kubernetes使用NFS共享存储有两种方式：
- 手动方式静态创建所需要的PV和PVC。
- 通过创建PVC动态地创建对应PV，无需手动创建PV。
作为测试，临时在master节点上部署 NFS 服务器。
在 master-1 节点：
#master节点安装
nfs yum -y install nfs-utils
#创建nfs目录
mkdir -p /nfs/data/
#修改权限
chmod -R 777 /nfs/data
#编辑 export 文件,这个文件就是nfs默认的配置文件
vim /etc/exports
/nfs/data *(rw,no_root_squash,sync)
#配置生效
exportfs -r
#查看生效
exportfs
#启动rpcbind、nfs服务
systemctl restart rpcbind && systemctl enable rpcbind
systemctl restart nfs && systemctl enable nfs
#查看 RPC 服务的注册状况
rpcinfo -p localhost
#showmount测试
showmount -e 192.168.88.111
所有node节点安装客户端，开机启动
yum -y install nfs-utils systemctl start nfs && systemctl enable nfs 作为准备工作，我们已经在 k8s-master(192.168.0.248) 节点上搭建了一个 NFS 服务器，目录为 /nfs/data
静态申请PV卷
添加pv卷对应目录,这里创建2个pv卷，则添加2个pv卷的目录作为挂载点。
#创建pv卷对应的目录
mkdir -p /nfs/data/pv001
#配置exportrs(我觉得可以不用这步，因为父目录/nfs/data，已经设为共享文件夹)
vim /etc/exports
/nfs/data *(rw,no_root_squash,sync)
/nfs/data/pv001 *(rw,no_root_squash,sync)
#配置生效
exportfs -r
#重启rpcbind、nfs服务
systemctl restart rpcbind && systemctl restart nfs
创建PV
vim nfs-pv001.yaml
apiVersion: v1
kind: PersistentVolume
metadata:
name: nfs-pv001
labels:
pv: nfs-pv001
spec:
capacity:
storage: 200M #磁盘大小200M
accessModes:
- ReadWriteOnce #多客户可读写
persistentVolumeReclaimPolicy: Recycle
storageClassName: nfs
nfs:
server: /nfs/data/pv001
path: "/usr/local/kubernetes/redis/pv1"
配置说明：
- capacity 指定 PV 的容量为 1G。
- accessModes 指定访问模式为 ReadWriteOnce，支持的访问模式有：
- ReadWriteOnce – PV 能以 read-write 模式 mount 到单个节点。
- ReadOnlyMany – PV 能以 read-only 模式 mount 到多个节点。
- ReadWriteMany – PV 能以 read-write 模式 mount 到多个节点。
- persistentVolumeReclaimPolicy 指定当 PV 的回收策略为 Recycle，支持的策略有：
- Retain – 需要管理员手工回收。
- Recycle – 清除 PV 中的数据，效果相当于执行 rm -rf /thevolume/*。
- Delete – 删除 Storage Provider 上的对应存储资源，例如 AWS EBS、GCE PD、Azure Disk、OpenStack Cinder Volume 等。
- storageClassName 指定 PV 的 class 为 nfs。相当于为 PV 设置了一个分类，PVC 可以指定 class 申请相应 class 的 PV。
- 指定 PV 在 NFS 服务器上对应的目录。
创建pv
[root@sam-master-1 ~]# kubectl apply -f nfs-pv001.yaml
persistentvolume/nfs-pv001 created
[root@sam-master-1 ~]# kubectl get pv
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE
nfs-pv001 200M RWO Recycle Available nfs 17s
STATUS 为 Available，表示 pv就绪，可以被 PVC 申请。
创建PVC
接下来创建一个名为pvc001的PVC，配置文件 nfs-pvc001.yaml 如下：
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: nfs-pvc001
spec:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 200M
storageClassName: nfs
selector:
matchLabels:
pv: nfs-pv001
[root@sam-master-1 ~]# kubectl apply -f nfs-pvc001.yaml
persistentvolumeclaim/nfs-pvc001 created
[root@sam-master-1 ~]#
[root@sam-master-1 ~]# kubectl get pvc
NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE
nfs-pvc001 Bound nfs-pv001 200M RWO nfs 6s
[root@sam-master-1 ~]#
[root@sam-master-1 ~]# kubectl get pv
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE
nfs-pv001 200M RWO Recycle Bound default/nfs-pvc001 nfs 7m44s
这里从 kubectl get pvc 和 kubectl get pv 的输出可以看到 pvc001绑定到pv001，申请成功。注意pvc绑定到对应pv通过labels标签方式实现，也可以不指定，将随机绑定到pv。
验证
Pod 中使用存储了，Pod 配置文件 nfs-pod001.yaml 如下：
kind: Pod
apiVersion: v1
metadata:
name: nfs-pod001
