在之前分享的文章k8s持久化存储之pv与pvc实践中，我们介绍了静态pv和pvc的使用方法。这篇文章我们就如何使用动态pv进行实践操作，我们需要用到k8s的又一个资源对象StorageClass，我们使用的后端存储为nfs。此篇部署nfs-client-provisioner文章参考GitHub
kubernetes版本：1.16.0
nfs-client-provisioner介绍
nfs-client is an automatic provisioner that use your existing and already configured NFS server to support dynamic provisioning of Kubernetes Persistent Volumes via Persistent Volume Claims.
译文：nfs-client是一个自动预配置程序，它使用你现有的和已配置的NFS服务器来通过持久卷声明支持Kubernetes持久卷的动态预设置。
PV被创建时以 ${namespace}-${pvcName}-${pvName}的格式命名
PV被回收时以 archieved-${namespace}-${pvcName}-${pvName} 的格式命名
在部署nfs-client-provisioner前，我们需要先准备好nfs存储服务器并在所有node节点上安装被启动nfs服务，可参考文章k8s持久化存储之pv与pvc实践。
nfs服务器：192.168.248.139
共享存储目录：/data/nfs
nfs-client-provisioner部署文件
vim nfs-client-provisioner.yaml
apiVersion: apps/v1 kind: Deployment metadata: name: nfs-client-provisioner namespace: default spec: replicas: 1 selector: matchLabels: app: nfs-client-provisioner strategy: type: Recreate template: metadata: labels: app: nfs-client-provisioner spec: serviceAccountName: nfs-client-provisioner containers: - name: nfs-client-provisioner image: quay.azk8s.cn/external_storage/nfs-client-provisioner:latest volumeMounts: - name: timezone mountPath: /etc/localtime - name: nfs-client-root mountPath: /persistentvolumes env: - name: PROVISIONER_NAME value: fuseim.pri/ifs - name: NFS_SERVER value: 192.168.248.139 - name: NFS_PATH value: /data/nfs volumes: - name: timezone hostPath: path: /usr/share/zoneinfo/Asia/Shanghai - name: nfs-client-root nfs: server: 192.168.248.139 path: /data/nfs
Storageclass部署文件
vim nfs-client-class.yaml
apiVersion: storage.k8s.io/v1 kind: StorageClass metadata: name: managed-nfs-storage annotations: storageclass.kubernetes.io/is-default-class: "true" #设置其为默认存储后端 provisioner: fuseim.pri/ifs #or choose another name, must match deployment's env PROVISIONER_NAME' parameters: archiveOnDelete: "false" #删除pvc后，后端存储上的pv也自动删除
rbac授权文件
vim nfs-client-rbac.yaml
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 namespace: default roleRef: kind: Role name: leader-locking-nfs-client-provisioner apiGroup: rbac.authorization.k8s.io
准备好以上三个文件后，使用kubectl apply命令应用即可完成nfs-client-provisioner的部署。
[root@k8s-master-01 Dynamic-pv]# kubectl apply -f . storageclass.storage.k8s.io/managed-nfs-storage created deployment.apps/nfs-client-provisioner created serviceaccount/nfs-client-provisioner created clusterrole.rbac.authorization.k8s.io/nfs-client-provisioner-runner created clusterrolebinding.rbac.authorization.k8s.io/run-nfs-client-provisioner created role.rbac.authorization.k8s.io/leader-locking-nfs-client-provisioner created rolebinding.rbac.authorization.k8s.io/leader-locking-nfs-client-provisioner created
查看pod运行状态和sc
[root@k8s-master-01 Dynamic-pv]# kubectl get pod,sc NAME READY STATUS RESTARTS AGE pod/nfs-client-provisioner-c676947d-pfpms 1/1 Running 0 107s NAME PROVISIONER AGE storageclass.storage.k8s.io/managed-nfs-storage (default) fuseim.pri/ifs 108s
可以看到nfs-client-provisioner已经正常运行，sc已经创建成功。接下来我们测试创建几个pvc
vim mysql-pvc.yaml
