1、概念
StorageClass是一个存储类，通过创建StorageClass可以动态生成一个存储卷，供k8s用户使用。
使用StorageClass可以根据PVC动态的创建PV，减少管理员手工创建PV的工作。
StorageClass的定义主要包括名称、后端存储的提供者（privisioner）和后端存储的相关参数配置。StorageClass一旦被创建，就无法修改，如需修改，只能删除重建。
2、创建
要使用 StorageClass，我们就得安装对应的自动配置程序，比如本篇文章使用的存储后端是 nfs，那么我们就需要使用到一个 NFS-Subdir-External-Provisioner 的自动配置程序，我们也叫它 Provisioner，
教程：https://github.com/kubernetes-sigs/nfs-subdir-external-provisioner，这个程序使用我们已经配置好的 nfs 服务器，来自动创建持久卷，也就是自动帮我们创建 PV。
自动创建的 PV 以{namespace}-{pvcName}-{pvName} 这样的命名
格式创建在 NFS 服务器上的共享数据目录中
当这个 PV 被回收后会以archieved-{namespace}-{pvcName}-{pvName} 这样的命名格式存在 NFS 服务器上。
在部署NFS-Subdir-External-Provisioner 之前，我们需要先成功安装上 nfs 服务器，安装方法，在前面文章已经讲解过了https://blog.csdn.net/u011837804/article/details/128588864，
2.1、集群环境
[root@k8s-master ~]# kubectl cluster-info
Kubernetes control plane is running at https://10.211.55.11:6443
CoreDNS is running at https://10.211.55.11:6443/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy
To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.
[root@k8s-master ~]#
[root@k8s-master ~]# kubectl get nodes -owide
NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME
k8s-master Ready control-plane 19h v1.25.0 10.211.55.11 <none> CentOS Stream 8 4.18.0-408.el8.x86_64 docker://20.10.22
k8s-node1 Ready <none> 19h v1.25.0 10.211.55.12 <none> CentOS Stream 8 4.18.0-408.el8.x86_64 docker://20.10.22
k8s-node2 Ready <none> 19h v1.25.0 10.211.55.13 <none> CentOS Stream 8 4.18.0-408.el8.x86_64 docker://20.10.22
[root@k8s-master ~]#2.2、创建 ServiceAccount
现在的 Kubernetes 集群大部分是基于 RBAC 的权限控制，所以我们需要创建一个拥有一定权限的 ServiceAccount 与后面要部署的 NFS Subdir Externa Provisioner 组件绑定。
注意：ServiceAccount是必须的，否则将不会动态创建PV，PVC状态一直为Pending
RBAC 资源文件 nfs-rbac.yaml
apiVersion: v1
kind: ServiceAccount
metadata:
name: nfs-client-provisioner
namespace: dev
---
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: dev
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
namespace: dev
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
namespace: dev
subjects:
- kind: ServiceAccount
name: nfs-client-provisioner
namespace: dev
roleRef:
kind: Role
name: leader-locking-nfs-client-provisioner
apiGroup: rbac.authorization.k8s.io
2.3、部署NFS-Subdir-External-Provisioner
我们以master（10.211.55.11）为nfs服务器，共享目录为/root/data/nfs，StorageClass名称为storage-nfs 部署NFS-Subdir-External-Provisioner
创建nfs-provisioner-deploy.yaml
kind: Deployment
apiVersion: apps/v1
metadata:
name: nfs-client-provisioner
namespace: dev
spec:
replicas: 1
selector:
matchLabels:
app: nfs-client-provisioner
strategy:
type: Recreate #设置升级策略为删除再创建(默认为滚动更新)
template:
metadata:
labels:
app: nfs-client-provisioner
spec:
serviceAccountName: nfs-client-provisioner #上一步创建的ServiceAccount名称
containers:
- name: nfs-client-provisioner
image: registry.cn-beijing.aliyuncs.com/mydlq/nfs-subdir-external-provisioner:v4.0.0
volumeMounts:
- name: nfs-client-root
