kubernetes数据持久化StorageClass动态供给实现详解

正文

  • 存储类的好处之一便是支持PV的动态供给,它甚至可以直接被视作为PV的创建模版,用户用到持久性存储时,需要通过创建PVC来绑定匹配的PV,此类操作需求较大,或者当管理员手动创建的PV无法满足PVC的所有需求时,系统按PVC的需求标准动态创建适配的PV会为存储管理带来极大的灵活性,不过仅那些属于StorageClass的PVC和PV才能产生绑定关系,即没有指定StorageClass的PVC只能绑定同类的PV。
  • 存储类对象的名称至关重要,它是用户调用的标识,创建存储类对象时,除了名称之外,还需要为其定义三个关键字段。provisioner、parameter和reclaimPolicy。
  • 所以kubernetes提供了一种可以动态分配的工作机制,可用自动创建PV,该机制依赖于StorageClass的API,将某个存储节点划分1T给kubernetes使用,当用户申请5Gi的PVC时,会自动从这1T的存储空间去创建一个5Gi的PV,而后自动与之进行关联绑定。
  • 动态PV供给的启用需要事先创建一个存储类,不同的Provisoner的创建方法各有不同,并非所有的存储卷插件都由Kubernetes内建支持PV动态供给。

基于NFS实现动态供应

由于kubernetes内部不包含NFS驱动,所以需要使用外部驱动nfs-subdir-external-provisioner是一个自动供应器,它使用NFS服务端来支持动态供应。

NFS-subdir-external- provisioner实例负责监视PersistentVolumeClaims请求StorageClass,并自动为它们创建NFS所支持的PresistentVolumes。

GitHub地址: https://github.com/kubernetes-sigs/nfs-subdir-external-provisioner

准备NFS服务端的共享目录

这里的意思是要把哪个目录给kubernetes来使用。把目录共享出来。

[root@kn-server-node02-15 ~]# ll /data/
总用量 0
[root@kn-server-node02-15 ~]# showmount -e 10.0.0.15
Export list for 10.0.0.15:
/data 10.0.0.0/24

安装NFS-Server驱动。

首先创建RBAC权限。

[root@kn-server-master01-13 nfs-provisioner]# cat nfs-rbac.yaml 
apiVersion: v1
kind: ServiceAccount
metadata:
 name: nfs-client-provisioner
 # replace with namespace where provisioner is deployed
 namespace: default
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
 name: nfs-client-provisioner-runner
rules:
 - apiGroups: [""]
 resources: ["nodes"]
 verbs: ["get", "list", "watch"]
 - 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
 # replace with namespace where provisioner is deployed
 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
 # replace with namespace where provisioner is deployed
 namespace: default
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
 # replace with namespace where provisioner is deployed
 namespace: default
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
[root@kn-server-master01-13 nfs-provisioner]# kubectl apply -f nfs-rbac.yaml 
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