apiVersion: v1 kind: PersistentVolumeClaim metadata: name: mysql-01-pvc # annotations: # volume.beta.kubernetes.io/storage-class: "managed-nfs-storage" spec: accessModes: ["ReadWriteMany"] resources: requests: storage: 10Gi --- apiVersion: v1 kind: PersistentVolumeClaim metadata: name: mysql-02-pvc spec: accessModes: ["ReadWriteMany"] resources: requests: storage: 5Gi --- apiVersion: v1 kind: PersistentVolumeClaim metadata: name: mysql-03-pvc spec: accessModes: ["ReadWriteMany"] resources: requests: storage: 3Gi
[root@k8s-master-01 Dynamic-pv]# kubectl apply -f mysql-pvc.yaml persistentvolumeclaim/mysql-01-pvc created persistentvolumeclaim/mysql-02-pvc created persistentvolumeclaim/mysql-03-pvc created [root@k8s-master-01 Dynamic-pv]# kubectl get pvc,pv NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE persistentvolumeclaim/mysql-01-pvc Bound pvc-eef853e1-f8d8-4ab9-bfd3-05c2a58fd9dc 10Gi RWX managed-nfs-storage 2m54s persistentvolumeclaim/mysql-02-pvc Bound pvc-fc0b8228-81c0-4d91-83b0-6bb20ab37cc3 5Gi RWX managed-nfs-storage 2m54s persistentvolumeclaim/mysql-03-pvc Bound pvc-c6739d7d-4930-49bd-975f-04bffc05dfd6 3Gi RWX managed-nfs-storage 2m54s NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE persistentvolume/pvc-c6739d7d-4930-49bd-975f-04bffc05dfd6 3Gi RWX Delete Bound default/mysql-03-pvc managed-nfs-storage 2m54s persistentvolume/pvc-eef853e1-f8d8-4ab9-bfd3-05c2a58fd9dc 10Gi RWX Delete Bound default/mysql-01-pvc managed-nfs-storage 2m54s persistentvolume/pvc-fc0b8228-81c0-4d91-83b0-6bb20ab37cc3 5Gi RWX Delete Bound default/mysql-02-pvc managed-nfs-storage 2m54s
可以看到pvc已经创建成功，并自动创建了一个关联的pv资源对象。我们再查看后端存储目录里面是否生成了对应命名格式的pv
[root@localhost nfs]# pwd /data/nfs [root@localhost nfs]# ll total 12 drwxrwxrwx 2 root root 4096 Feb 20 10:05 default-mysql-01-pvc-pvc-eef853e1-f8d8-4ab9-bfd3-05c2a58fd9dc drwxrwxrwx 2 root root 4096 Feb 20 10:05 default-mysql-02-pvc-pvc-fc0b8228-81c0-4d91-83b0-6bb20ab37cc3 drwxrwxrwx 2 root root 4096 Feb 20 10:05 default-mysql-03-pvc-pvc-c6739d7d-4930-49bd-975f-04bffc05dfd6
可以看到下面有名字很长的文件夹，这个文件夹的命名方式是不是和我们上面的规则：${namespace}-${pvcName}-${pvName}是一样的，结果符合我们的预期。
接下来我们部署一个mysql应用，测试下 StorageClass 方式声明的 PVC 对象
cat mysql-config.yaml apiVersion: v1 kind: ConfigMap metadata: name: mysql-config data: custom.cnf: | [mysqld] default_storage_engine=innodb skip_external_locking skip_host_cache skip_name_resolve default_authentication_plugin=mysql_native_password
cat mysql-secret.yaml apiVersion: v1 kind: Secret metadata: name: mysql-user-pwd data: mysql-root-pwd: cGFzc3dvcmQ=
cat mysql-deploy.yaml apiVersion: v1 kind: Service metadata: name: mysql spec: type: NodePort ports: - port: 3306 nodePort: 30006 protocol: TCP targetPort: 3306 selector: app: mysql --- apiVersion: apps/v1 kind: Deployment metadata: name: mysql spec: replicas: 1 selector: matchLabels: app: mysql strategy: type: Recreate template: metadata: labels: app: mysql spec: containers: - image: mysql name: mysql imagePullPolicy: IfNotPresent env: - name: MYSQL_ROOT_PASSWORD valueFrom: secretKeyRef: name: mysql-user-pwd key: mysql-root-pwd ports: - containerPort: 3306 name: mysql volumeMounts: - name: mysql-config mountPath: /etc/mysql/conf.d/ - name: mysql-persistent-storage mountPath: /var/lib/mysql - name: timezone mountPath: /etc/localtime volumes: - name: mysql-config configMap: name: mysql-config - name: timezone hostPath: path: /usr/share/zoneinfo/Asia/Shanghai - name: mysql-persistent-storage persistentVolumeClaim: claimName: mysql-01-pvc