mountPath: /persistentvolumes
env:
- name: PROVISIONER_NAME # Provisioner的名称,以后设置的storageclass要和这个保持一致
value: storage-nfs
- name: NFS_SERVER # NFS服务器地址,需和valumes参数中配置的保持一致
value: 10.211.55.11
- name: NFS_PATH # NFS服务器数据存储目录,需和valumes参数中配置的保持一致
value: /root/data/nfs
- name: ENABLE_LEADER_ELECTION
value: "true"
volumes:
- name: nfs-client-root
nfs:
server: 10.211.55.11 # NFS服务器地址
path: /root/data/nfs # NFS共享目录
执行效果
# 创建
[root@k8s-master ~]# kubectl apply -f nfs-provisioner-deploy.yaml
deployment.apps/nfs-client-provisioner created
[root@k8s-master ~]#
[root@k8s-master ~]#
# 查看
[root@k8s-master ~]# kubectl get deploy,pod -n dev
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/nfs-client-provisioner 1/1 1 1 9s
NAME READY STATUS RESTARTS AGE
pod/nfs-client-provisioner-59b496764-5kts2 1/1 Running 0 9s
[root@k8s-master ~]#2.4、创建 NFS StorageClass
我们在创建 PVC 时经常需要指定 storageClassName 名称，这个参数配置的就是一个 StorageClass 资源名称，PVC 通过指定该参数来选择使用哪个 StorageClass，并与其关联的 Provisioner 组件来动态创建 PV 资源。所以，这里我们需要提前创建一个 Storagelcass 资源。
创建nfs-storageclass.yaml
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
namespace: dev
name: nfs-storage
annotations:
storageclass.kubernetes.io/is-default-class: "false" ## 是否设置为默认的storageclass
provisioner: storage-nfs ## 动态卷分配者名称，必须和上面创建的deploy中环境变量“PROVISIONER_NAME”变量值一致
parameters:
archiveOnDelete: "true" ## 设置为"false"时删除PVC不会保留数据,"true"则保留数据
mountOptions:
- hard ## 指定为硬挂载方式
- nfsvers=4 ## 指定NFS版本,这个需要根据NFS Server版本号设置查看nfs-server版本号
# nfs 服务器版本号查看 其中 “Server nfs v4” 说明版本为4
[root@k8s-master ~]# nfsstat -v
Server packet stats:
packets udp tcp tcpconn
813 0 813 237
Server rpc stats:
calls badcalls badfmt badauth badclnt
585 228 228 0 0
Server reply cache:
hits misses nocache
0 0 585
Server io stats:
read write
0 0
Server read ahead cache:
size 0-10% 10-20% 20-30% 30-40% 40-50% 50-60% 60-70% 70-80% 80-90% 90-100% notfound
32 0 0 0 0 0 0 0 0 0 0 0
Server file handle cache:
lookup anon ncachedir ncachenondir stale
0 0 0 0 0
Server nfs v4:
null compound
8 1% 577 98%
Server nfs v4 operations:
op0-unused op1-unused op2-future access close
0 0% 0 0% 0 0% 36 2% 0 0%
commit create delegpurge delegreturn getattr
0 0% 5 0% 0 0% 0 0% 335 22%
getfh link lock lockt locku
55 3% 0 0% 0 0% 0 0% 0 0%
lookup lookup_root nverify open openattr
51 3% 0 0% 0 0% 0 0% 0 0%
open_conf open_dgrd putfh putpubfh putrootfh
0 0% 0 0% 344 23% 0 0% 21 1%
read readdir readlink remove rename
0 0% 3 0% 0 0% 0 0% 3 0%
renew restorefh savefh secinfo setattr
0 0% 0 0% 3 0% 0 0% 5 0%
setcltid setcltidconf verify write rellockowner
0 0% 0 0% 0 0% 0 0% 0 0%
bc_ctl bind_conn exchange_id create_ses destroy_ses
0 0% 0 0% 17 1% 10 0% 8 0%
free_stateid getdirdeleg getdevinfo getdevlist layoutcommit
0 0% 0 0% 0 0% 0 0% 0 0%
layoutget layoutreturn secinfononam sequence set_ssv
0 0% 0 0% 10 0% 535 36% 0 0%
