StatefulSet存储状态

volumeClaimTemplates使用示例

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: web
spec:
  serviceName: "nginx"
  replicas: 2
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.9.1
        ports:
        - containerPort: 80
          name: web
        volumeMounts:
        - name: www
          mountPath: /usr/share/nginx/html
  volumeClaimTemplates:
  - metadata:
      name: www
    spec:
      accessModes:
      - ReadWriteOnce
      storageClassName: "local-storage"
      resources:
        requests:
          storage: 1Gi

凡是被这个 StatefulSet 管理的 Pod，都会声明一个对应的 PVC；而这个 PVC 的定义，就来自于 volumeClaimTemplates 这个模板字段。更重要的是，这个 PVC 的名字，会被分配一个与这个 Pod 完全一致的编号。

# kubectl get persistentvolumeclaims 
NAME                  STATUS    VOLUME          CAPACITY   ACCESS MODES   STORAGECLASS    AGE
example-local-claim   Pending                                             local-storage   44m
www-web-0             Bound     work1-vol2-pv   20Gi       RWO            local-storage   3m41s
www-web-1             Bound     work1-vol1-pv   20Gi       RWO            local-storage   3m38s                                               17m