spec:
containers:
- name: myfrontend
image: nginx
volumeMounts:
- mountPath: "/var/www/html"
name: nfs-pv001
volumes:
- name: nfs-pv001
persistentVolumeClaim:
claimName: nfs-pvc001
与使用普通 Volume 的格式类似，在 volumes 中通过 persistentVolumeClaim 指定使用nfs-pvc001申请的 Volume。
执行yaml文件创建nfs-pdo001
[root@sam-master-1 ~]# kubectl apply -f nfs-pod001.yaml
pod/nfs-pod001 created
[root@sam-master-1 ~]# kubectl get pod |grep nfs
nfs-pod001 1/1 Running 0 26s验证 PV 是否可用
验证
[root@sam-master-1 ~]# kubectl exec nfs-pod001 touch /var/www/html/index001.html
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl kubectl exec [POD] -- [COMMAND] instead.
[root@sam-master-1 ~]#
[root@sam-master-1 ~]# ls /nfs/data/pv001/
index001.html
[root@sam-master-1 ~]#
进入pod查看挂载情况
删除 pv
删除 pod，pv 和 pvc 不会被删除，nfs存储的数据不会被删除。
[root@sam-master-1 ~]# kubectl delete -f nfs-pod001.yaml
pod "nfs-pod001" deleted
[root@sam-master-1 ~]# kubectl get pv
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE
nfs-pv001 200M RWO Recycle Bound default/nfs-pvc001 nfs 17m
[root@sam-master-1 ~]#
[root@sam-master-1 ~]# kubectl get pvc
NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE
nfs-pvc001 Bound nfs-pv001 200M RWO nfs 12m
[root@sam-master-1 ~]#
[root@sam-master-1 ~]# ls /nfs/data/pv001/
index001.html
[root@sam-master-1 ~]#
删除 pvc
删除 pvc，pv将被释放，处于 Available 可用状态，并且 nfs 存储中的数据被删除。
[root@sam-master-1 ~]# kubectl get pv
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE
nfs-pv001 200M RWO Recycle Available nfs 22m
[root@sam-master-1 ~]#
[root@sam-master-1 ~]# ls /nfs/data/pv001/
[root@sam-master-1 ~]#
[root@sam-master-1 ~]#
继续删除 pv
[root@sam-master-1 ~]# kubectl delete -f nfs-pv001.yaml
persistentvolume "nfs-pv001" deleted
[root@sam-master-1 ~]#
动态申请 PV 卷
K8S的外部 NFS 驱动，可以按照其工作方式（是作为 NFS server 还是 NFS client）分为两类：
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。将nfs-client驱动做一个deployment部署到K8S集群中，然后对外提供存储服务。
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
部署 nfs-client-provisioner
在 master上操作,即 192.168.0.248
官方：https://github.com/kubernetes-incubator/external-storage.git
修改 deployment.yaml
这里修改的参数包括 NFS 服务器所在的IP地址（192.168.0.248），以及NFS服务器共享的路径（/nfs/data），两处都需要修改为你实际的NFS服务器和共享目录。
apiVersion: apps/v1
kind: Deployment
metadata:
name: nfs-client-provisioner
labels:
app: nfs-client-provisioner
# replace with namespace where provisioner is deployed
namespace: default
spec:
replicas: 1
strategy:
type: Recreate
selector:
matchLabels:
app: nfs-client-provisioner
template:
metadata:
labels:
app: nfs-client-provisioner
spec:
serviceAccountName: nfs-client-provisioner
containers:
- name: nfs-client-provisioner
image: quay.io/external_storage/nfs-client-provisioner:latest
volumeMounts:
- name: nfs-client-root
mountPath: /persistentvolumes
env:
- name: PROVISIONER_NAME
value: fuseim.pri/ifs
- name: NFS_SERVER
value: 192.168.0.248
- name: NFS_PATH
value: /nfs/data
volumes:
- name: nfs-client-root
nfs:
server: 192.168.0.248
path: /nfs/data部署 deployment.yaml
kubectl apply -f deployment.yaml
创建 StorageClass
