253 lines
7.1 KiB
Markdown
253 lines
7.1 KiB
Markdown
# 利用NFS动态提供Kubernetes后端存储卷
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本文翻译自nfs-client-provisioner的[说明文档](https://github.com/kubernetes-incubator/external-storage/tree/master/nfs-client)，本文将介绍使用nfs-client-provisioner这个应用，利用NFS Server给Kubernetes作为持久存储的后端，并且动态提供PV。前提条件是有已经安装好的NFS服务器，并且NFS服务器与Kubernetes的Slave节点都能网络连通。
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所有下文用到的文件来自于`git clone https://github.com/kubernetes-incubator/external-storage.git`的nfs-client目录。
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## nfs-client-provisioner
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nfs-client-provisioner 是一个Kubernetes的简易NFS的外部provisioner，本身不提供NFS，需要现有的NFS服务器提供存储
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- PV以 `${namespace}-${pvcName}-${pvName}`的命名格式提供（在NFS服务器上）
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- PV回收的时候以 `archieved-${namespace}-${pvcName}-${pvName}` 的命名格式（在NFS服务器上）
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## 安装部署
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- 修改deployment文件并部署 `deploy/deployment.yaml`
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需要修改的地方只有NFS服务器所在的IP地址（10.10.10.60），以及NFS服务器共享的路径（`/ifs/kubernetes`），两处都需要修改为你实际的NFS服务器和共享目录
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```yaml
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kind: Deployment
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apiVersion: extensions/v1beta1
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metadata:
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name: nfs-client-provisioner
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spec:
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replicas: 1
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strategy:
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type: Recreate
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template:
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metadata:
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labels:
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app: nfs-client-provisioner
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spec:
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serviceAccountName: nfs-client-provisioner
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containers:
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- name: nfs-client-provisioner
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image: quay.io/external_storage/nfs-client-provisioner:latest
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volumeMounts:
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- name: nfs-client-root
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mountPath: /persistentvolumes
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env:
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- name: PROVISIONER_NAME
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value: fuseim.pri/ifs
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- name: NFS_SERVER
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value: 10.10.10.60
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- name: NFS_PATH
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value: /ifs/kubernetes
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volumes:
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- name: nfs-client-root
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nfs:
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server: 10.10.10.60
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path: /ifs/kubernetes
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```
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- 修改StorageClass文件并部署 `deploy/class.yaml`
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此处可以不修改，或者修改provisioner的名字，需要与上面的deployment的PROVISIONER_NAME名字一致。
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```yaml
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apiVersion: storage.k8s.io/v1
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kind: StorageClass
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metadata:
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name: managed-nfs-storage
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provisioner: fuseim.pri/ifs
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```
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## 授权
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如果您的集群启用了RBAC，或者您正在运行OpenShift，则必须授权provisioner。 如果你在非默认的“default”名称空间/项目之外部署，可以编辑`deploy/auth/clusterrolebinding.yaml`或编辑`oadm policy“指令。
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### 如果启用了RBAC
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需要执行如下的命令来授权。
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```bash
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$ kubectl create -f deploy/auth/serviceaccount.yaml
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serviceaccount "nfs-client-provisioner" created
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$ kubectl create -f deploy/auth/clusterrole.yaml
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clusterrole "nfs-client-provisioner-runner" created
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$ kubectl create -f deploy/auth/clusterrolebinding.yaml
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clusterrolebinding "run-nfs-client-provisioner" created
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$ kubectl patch deployment nfs-client-provisioner -p '{"spec":{"template":{"spec":{"serviceAccount":"nfs-client-provisioner"}}}}'
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```
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## 测试
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测试创建PVC
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- `kubectl create -f deploy/test-claim.yaml`
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测试创建POD
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- `kubectl create -f deploy/test-pod.yaml`
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在NFS服务器上的共享目录下的卷子目录中检查创建的NFS PV卷下是否有"SUCCESS" 文件。
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删除测试POD
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- `kubectl delete -f deploy/test-pod.yaml`
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删除测试PVC
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- `kubectl delete -f deploy/test-claim.yaml`
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在NFS服务器上的共享目录下查看NFS的PV卷回收以后是否名字以archived开头。
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## 我的示例
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* NFS服务器配置
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```bash
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# cat /etc/exports
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```
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```ini
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/media/docker *(no_root_squash,rw,sync,no_subtree_check)
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```
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* nfs-deployment.yaml示例
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NFS服务器的地址是ubuntu-master,共享出来的路径是/media/docker，其他不需要修改。
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```bash
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# cat nfs-deployment.yaml
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```
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```yaml
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kind: Deployment
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apiVersion: extensions/v1beta1
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metadata:
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name: nfs-client-provisioner
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spec:
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replicas: 1
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strategy:
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type: Recreate
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template:
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metadata:
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labels:
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app: nfs-client-provisioner
