作者：申红磊，QingCloud 容器解决方案架构师，开源我的项目爱好者，KubeSphere Member
在正式浏览本文之前，先情谊揭示一下：不建议您在生产环境中应用 NFS 存储（特地是 Kubernetes 1.20 或以上版本），起因如下：
- selfLink was empty 在 K8s 集群 v1.20 之前都存在，在 v1.20 之后被删除问题。
- 还有可能引起 failed to obtain lock 和 input/output error 等问题，从而导致 Pod CrashLoopBackOff。此外，局部利用不兼容 NFS，例如 Prometheus 等。
装置 NFS Server
#装置 NFS 服务器端$ sudo apt-get update #执行以下命令确保应用最新软件包$ sudo apt-get install nfs-kernel-server#装置 NFS 客户端$ sudo apt-get install nfs-common# yum$ yum install -y nfs-utils创立共享目录
先查看配置文件 /etc/exports：
$ cat /etc/exports# /etc/exports: the access control list for filesystems which may be exported# to NFS clients. See exports(5).## Example for NFSv2 and NFSv3:# /srv/homes hostname1(rw,sync,no_subtree_check) hostname2(ro,sync,no_subtree_check)## Example for NFSv4:# /srv/nfs4 gss/krb5i(rw,sync,fsid=0,crossmnt,no_subtree_check)# /srv/nfs4/homes gss/krb5i(rw,sync,no_subtree_check)创立共享指标并赋权：
#目录ksha3.2$ mkdir /ksha3.2$ chmod 777 /ksha3.2#目录demo$ mkdir /demo$ chmod 777 /demo#目录/home/ubuntu/nfs/ks3.1$ mkdir /home/ubuntu/nfs/ks3.1$ chmod 777 /home/ubuntu/nfs/ks3.1增加到配置文件中 /etc/exports：
$ vi /etc/exports..../home/ubuntu/nfs/ks3.1 *(rw,sync,no_subtree_check)/mount/ksha3.2 *(rw,sync,no_subtree_check)/mount/demo *(rw,sync,no_subtree_check)#/mnt/ks3.2 139.198.186.39(insecure,rw,sync,anonuid=500,anongid=500)#/mnt/demo 139.198.167.103(rw,sync,no_subtree_check)#此文件的配置格局为：<输入目录> [客户端1 选项（拜访权限,用户映射,其余）] [客户端2 选项（拜访权限,用户映射,其余）]留神：如果共享目录创立有效或者脱漏创立，应用时会报异样如下：
$ mount.nfs: access denied by server while mounting 139.198.168.114:/mnt/demo1#客户端挂载 nfs 共享目录的时候提醒 mount.nfs: access denied by server while mounting。#问题起因：服务器端的共享目录没有设置容许其他人拜访的权限，或者客户端挂载的目录没有权限。#解决办法：在服务器端批改共享目录的权限，胜利连贯。验证
#更新配置文件,从新加载 /etc/exports 的配置：$ exportfs -rv#在 nfs server 上测试 查看本机共享的目录：$ showmount -e 127.0.0.1$ showmount -e localhost$ showmount -e 127.0.0.1Export list for 127.0.0.1:/mount/demo */mount/ksha3.2 */home/ubuntu/nfs/ks3.1 *应用
在其它网络通的机器上，应用 NFS 共享目录。
装置客户端
如果不装置客户端会报：bad option; for several filesystems (e.g. nfs, cifs) you might need a /sbin/mount. helper program.
