k8s使用nfs动态存储（已测试成功）

k8s使用nfs动态存储

 参考：https://github.com/kubernetes-incubator/external-storage/tree/master/nfs-client

1、Kubernetes集群管理员通过提供不同的存储类，可以满足用户不同的服务质量级别、备份策略和任意策略要求的存储需求。动态存储卷供应使用StorageClass进行实现，其允许存储卷按需被创建。如果没有动态存储供应，Kubernetes集群的管理员将不得不通过手工的方式类创建新的存储卷。通过动态存储卷，Kubernetes将能够按照用户的需要，自动创建其需要的存储。

基于StorageClass的动态存储供应整体过程如下图所示：

1）集群管理员预先创建存储类（StorageClass）；

2）用户创建使用存储类的持久化存储声明(PVC：PersistentVolumeClaim)；

3）存储持久化声明通知系统，它需要一个持久化存储(PV: PersistentVolume)；

4）系统读取存储类的信息；

5）系统基于存储类的信息，在后台自动创建PVC需要的PV；

6）用户创建一个使用PVC的Pod；

7）Pod中的应用通过PVC进行数据的持久化；

8）而PVC使用PV进行数据的最终持久化处理。

2、example

0) 首先创建nfs服务，参考另外一篇文章：http://www.cnblogs.com/cuishuai/p/7798154.html

1）创建rbac授权，（如果集群开启了rbac）,非default需要授权

apiVersion: v1
kind: ServiceAccount
metadata:
  name: nfs-client-provisioner
  # replace with namespace where provisioner is deployed
  namespace: default
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: nfs-client-provisioner-runner
rules:
  - apiGroups: [""]
    resources: ["persistentvolumes"]
    verbs: ["get", "list", "watch", "create", "delete"]
  - apiGroups: [""]
    resources: ["persistentvolumeclaims"]
    verbs: ["get", "list", "watch", "update"]
  - apiGroups: ["storage.k8s.io"]
    resources: ["storageclasses"]
    verbs: ["get", "list", "watch"]
  - apiGroups: [""]
    resources: ["events"]
    verbs: ["create", "update", "patch"]
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: run-nfs-client-provisioner
subjects:
  - kind: ServiceAccount
    name: nfs-client-provisioner
    # replace with namespace where provisioner is deployed
    namespace: default
roleRef:
  kind: ClusterRole
  name: nfs-client-provisioner-runner
  apiGroup: rbac.authorization.k8s.io
---
kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: leader-locking-nfs-client-provisioner
  # replace with namespace where provisioner is deployed
  namespace: default
rules:
  - apiGroups: [""]
    resources: ["endpoints"]
    verbs: ["get", "list", "watch", "create", "update", "patch"]
---
kind: RoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: leader-locking-nfs-client-provisioner
  # replace with namespace where provisioner is deployed
  namespace: default
subjects:
  - kind: ServiceAccount
    name: nfs-client-provisioner
    # replace with namespace where provisioner is deployed
    namespace: default
roleRef:
  kind: Role
  name: leader-locking-nfs-client-provisioner
  apiGroup: rbac.authorization.k8s.io

2)创建nfs的nfs-client-provisioner

# cat deployment-nfs.yaml

kind: Deployment
apiVersion: extensions/v1beta1
metadata:
  name: nfs-client-provisioner
spec:
  replicas: 1
  strategy:
    type: Recreate
  template:
    metadata:
      labels:
        app: nfs-client-provisioner
    spec:
      serviceAccountName: nfs-client-provisioner
      containers:
        - name: nfs-client-provisioner
          image: docker.io/xhuaustc/nfs-client-provisioner:latest
          volumeMounts:
            - name: nfs-client-root
              mountPath: /persistentvolumes
          env:
            - name: PROVISIONER_NAME
              value: fuseim.pri/ifs
            - name: NFS_SERVER
              value: 1.14.0.4  # nfs服务ip
            - name: NFS_PATH
              value: /data/nfs/file # nfs路径
      volumes:
        - name: nfs-client-root
          nfs:
            server: 1.14.0.4 # nfs服务ip
            path: /data/nfs/file # nfs路径

！！PS：10.10.229.43是nfs服务的监听地址，/data/opv是nfs共享的目录。

3)创建storageclass

# cat storageclass-nfs.yaml

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: managed-nfs-storage
  annotations:
    storageclass.kubernetes.io/is-default-class: "true" # 设置该storageclass为PVC创建时默认使用的存储机制
provisioner: fuseim.pri/ifs # 匹配deployment中的环境变量'PROVISIONER_NAME'
parameters:
  archiveOnDelete: "true" # "false" 删除PVC时不会保留数据，"true"将保留PVC数据
reclaimPolicy: Delete

！！PS：fuseim.pri/ifs为上面deployment上创建的PROVISIONER_NAME。

4)创建PersistenetVolumeClaim

在存储类被正确创建后，就可以创建PersistenetVolumeClaim来请求StorageClass，而StorageClass将会为PersistenetVolumeClaim自动创建一个可用PersistentVolume。PersistenetVolumeClaim是对PersistenetVolume的声明，即PersistenetVolume为存储的提供者，而PersistenetVolumeClaim为存储的消费者。

# cat pvc.yaml

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  annotations:
    volume.beta.kubernetes.io/storage-class: managed-nfs-storage
    volume.beta.kubernetes.io/storage-provisioner: fuseim.pri/ifs
  name: nfs-claim-pvc
spec:
  accessModes:
  - ReadWriteMany
  resources:
    requests:
      storage: 1Gi

！！PS：nfs-class为上面创建的storageclass的name，10Gi是设置的目录的大小。

5)执行命令

NAMESPACE=`oc project -q`
sed -i'' "s/namespace:.*/namespace: $NAMESPACE/g" rbac.yaml
oc create -f rbac.yaml
oc adm policy add-scc-to-user hostmount-anyuid system:serviceaccount:$NAMESPACE:nfs-client-provisioner

oc create -f nfs-client-provisioner-deployment.yaml
oc create -f strageclass.yaml
oc create -f nfs-pvc.yaml

# 应用配置

spec:
  containers:
  - name: test-pod
    volumeMounts:
      - name: nfs-claim-pvc
        mountPath: "/mnt"
  volumes:
    - name: nfs-pvc
      persistentVolumeClaim:
        claimName: nfs-claim-pvc