[root@k8s-master-01 yaml]# kubectl apply -f . configmap/mysql-config created service/mysql created deployment.apps/mysql created secret/mysql-user-pwd created [root@k8s-master-01 yaml]# kubectl get pod,svc NAME READY STATUS RESTARTS AGE pod/mysql-7c5b5df54c-vrnr8 1/1 Running 0 83s pod/nfs-client-provisioner-c676947d-pfpms 1/1 Running 0 30m NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE service/kubernetes ClusterIP 10.0.0.1443/TCP 93d service/mysql NodePort 10.0.0.19 3306:30006/TCP 83s
可以看到mysql应用已经正常运行，我们通过任意一个node节点的ip和30006端口连接mysql数据库测试
[root@localhost ~]# mysql -uroot -h192.168.248.134 -P30006 -p Enter password: Welcome to the MariaDB monitor. Commands end with ; or \g. Your MySQL connection id is 10 Server version: 8.0.19 MySQL Community Server - GPL Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. MySQL [(none)]> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | | sys | +--------------------+ 4 rows in set (0.01 sec) MySQL [(none)]>
可以看到mysql数据库连接正常。此时查看nfs存储，mysql数据库数据已经持久化到nfs服务器/data/nfs/default-mysql-01-pvc-pvc-eef853e1-f8d8-4ab9-bfd3-05c2a58fd9dc目录中
[root@localhost nfs]# du -sh * 177M default-mysql-01-pvc-pvc-eef853e1-f8d8-4ab9-bfd3-05c2a58fd9dc 4.0K default-mysql-02-pvc-pvc-fc0b8228-81c0-4d91-83b0-6bb20ab37cc3 4.0K default-mysql-03-pvc-pvc-c6739d7d-4930-49bd-975f-04bffc05dfd6 [root@localhost nfs]# cd default-mysql-01-pvc-pvc-eef853e1-f8d8-4ab9-bfd3-05c2a58fd9dc/ [root@localhost default-mysql-01-pvc-pvc-eef853e1-f8d8-4ab9-bfd3-05c2a58fd9dc]# ls auto.cnf binlog.index client-cert.pem ibdata1 ibtmp1 mysql.ibd public_key.pem sys binlog.000001 ca-key.pem client-key.pem ib_logfile0 #innodb_temp performance_schema server-cert.pem undo_001 binlog.000002 ca.pem ib_buffer_pool ib_logfile1 mysql private_key.pem server-key.pem undo_002
另外我们可以看到我们这里是手动创建的一个 PVC 对象，在实际工作中，使用 StorageClass 更多的是 StatefulSet 类型的服务，StatefulSet 类型的服务我们也可以通过一个 volumeClaimTemplates 属性来直接使用 StorageClass，如下
vim web.yaml
apiVersion: v1 kind: Service metadata: name: nginx labels: app: nginx spec: ports: - port: 80 name: web clusterIP: None selector: app: nginx --- apiVersion: apps/v1 kind: StatefulSet metadata: name: web spec: serviceName: "nginx" replicas: 8 selector: matchLabels: app: nginx template: metadata: labels: app: nginx spec: containers: - name: nginx image: nginx imagePullPolicy: IfNotPresent ports: - containerPort: 80 name: web volumeMounts: - name: www mountPath: /usr/share/nginx/html volumeClaimTemplates: - metadata: name: www spec: accessModes: [ "ReadWriteOnce" ] resources: requests: storage: 10Gi
直接创建上面的对象
[root@k8s-master-01 Dynamic-pv]# kubectl apply -f web.yaml service/nginx created statefulset.apps/web created [root@k8s-master-01 Dynamic-pv]# kubectl get pod -o wide NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES nfs-client-provisioner-c676947d-wzwhh 1/1 Running 0 41m 10.244.0.176 k8s-node-01web-0 1/1 Running 0 32s 10.244.1.167 k8s-node-02 web-1 1/1 Running 0 31s 10.244.0.188 k8s-node-01 web-2 1/1 Running 0 29s 10.244.1.168 k8s-node-02 web-3 1/1 Running 0 27s 10.244.0.189 k8s-node-01 web-4 1/1 Running 0 24s 10.244.1.169 k8s-node-02 web-5 1/1 Running 0 22s 10.244.0.190 k8s-node-01 web-6 1/1 Running 0 21s 10.244.1.170 k8s-node-02 web-7 1/1 Running 0 19s 10.244.0.191 k8s-node-01
查看存储上的数据目录
可以看出可以自动动态的分配nfs存储卷。以上即为k8s持久化存储之storageclass实践。