#apt-get$ apt-get install nfs-common#yum$ yum install nfs-utils在用户机器上进行测试：
#本机创立挂载目录#目录ksha3.2$ mkdir /root/aa$ chmod 777 /root/aa#应用 nfs client 上测试，将 /root/aa 目录挂载到远端 139.198.168.114 的共享存储目录/mount/ksha3.2上$ mount -t nfs 139.198.168.114:/mount/ksha3.2 /root/aa查看：
#应用 df -h 查看$ df -h | grep aa139.198.168.114:/mount/ksha3.2 146G 5.3G 140G 4% /root/aa解绑：
$ umount -t nfs 139.198.168.114:/mnt/ksha3.2 /root/aa#如果卸载的时候提醒：umount:/mnt:device is busy；解决办法：须要退出挂载目录再进行卸载，或者是否NFS server宕机了#须要强制卸载：mount –lf /mnt #此命令也能够：fuser –km /mnt 不倡议用KubeSphere 对接 NFS 动态分配器
可装置 NFS 客户端程序，为了不便用户对接 NFS 服务端，KubeSphere 可装置 NFS 动态分配器，反对动态分配存储卷，调配和回收存储卷过程简便，可对接一个或者多个 NFS 服务端。
当然也能够应用 Kubernetes 官网办法对接 NFS 服务端，这是一种动态调配存储卷办法，调配和回收存储卷过程简单，可对接多个 NFS 服务端。
前提条件
用户对接 NFS 服务端时应确保 KubeSphere 各节点有权限挂载 NFS 服务端文件夹。
操作步骤
以下步骤示例中，NFS 服务端 IP 为 139.198.168.114，NFS 共享文件夹为 /mnt/ksha3.2。
装置 NFS 动态分配器
首先请在这里下载 rbac.yaml，或者间接执行命令：
$ kubectl apply -f https://raw.githubusercontent.com/kubernetes-incubator/external-storage/master/nfs-client/deploy/rbac.yamlserviceaccount/nfs-client-provisioner createdclusterrole.rbac.authorization.k8s.io/nfs-client-provisioner-runner createdclusterrolebinding.rbac.authorization.k8s.io/run-nfs-client-provisioner createdrole.rbac.authorization.k8s.io/leader-locking-nfs-client-provisioner createdrolebinding.rbac.authorization.k8s.io/leader-locking-nfs-client-provisioner created而后下载官网的 nfs provisoner 用处的 deployment。deployment 文件中有几处，请依据本人的状况做批改：
apiVersion: apps/v1kind: Deploymentmetadata: name: nfs-client-provisioner labels: app: nfs-client-provisioner # replace with namespace where provisioner is deployed namespace: defaultspec: 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: nfs/provisioner-229 - name: NFS_SERVER value: 139.198.168.114 - name: NFS_PATH value: /mount/ksha3.2 volumes: - name: nfs-client-root nfs: server: 139.198.168.114 path: /mount/ksha3.2执行创立：
$ kubectl apply -f deployment.yamldeployment.apps/nfs-client-provisioner created接下来下载官网的 class.yaml，而后创立 StorageClass，须要依据理论状况批改参数：
#请依据上方deployment部署时候的provisioner_name做对应的批改，或者没有批改，就不必动apiVersion: storage.k8s.io/v1kind: StorageClassmetadata: name: managed-nfs-storage annotations: "storageclass.kubernetes.io/is-default-class": "false"provisioner: nfs/provisioner-229 # or choose another name, must match deployment's env PROVISIONER_NAME'parameters: archiveOnDelete: "false"执行创立：kubectl apply -f storageclass.yaml。
如果想让这个 NFS 作为默认的 Provisioner, 那么就增加如下的 annotation：
annotations: "storageclass.kubernetes.io/is-default-class": "true"或者标记一个 StorageClass 为默认的 StorageClass, 你须要增加 / 设置注解 storageclass.kubernetes.io/is-default-class=true。
$ kubectl patch storageclass <your-class-name> -p '{"metadata": {"annotations":{"storageclass.kubernetes.io/is-default-class":"true"}}}'# 查看集群中是否已存在 default Storage Class$ kubectl get scNAME PROVISIONER AGEglusterfs (default) kubernetes.io/glusterfs 3d4h验证装置后果
执行以下命令，查看 NFS 动态分配器容器组是否失常运行。
$ kubectl get po -A | grep nfs-clientdefault nfs-client-provisioner-7d69b9f45f-ks94m 1/1 Running 0 9m3s查看 NFS 存储类型
$ kubectl get sc managed-nfs-storageNAME PROVISIONER RECLAIMPOLICY VOLUMEBINDINGMODE ALLOWVOLUMEEXPANSION AGEmanaged-nfs-storage nfs/provisioner-229 Delete Immediate false 6m28s创立和挂载 NFS 存储卷
当初能够通过动态创建 NFS 存储卷和工作负载挂载 NFS 存储卷了。
kind: PersistentVolumeClaimapiVersion: v1metadata: name: demo4nfs namespace: ddddd annotations: kubesphere.io/creator: admin volume.beta.kubernetes.io/storage-provisioner: nfs/provisioner-229 finalizers: - kubernetes.io/pvc-protectionspec: accessModes: - ReadWriteOnce resources: requests: storage: 10Gi storageClassName: managed-nfs-storage volumeMode: Filesystemunexpected error getting claim reference: selfLink was empty, can’t make reference
问题景象
应用 NFS 创立 PV 时，PVC 始终是处于 Pending 状态。
查看 PVC：
$ kubectl get pvc -n dddddNAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGEdemo4nfs Bound pvc-a561ce85-fc0d-42af-948e-6894ac000264 10Gi RWO managed-nfs-storage 32m查看详细信息：