部署NFS-Provisioner

[root@kn-server-master01-13 nfs-provisioner]# cat nfs-provisioner-deploy.yaml 
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: k8s.gcr.io/sig-storage/nfs-subdir-external-provisioner:v4.0.2 镜像在国内是拉取不到的,因此为下载下来了放在我的docker hub。 替换为lihuahaitang/nfs-subdir-external-provisioner:v4.0.2
 volumeMounts:
 - name: nfs-client-root
 mountPath: /persistentvolumes
 env:
 - name: PROVISIONER_NAME
 value: k8s-sigs.io/nfs-subdir-external-provisioner NFS-Provisioner的名称,后续StorageClassName要与该名称保持一致
 - name: NFS_SERVER NFS服务器的地址
 value: 10.0.0.15 
 - name: NFS_PATH
 value: /data
 volumes:
 - name: nfs-client-root
 nfs:
 server: 10.0.0.15
 path: /data
[root@kn-server-master01-13 nfs-provisioner]# kubectl apply -f nfs-provisioner-deploy.yaml 
deployment.apps/nfs-client-provisioner created
Pod正常运行。
[root@kn-server-master01-13 nfs-provisioner]# kubectl get pods
NAME READY STATUS RESTARTS AGE
nfs-client-provisioner-57d6d9d5f6-dcxgq 1/1 Running 0 2m25s
describe查看Pod详细信息;
[root@kn-server-master01-13 nfs-provisioner]# kubectl describe pods nfs-client-provisioner-57d6d9d5f6-dcxgq 
Name: nfs-client-provisioner-57d6d9d5f6-dcxgq
Namespace: default
Priority: 0
Node: kn-server-node02-15/10.0.0.15
Start Time: Mon, 28 Nov 2022 11:19:33 +0800
Labels: app=nfs-client-provisioner
 pod-template-hash=57d6d9d5f6
Annotations: <none>
Status: Running
IP: 192.168.2.82
IPs:
 IP: 192.168.2.82
Controlled By: ReplicaSet/nfs-client-provisioner-57d6d9d5f6
Containers:
 nfs-client-provisioner:
 Container ID: docker://b5ea240a8693185be681714747f8e0a9f347492a24920dd68e629effb3a7400f
 Image: k8s.gcr.io/sig-storage/nfs-subdir-external-provisioner:v4.0.2 镜像来自k8s.gcr.io
 Image ID: docker-pullable://k8s.gcr.io/sig-storage/nfs-subdir-external-provisioner@sha256:63d5e04551ec8b5aae83b6f35938ca5ddc50a88d85492d9731810c31591fa4c9
 Port: <none>
 Host Port: <none>
 State: Running
 Started: Mon, 28 Nov 2022 11:20:12 +0800
 Ready: True
 Restart Count: 0
 Environment:
 PROVISIONER_NAME: k8s-sigs.io/nfs-subdir-external-provisioner
 NFS_SERVER: 10.0.0.15
 NFS_PATH: /data
 Mounts:
 /persistentvolumes from nfs-client-root (rw)
 /var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-q2z8w (ro)
Conditions:
 Type Status
 Initialized True 
 Ready True 
 ContainersReady True 
 PodScheduled True 
Volumes:
 nfs-client-root:
 Type: NFS (an NFS mount that lasts the lifetime of a pod)
 Server: 10.0.0.15
 Path: /data
 ReadOnly: false
 kube-api-access-q2z8w:
 Type: Projected (a volume that contains injected data from multiple sources)
 TokenExpirationSeconds: 3607
 ConfigMapName: kube-root-ca.crt
 ConfigMapOptional: <nil>
 DownwardAPI: true
QoS Class: BestEffort
Node-Selectors: <none>
Tolerations: node.kubernetes.io/not-ready:NoExecute op=Exists for 300s
 node.kubernetes.io/unreachable:NoExecute op=Exists for 300s
Events:
 Type Reason Age From Message
 ---- ------ ---- ---- -------
 Normal Scheduled 3m11s default-scheduler Successfully assigned default/nfs-client-provisioner-57d6d9d5f6-dcxgq to kn-server-node02-15
 Normal Pulling 3m11s kubelet Pulling image "k8s.gcr.io/sig-storage/nfs-subdir-external-provisioner:v4.0.2"
 Normal Pulled 2m32s kubelet Successfully pulled image "k8s.gcr.io/sig-storage/nfs-subdir-external-provisioner:v4.0.2" in 38.965869132s
 Normal Created 2m32s kubelet Created container nfs-client-provisioner
 Normal Started 2m32s kubelet Started container nfs-client-provisioner

创建StorageClass

创建NFS StorageClass动态供应商。

[root@kn-server-master01-13 nfs-provisioner]# cat storageclass.yaml 
apiVersion: storage.k8s.io/v1
kind: StorageClass 类型为storageclass
metadata:
 name: nfs-provisioner-storage PVC申请时需明确指定的storageclass名称
 annotations:
 storageclass.kubernetes.io/is-default-class: "true"
provisioner: k8s-sigs.io/nfs-subdir-external-provisioner 供应商名称,必须和上面创建的"PROVISIONER_NAME"保持一致
parameters:
 archiveOnDelete: "false" 如果值为false,删除pvc后也会删除目录内容,"true"则会对数据进行保留
 pathPattern: "${.PVC.namespace}/${.PVC.name}" 创建目录路径的模板,默认为随机命名。
[root@kn-server-master01-13 nfs-provisioner]# kubectl apply -f storageclass.yaml 
storageclass.storage.k8s.io/nfs-provisioner-storage created
storage简写sc
[root@kn-server-master01-13 nfs-provisioner]# kubectl get sc
NAME PROVISIONER RECLAIMPOLICY VOLUMEBINDINGMODE ALLOWVOLUMEEXPANSION AGE
nfs-provisioner-storage k8s-sigs.io/nfs-subdir-external-provisioner Delete Immediate false 3s
describe查看配详细信息。
[root@kn-server-master01-13 nfs-provisioner]# kubectl describe sc 
Name: nfs-provisioner-storage
IsDefaultClass: Yes
Annotations: kubectl.kubernetes.io/last-applied-configuration={"apiVersion":"storage.k8s.io/v1","kind":"StorageClass","metadata":{"annotations":{"storageclass.kubernetes.io/is-default-class":"true"},"name":"nfs-provisioner-storage"},"parameters":{"archiveOnDelete":"false","pathPattern":"${.PVC.namespace}/${.PVC.name}"},"provisioner":"k8s-sigs.io/nfs-subdir-external-provisioner"}
,storageclass.kubernetes.io/is-default-class=true
Provisioner: k8s-sigs.io/nfs-subdir-external-provisioner
Parameters: archiveOnDelete=false,pathPattern=${.PVC.namespace}/${.PVC.name}
AllowVolumeExpansion: <unset>
MountOptions: <none>
ReclaimPolicy: Delete
VolumeBindingMode: Immediate
Events: <none>