storage class的定义，需要注意的是：provisioner属性要等于驱动所传入的环境变量PROVISIONER_NAME的值。否则，驱动不知道知道如何绑定storage class。
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。
此处无需修改
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
name: managed-nfs-storage
provisioner: fuseim.pri/ifs # or choose another name, must match deployment's env PROVISIONER_NAME'
parameters:
archiveOnDelete: "false"
部署yaml文件
[root@sam-master-1 ~]# kubectl apply -f class.yaml
[root@sam-master-1 ~]# kubectl get sc
NAME PROVISIONER RECLAIMPOLICY VOLUMEBINDINGMODE ALLOWVOLUMEEXPANSION AGE
nfs-client cluster.local/nfs-nfs-client-provisioner Delete Immediate true 141m
配置授权
如果集群启用了RBAC，则必须执行如下命令授权provisioner。(k8s1.6+默认开启)
此处无需修改
kind: ServiceAccount
apiVersion: v1
metadata:
name: nfs-client-provisioner
---
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
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
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
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
部署yaml文件
kubectl create -f rbac.yaml
测试
https://github.com/kubernetes-retired/external-storage/blob/master/nfs-client/deploy/test-claim.yaml
创建 test-claim.yaml
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: test-claim
annotations:
volume.beta.kubernetes.io/storage-class: "managed-nfs-storage"
spec:
accessModes:
- ReadWriteMany
resources:
requests:
storage: 1Mi
kubectl create -f test-claim.yaml
查看创建的 PVC
可以看到PVC状态为Bound，绑定的volume为 pvc-c6a546cd-68a9-4d73-8eec-f0426df62a9d
[root@sam-master-1 ~]# kubectl get pvc |grep test-claim
test-claim Bound pvc-c6a546cd-68a9-4d73-8eec-f0426df62a9d 1Mi RWX managed-nfs-storage 18s
[root@sam-master-1 ~]#
创建测试Pod
test-pod.yaml
kind: Pod
apiVersion: v1
metadata:
name: test-pod
spec:
containers:
- name: test-pod
image: willdockerhub/busybox:1.24
command:
- "/bin/sh"
args:
- "-c"
- "touch /mnt/SUCCESS && exit 0 || exit 1"
volumeMounts:
- name: nfs-pvc
mountPath: "/mnt"
restartPolicy: "Never"
volumes:
- name: nfs-pvc
persistentVolumeClaim:
claimName: test-claim
清理测试环境
删除测试POD
kubectl delete -f test-pod.yaml
删除测试PVC
kubectl delete -f test-claim.yaml
遇到的问题
[root@sam-master-1 ~]# kubectl describe pvc test-claim
Name: test-claim
Namespace: default
StorageClass: managed-nfs-storage
Status: Pending
Volume:
Labels: <none>
Annotations: volume.beta.kubernetes.io/storage-class: managed-nfs-storage
volume.beta.kubernetes.io/storage-provisioner: fuseim.pri/ifs
Finalizers: [kubernetes.io/pvc-protection]
Capacity:
Access Modes:
VolumeMode: Filesystem
Used By: <none>
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal ExternalProvisioning 8s (x3 over 35s) persistentvolume-controller waiting for a volume to be created, either by external provisioner "fuseim.pri/ifs" or manually created by system administrator
[root@sam-master-1 ~]#
https://github.com/kubernetes-incubator/external-storage/issues/754
试着执行此 yaml
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
name: default-admin-rbac (or whatever)
subjects:
- kind: ServiceAccount
name: default
namespace: default
roleRef:
kind: ClusterRole
name: cluster-admin
apiGroup: rbac.authorization.k8s.io