test_stateid want_deleg destroy_clid reclaim_comp allocate
0 0% 0 0% 7 0% 9 0% 0 0%
copy copy_notify deallocate ioadvise layouterror
0 0% 0 0% 0 0% 0 0% 0 0%
layoutstats offloadcancel offloadstatus readplus seek
0 0% 0 0% 0 0% 0 0% 0 0%
write_same
0 0%
[root@k8s-master ~]#
# nfs客户端版本号查看 其中 “Client nfs v4” 说明客户端版本为4
[root@k8s-node1 ~]# nfsstat -c
Client rpc stats:
calls retrans authrefrsh
586 0 586
Client nfs v4:
null read write commit open
8 1% 0 0% 0 0% 0 0% 0 0%
open_conf open_noat open_dgrd close setattr
0 0% 0 0% 0 0% 0 0% 5 0%
fsinfo renew setclntid confirm lock
30 5% 0 0% 0 0% 0 0% 0 0%
lockt locku access getattr lookup
0 0% 0 0% 36 6% 46 7% 51 8%
lookup_root remove rename link symlink
10 1% 0 0% 3 0% 0 0% 0 0%
create pathconf statfs readlink readdir
5 0% 20 3% 92 15% 0 0% 3 0%
server_caps delegreturn getacl setacl fs_locations
50 8% 0 0% 0 0% 0 0% 0 0%
rel_lkowner secinfo fsid_present exchange_id create_session
0 0% 0 0% 0 0% 17 2% 10 1%
destroy_session sequence get_lease_time reclaim_comp layoutget
8 1% 165 28% 1 0% 9 1% 0 0%
getdevinfo layoutcommit layoutreturn secinfo_no test_stateid
0 0% 0 0% 0 0% 10 1% 0 0%
free_stateid getdevicelist bind_conn_to_ses destroy_clientid seek
0 0% 0 0% 0 0% 7 1% 0 0%
allocate deallocate layoutstats clone
0 0% 0 0% 0 0% 0 0%
执行效果
# 创建
[root@k8s-master ~]# kubectl apply -f nfs-storageclass.yaml
storageclass.storage.k8s.io/nfs-storage created
[root@k8s-master ~]#
# 查看
[root@k8s-master ~]# kubectl get sc -n dev
NAME PROVISIONER RECLAIMPOLICY VOLUMEBINDINGMODE ALLOWVOLUMEEXPANSION AGE
nfs-storage storage-nfs Delete Immediate false 7s3、测试PVC使用StorageClass
创建storage-pvc.yaml
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: storage-pvc
namespace: dev
spec:
storageClassName: nfs-storage ## 需要与上面创建的storageclass的名称一致
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 1Mi执行效果文章来源：https://www.toymoban.com/news/detail-785744.html
# 创建
[root@k8s-master ~]# kubectl apply -f storage-pvc.yaml
persistentvolumeclaim/storage-pvc created
[root@k8s-master ~]#
[root@k8s-master ~]#
# 查看pvc
[root@k8s-master ~]# kubectl get pvc -n dev
NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE
storage-pvc Bound pvc-8b5da590-2436-472e-a671-038822f15252 1Mi RWO nfs-storage 6s
[root@k8s-master ~]#
[root@k8s-master ~]#
# 查看是否动态创建了pv
[root@k8s-master ~]# kubectl get pv -n dev
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE
pvc-8b5da590-2436-472e-a671-038822f15252 1Mi RWO Delete Bound dev/storage-pvc nfs-storage 19s
[root@k8s-master ~]#
# 查看共享目录是否动态创建了文件
[root@k8s-master ~]# cd /root/data/nfs/
[root@k8s-master nfs]# ls
dev-storage-pvc-pvc-8b5da590-2436-472e-a671-038822f15252
[root@k8s-master nfs]#4、异常处理
如果出现异常，请查看https://blog.csdn.net/u011837804/article/details/128693933 需要解决方案文章来源地址https://www.toymoban.com/news/detail-785744.html
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