML文件 / Deploy the Deployment
kubectl create -f https://k8s.io/docs/tasks/run-application/mysql-deployment.yaml
or
kubectl create -f mysql-deployment.yaml查看Deployment的詳細信息
kubectl describe deployment mysql查看Deployment的pods信息
kubectl get pods -l app=mysql檢查PersistentVolumeClaim的信息
kubectl describe pvc mysql-pv-claim進入MySQL實例 / Connet to MySQL
啓動一個MySQL客戶端服務並連接到MySQL
kubectl run -it --rm --image=mysql:5.6 --restart=Never mysql-client -- mysql -h mysql -ppassword升級MySQL應用 / Upgrade MySQL
可以使用 kubectl apply 命令對Deployment中的image或者其它部分進行升級;
針對有狀態應用StatefulSet, 需要注意以下幾點:
Don’t scale the app
This setup is for single-instance apps only. The underlying PersistentVolume can only be mounted to one Pod. For clustered stateful apps, see the StatefulSet documentation.
Use strategy: type: Recreate
in the Deployment configuration YAML file. This instructs Kubernetes to not use rolling updates. Rolling updates will not work, as you cannot have more than one Pod running at a time. The Recreate strategy will stop the first pod before creating a new one with the updated configuration
刪除Deployment / Delete the ployment
Delete the deployed objects by name:
kubectl delete deployment,svc mysql
kubectl delete pvc mysql-pv-claim