创建PVC,自动关联PV

[root@kn-server-master01-13 nfs-provisioner]# cat nfs-pvc-test.yaml 
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
 name: nfs-pvc-test
spec:
 storageClassName: "nfs-provisioner-storage"
 accessModes:
 - ReadWriteMany
 resources:
 requests:
 storage: 0.5Gi
这里的PV的名字是随机的,数据的存储路径是根据pathPattern来定义的。
[root@kn-server-node02-15 data]# ls
default
[root@kn-server-node02-15 data]# ll default/
总用量 0
drwxrwxrwx 2 root root 6 11月 28 13:56 nfs-pvc-test
[root@kn-server-master01-13 pv]# kubectl get pv
pvc-8ed67f7d-d829-4d87-8c66-d8a85f50772f 512Mi RWX Delete Bound default/nfs-pvc-test nfs-provisioner-storage 5m19s
[root@kn-server-master01-13 nfs-provisioner]# kubectl describe pv pvc-8ed67f7d-d829-4d87-8c66-d8a85f50772f
Name: pvc-8ed67f7d-d829-4d87-8c66-d8a85f50772f
Labels: <none>
Annotations: pv.kubernetes.io/provisioned-by: k8s-sigs.io/nfs-subdir-external-provisioner
Finalizers: [kubernetes.io/pv-protection]
StorageClass: nfs-provisioner-storage
Status: Bound
Claim: default/nfs-pvc-test
Reclaim Policy: Delete
Access Modes: RWX
VolumeMode: Filesystem
Capacity: 512Mi
Node Affinity: <none>
Message: 
Source:
 Type: NFS (an NFS mount that lasts the lifetime of a pod)
 Server: 10.0.0.15
 Path: /data/default/nfs-pvc-test
 ReadOnly: false
Events: <none>
describe可用看到更详细的信息
root@kn-server-master01-13 nfs-provisioner]# kubectl describe pvc 
Name: nfs-pvc-test
Namespace: default
StorageClass: nfs-provisioner-storage
Status: Bound
Volume: pvc-8ed67f7d-d829-4d87-8c66-d8a85f50772f
Labels: <none>
Annotations: pv.kubernetes.io/bind-completed: yes
 pv.kubernetes.io/bound-by-controller: yes
 volume.beta.kubernetes.io/storage-provisioner: k8s-sigs.io/nfs-subdir-external-provisioner
Finalizers: [kubernetes.io/pvc-protection]
Capacity: 512Mi 定义的存储大小
Access Modes: RWX 卷的读写
VolumeMode: Filesystem
Used By: <none>
Events:
 Type Reason Age From Message
 ---- ------ ---- ---- -------
 Normal ExternalProvisioning 13m persistentvolume-controller waiting for a volume to be created, either by external provisioner "k8s-sigs.io/nfs-subdir-external-provisioner" or manually created by system administrator
 Normal Provisioning 13m k8s-sigs.io/nfs-subdir-external-provisioner_nfs-client-provisioner-57d6d9d5f6-dcxgq_259532a3-4dba-4183-be6d-8e8b320fc778 External provisioner is provisioning volume for claim "default/nfs-pvc-test"
 Normal ProvisioningSucceeded 13m k8s-sigs.io/nfs-subdir-external-provisioner_nfs-client-provisioner-57d6d9d5f6-dcxgq_259532a3-4dba-4183-be6d-8e8b320fc778 Successfully provisioned volume pvc-8ed67f7d-d829-4d87-8c66-d8a85f50772f

创建Pod,测试数据是否持久。

[root@kn-server-master01-13 nfs-provisioner]# cat nginx-pvc-test.yaml
apiVersion: v1
kind: Pod
metadata:
 name: nginx-sc
spec:
 containers:
 - name: nginx
 image: nginx
 volumeMounts:
 - name: nginx-page
 mountPath: /usr/share/nginx/html
 volumes:
 - name: nginx-page
 persistentVolumeClaim:
 claimName: nfs-pvc-test
[root@kn-server-master01-13 nfs-provisioner]# kubectl apply -f nginx-pvc-test.yaml 
pod/nginx-sc created
[root@kn-server-master01-13 nfs-provisioner]# kubectl describe pvc
Name: nfs-pvc-test
Namespace: default
StorageClass: nfs-provisioner-storage
Status: Bound
Volume: pvc-8ed67f7d-d829-4d87-8c66-d8a85f50772f
Labels: <none>
Annotations: pv.kubernetes.io/bind-completed: yes
 pv.kubernetes.io/bound-by-controller: yes
 volume.beta.kubernetes.io/storage-provisioner: k8s-sigs.io/nfs-subdir-external-provisioner
Finalizers: [kubernetes.io/pvc-protection]
Capacity: 512Mi
Access Modes: RWX
VolumeMode: Filesystem
Used By: nginx-sc 可以看到的是nginx-sc这个Pod在使用这个PVC。
和上面名称是一致的。
[root@kn-server-master01-13 nfs-provisioner]# kubectl get pods nginx-sc
NAME READY STATUS RESTARTS AGE
nginx-sc 1/1 Running 0 2m43s
尝试写入数据
[root@kn-server-node02-15 data]# echo "haitang" > /data/default/nfs-pvc-test/index.html
访问测试。
[root@kn-server-master01-13 nfs-provisioner]# curl 192.168.2.83
haitang
作者:梨花海棠原文地址:https://www.cnblogs.com/xunweidezui/p/16930975.html

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