在之前分享的文章k8s持久化存儲之pv與pvc實踐中，我們介紹了靜態pv和pvc的使用方法。這篇文章我們就如何使用動態pv進行實踐操作，我們需要用到k8s的又一個資源對象StorageClass，我們使用的後端存儲爲nfs。此篇部署nfs-client-provisioner文章參考GitHub
kubernetes版本：1.16.0
nfs-client-provisioner介紹
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.
譯文：nfs-client是一個自動預配置程序，它使用你現有的和已配置的NFS服務器來通過持久卷聲明支持Kubernetes持久卷的動態預設置。
PV被創建時以 ${namespace}-${pvcName}-${pvName}的格式命名
PV被回收時以 archieved-${namespace}-${pvcName}-${pvName} 的格式命名
在部署nfs-client-provisioner前，我們需要先準備好nfs存儲服務器並在所有node節點上安裝被啓動nfs服務，可參考文章k8s持久化存儲之pv與pvc實踐。
nfs服務器：192.168.248.139
共享存儲目錄：/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" #設置其爲默認存儲後端 provisioner: fuseim.pri/ifs #or choose another name, must match deployment's env PROVISIONER_NAME' parameters: archiveOnDelete: "false" #刪除pvc後，後端存儲上的pv也自動刪除
rbac授權文件
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
準備好以上三個文件後，使用kubectl apply命令應用即可完成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運行狀態和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已經正常運行，sc已經創建成功。接下來我們測試創建幾個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已經創建成功，並自動創建了一個關聯的pv資源對象。我們再查看後端存儲目錄裏面是否生成了對應命名格式的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長的文件夾，這個文件夾的命名方式是不是和我們上面的規則：${namespace}-${pvcName}-${pvName}是一樣的，結果符合我們的預期。
接下來我們部署一個mysql應用，測試下 StorageClass 方式聲明的 PVC 對象
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 10.0.0.1 <none> 443/TCP 93d service/mysql NodePort 10.0.0.19 <none> 3306:30006/TCP 83s
可以看到mysql應用已經正常運行，我們通過任意一個node節點的ip和30006端口連接mysql數據庫測試
[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數據庫連接正常。此時查看nfs存儲，mysql數據庫數據已經持久化到nfs服務器/data/nfs/default-mysql-01-pvc-pvc-eef853e1-f8d8-4ab9-bfd3-05c2a58fd9dc目錄中
[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
另外我們可以看到我們這裏是手動創建的一個 PVC 對象，在實際工作中，使用 StorageClass 更多的是 StatefulSet 類型的服務，StatefulSet 類型的服務我們也可以通過一個 volumeClaimTemplates 屬性來直接使用 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
直接創建上面的對象
[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-01 <none> <none> web-0 1/1 Running 0 32s 10.244.1.167 k8s-node-02 <none> <none> web-1 1/1 Running 0 31s 10.244.0.188 k8s-node-01 <none> <none> web-2 1/1 Running 0 29s 10.244.1.168 k8s-node-02 <none> <none> web-3 1/1 Running 0 27s 10.244.0.189 k8s-node-01 <none> <none> web-4 1/1 Running 0 24s 10.244.1.169 k8s-node-02 <none> <none> web-5 1/1 Running 0 22s 10.244.0.190 k8s-node-01 <none> <none> web-6 1/1 Running 0 21s 10.244.1.170 k8s-node-02 <none> <none> web-7 1/1 Running 0 19s 10.244.0.191 k8s-node-01 <none> <none>
查看存儲上的數據目錄
可以看出可以自動動態的分配nfs存儲卷。以上即爲k8s持久化存儲之storageclass實踐。