#查看以后pvc的状态信息,发现是在期待volume的创立$ kubectl get pvc -n ddddd查看 nfs-client-provisioner 的日志，是 seltlink was empty 的问题，selfLink was empty 在 K8s 集群 v1.20 之前都存在，在 v1.20 之后被删除，须要在 /etc/kubernetes/manifests/kube-apiserver.yaml 中增加参数。
$ kubectl get pod -n defaultNAME READY STATUS RESTARTS AGEnfs-client-provisioner-7d69b9f45f-ks94m 1/1 Running 0 27m$ kubectl logs -f nfs-client-provisioner-7d69b9f45f-ks94mI0622 09:41:33.606000 1 leaderelection.go:185] attempting to acquire leader lease default/nfs-provisioner-229...E0622 09:41:33.612745 1 event.go:259] Could not construct reference to: '&v1.Endpoints{TypeMeta:v1.TypeMeta{Kind:"", APIVersion:""}, ObjectMeta:v1.ObjectMeta{Name:"nfs-provisioner-229", GenerateName:"", Namespace:"default", SelfLink:"", UID:"e8f19e28-f17f-4b22-9bb8-d4cbe20c796b", ResourceVersion:"23803580", Generation:0, CreationTimestamp:v1.Time{Time:time.Time{wall:0x0, ext:63791487693, loc:(*time.Location)(0x1956800)}}, DeletionTimestamp:(*v1.Time)(nil), DeletionGracePeriodSeconds:(*int64)(nil), Labels:map[string]string(nil), Annotations:map[string]string{"control-plane.alpha.kubernetes.io/leader":"{\"holderIdentity\":\"nfs-client-provisioner-7d69b9f45f-ks94m_8081b417-f20f-11ec-bff3-f64a9f402fda\",\"leaseDurationSeconds\":15,\"acquireTime\":\"2022-06-22T09:41:33Z\",\"renewTime\":\"2022-06-22T09:41:33Z\",\"leaderTransitions\":0}"}, OwnerReferences:[]v1.OwnerReference(nil), Initializers:(*v1.Initializers)(nil), Finalizers:[]string(nil), ClusterName:""}, Subsets:[]v1.EndpointSubset(nil)}' due to: 'selfLink was empty, can't make reference'. Will not report event: 'Normal' 'LeaderElection' 'nfs-client-provisioner-7d69b9f45f-ks94m_8081b417-f20f-11ec-bff3-f64a9f402fda became leader'I0622 09:41:33.612829 1 leaderelection.go:194] successfully acquired lease default/nfs-provisioner-229I0622 09:41:33.612973 1 controller.go:631] Starting provisioner controller nfs/provisioner-229_nfs-client-provisioner-7d69b9f45f-ks94m_8081b417-f20f-11ec-bff3-f64a9f402fda!I0622 09:41:33.713170 1 controller.go:680] Started provisioner controller nfs/provisioner-229_nfs-client-provisioner-7d69b9f45f-ks94m_8081b417-f20f-11ec-bff3-f64a9f402fda!I0622 09:53:33.461902 1 controller.go:987] provision "ddddd/demo4nfs" class "managed-nfs-storage": startedE0622 09:53:33.464213 1 controller.go:1004] provision "ddddd/demo4nfs" class "managed-nfs-storage": unexpected error getting claim reference: selfLink was empty, can't make referenceI0622 09:56:33.623717 1 controller.go:987] provision "ddddd/demo4nfs" class "managed-nfs-storage": startedE0622 09:56:33.625852 1 controller.go:1004] provision "ddddd/demo4nfs" class "managed-nfs-storage": unexpected error getting claim reference: selfLink was empty, can't make reference解决办法
在 kube-apiserver.yaml 文件中增加参数 - --feature-gates=RemoveSelfLink=false。
#应用命令查找一下 kube-apiserver.yaml的地位$ find / -name kube-apiserver.yaml/data/kubernetes/manifests/kube-apiserver.yaml#在文件中增加 - --feature-gates=RemoveSelfLink=false ，如下图$ cat /data/kubernetes/manifests/kube-apiserver.yamlapiVersion: v1kind: Podmetadata: annotations: kubeadm.kubernetes.io/kube-apiserver.advertise-address.endpoint: 192.168.100.25:6443 creationTimestamp: null labels: component: kube-apiserver tier: control-plane name: kube-apiserver namespace: kube-systemspec: containers: - command: - kube-apiserver - --feature-gates=RemoveSelfLink=false - --advertise-address=0.0.0.0 - --allow-privileged=true - --authorization-mode=Node,RBAC - --client-ca-file=/etc/kubernetes/pki/ca.crt - --enable-admission-plugins=NodeRestriction#增加之后应用kubeadm部署的集群会主动加载部署pod#kubeadm装置的apiserver是Static Pod，它的配置文件被批改后，立刻失效。#Kubelet 会监听该文件的变动，当您批改了 /etc/kubenetes/manifest/kube-apiserver.yaml 文件之后，kubelet 将主动终止原有的 #kube-apiserver-{nodename} 的 Pod，并主动创立一个应用了新配置参数的 Pod 作为代替。#如果您有多个 Kubernetes Master 节点，您须要在每一个 Master 节点上都批改该文件，并使各节点上的参数保持一致。#这里需注意如果api-server启动失败 需从新在执行一遍$ kubectl apply -f /etc/kubernetes/manifests/kube-apiserver.yamlGitHub 官网 ISSUES
unexpected error getting claim reference: selfLink was empty, can’t make reference
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