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spec:
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serviceAccountName: nfs-client-provisioner
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containers:
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- name: nfs-client-provisioner
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image: quay.io/external_storage/nfs-client-provisioner:latest
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volumeMounts:
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- name: nfs-client-root
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mountPath: /persistentvolumes
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env:
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- name: PROVISIONER_NAME
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value: fuseim.pri/ifs
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- name: NFS_SERVER
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value: ubuntu-master
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- name: NFS_PATH
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value: /media/docker
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volumes:
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- name: nfs-client-root
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nfs:
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server: ubuntu-master
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path: /media/docker
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```
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* StorageClass示例
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可以修改Class的名字，我的改成了default。
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```bash
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# cat class.yaml
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```
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```yaml
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apiVersion: storage.k8s.io/v1
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kind: StorageClass
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metadata:
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name: default
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provisioner: fuseim.pri/ifs
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```
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* 查看StorageClass
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```bash
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# kubectl get sc
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NAME PROVISIONER AGE
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default fuseim.pri/ifs 2d
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```
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* 设置这个default名字的SC为Kubernetes的默认存储后端
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```bash
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# kubectl patch storageclass default -p '{"metadata": {"annotations":{"storageclass.kubernetes.io/is-default-class":"true"}}}'
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storageclass.storage.k8s.io "default" patched
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# kubectl get sc
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NAME PROVISIONER AGE
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default (default) fuseim.pri/ifs 2d
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```
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* 测试创建PVC
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查看pvc文件
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```bash
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# cat test-claim.yaml
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```
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```yaml
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kind: PersistentVolumeClaim
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apiVersion: v1
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metadata:
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name: test-claim
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spec:
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accessModes:
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- ReadWriteMany
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resources:
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requests:
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storage: 1Mi
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```
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创建PVC
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```bash
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# kubectl apply -f test-claim.yaml
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persistentvolumeclaim "test-claim" created
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root@Ubuntu-master:~/kubernetes/nfs# kubectl get pvc|grep test
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test-claim Bound pvc-fe3cb938-3f15-11e8-b61d-08002795cb26 1Mi RWX default 10s
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# kubectl get pv|grep test
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pvc-fe3cb938-3f15-11e8-b61d-08002795cb26 1Mi RWX Delete Bound default/test-claim default 58s
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```
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* 启动测试POD
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POD文件如下，作用就是在test-claim的PV里touch一个SUCCESS文件。
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```bash
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# cat test-pod.yaml
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```
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```yaml
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kind: Pod
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apiVersion: v1
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metadata:
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name: test-pod
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spec:
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containers:
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- name: test-pod
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image: gcr.io/google_containers/busybox:1.24
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command:
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- "/bin/sh"
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args:
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- "-c"
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- "touch /mnt/SUCCESS && exit 0 || exit 1"
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volumeMounts:
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- name: nfs-pvc
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mountPath: "/mnt"
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restartPolicy: "Never"
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volumes:
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- name: nfs-pvc
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persistentVolumeClaim:
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claimName: test-claim
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```
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启动POD，一会儿POD就是completed状态，说明执行完毕。
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```bash
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# kubectl apply -f test-pod.yaml
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pod "test-pod" created
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kubectl get pod|grep test
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test-pod 0/1 Completed 0 40s
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```
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我们去NFS共享目录查看有没有SUCCESS文件。
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```bash
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# cd default-test-claim-pvc-fe3cb938-3f15-11e8-b61d-08002795cb26
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# ls
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SUCCESS
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```
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说明部署正常，并且可以动态分配NFS的共享卷。
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