Question

我正在运行本地k8s集群，并将PV定义为mysql pod的hostPath。在下面共享所有配置详细信息。

kind: PersistentVolume
apiVersion: v1
metadata:
  name: mysql-pv-volume
  labels:
    type: local
spec:
  storageClassName: manual
  capacity:
    storage: 2Gi
  accessModes:
    - ReadWriteOnce
  hostPath:
    path: "/mnt/data"
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: mysql-pv-claim
spec:
  storageClassName: manual
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 2Gi
---
apiVersion: v1
kind: Service
metadata:
  name: mysql
spec:
  ports:
  - port: 3306
  selector:
    app: mysql
  clusterIP: None
---
apiVersion: apps/v1 # for versions before 1.9.0 use apps/v1beta2
kind: Deployment
metadata:
  name: mysql
spec:
  selector:
    matchLabels:
      app: mysql
  strategy:
    type: Recreate
  template:
    metadata:
      labels:
        app: mysql
    spec:
      containers:
      - image: mysql:5.7
        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

我遇到的问题是mysql pod在k8s集群中运行，当其删除并重新创建时，它将选择任何一个节点并进行部署。因此mysql hostpath始终安装在特定节点上。修复mysql节点或是否有其他选项？如有任何想法，请共享。

Answer 1

您有以下选择

使用节点选择器或节点相似性来确保在创建挂载的节点上调度pod或
使用本地持久卷。 kubernetes 1.14及更高版本支持它

Answer 2

为什么要使用PVC和PV？实际上，对于hostPath，您甚至不需要创建PV对象。就是这样。

如果要重新创建一个Pod来获取使用前一个（状态）的存储，则应使用StatefulSet。

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: web
spec:
  selector:
    matchLabels:
      app: mysql
  serviceName: "mysql"
  replicas: 1
  template:
    metadata:
      labels:
        app: mysql
    spec:
      terminationGracePeriodSeconds: 10
      containers:
      - name: mysql
        image: mysql:5.7
        env:
        - name: MYSQL_ROOT_PASSWORD
          value: password
        ports:
        - containerPort: 3306
          name: mysql
        volumeMounts:
        - name: mysql-persistent-storage
          mountPath: /var/lib/mysql
  volumeClaimTemplates:
  - metadata:
      name: mysql-persistent-storage
    spec:
      accessModes: ["ReadWriteOnce"]
      # storageClassName: "standard"
      resources:
        requests:
          storage: 2Gi

此statefulSet失败，但这是MySQL问题。供参考。

如何在Kubernetes中的单个节点中为特定路径定义PVC

2 个答案: