什么是StorageClass
Kubernetes提供了一套可以自动创建PV的机制,即:Dynamic Provisioning.而这个机制的核心在于:StorageClass这个API对象.
StorageClass对象会定义下面两部分内容:
1,PV的属性.比如,存储类型,Volume的大小等.
2,创建这种PV需要用到的存储插件
有了这两个信息之后,Kubernetes就能够根据用户提交的PVC,找到一个对应的StorageClass,之后Kubernetes就会调用该StorageClass声明的存储插件,进而创建出需要的PV.
但是其实使用起来是一件很简单的事情,你只需要根据自己的需求,编写YAML文件即可,然后使用kubectl create命令执行即可
为什么需要StorageClass
要使用 StorageClass,我们就得安装对应的自动配置程序,比如我们这里存储后端使用的是 nfs,那么我们就需要使用到一个 nfs-client 的自动配置程序,我们也叫它 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。
1.自动创建的 PV 以${namespace}-${pvcName}-${pvName}这样的命名格式创建在 NFS 服务器上的共享数据目录中
2.而当这个 PV 被回收后会以archieved-${namespace}-${pvcName}-${pvName}这样的命名格式存在 NFS 服务器上。
如下:
[root@caas data]# ll
total 32
drwxrwxrwx 2 root root 4096 Feb 14 17:57 kubesphere-logging-system-data-elasticsearch-logging-data-0-pvc-80ecbdda-21e7-4bf2-889c-9b0e49933af4
drwxrwxrwx 2 root root 4096 Feb 14 17:57 kubesphere-logging-system-data-elasticsearch-logging-discovery-0-pvc-69015dd6-50c8-4ea8-ab6d-7cf5798157df
drwxrwxrwx 2 root root 4096 Feb 15 10:05 kubesphere-monitoring-system-prometheus-k8s-db-prometheus-k8s-0-pvc-8a269a37-d348-4074-8b3c-4f51ec97e96b
drwx------ 2 root root 16384 Feb 11 16:14 lost+found
[root@caas data]#
搭建storageclass步骤:
1.创建一个可用的NFS Serve
2.创建Service Account.这是用来管控NFS provisioner在k8s集群中运行的权限
3.创建StorageClass.负责建立PVC并调用NFS provisioner进行预定的工作,并让PV与PVC建立管理
4.创建NFS provisioner.有两个功能,一个是在NFS共享目录下创建挂载点(volume),另一个则是建了PV并将PV与NFS的挂载点建立关联
创建StorageClass
- 搭建nfs环境
此处不再阐述步骤 - 创建serviceaccount,便捷rbac.yaml,如下:
apiVersion: v1
kind: ServiceAccount
metadata:
name: nfs-client-provisioner
# replace with namespace where provisioner is deployed
namespace: default #根据实际环境设定namespace,下面类同
---
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
# 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
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
- 创建NFS资源的StorageClass
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
name: managed-nfs-storage
provisioner: nfs-storage #这里的名称要和provisioner配置文件中的环境变量PROVISIONER_NAME保持一致
parameters:
archiveOnDelete: "false"
- 创建NFS provisioner
apiVersion: apps/v1
kind: Deployment
metadata:
name: nfs-client-provisioner
labels:
app: nfs-client-provisioner
# replace with namespace where provisioner is deployed
namespace: default #与RBAC文件中的namespace保持一致
spec:
replicas: 1
selector:
matchLabels:
app: nfs-client-provisioner
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-storage #provisioner名称,请确保该名称与 nfs-StorageClass.yaml文件中的provisioner名称保持一致
- name: NFS_SERVER
value: 172.16.155.227 #NFS Server IP地址
- name: NFS_PATH
value: /data/volumes #NFS挂载卷
volumes:
- name: nfs-client-root
nfs:
server: 172.16.155.227 #NFS Server IP地址
path: /data/volumes #NFS 挂载卷
- 创建pod测试
[root@caas ~]# kubectl get pvc -A
NAMESPACE NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE
kubesphere-logging-system data-elasticsearch-logging-data-0 Bound pvc-80ecbdda-21e7-4bf2-889c-9b0e49933af4 20Gi RWO standard 4d3h
kubesphere-logging-system data-elasticsearch-logging-discovery-0 Bound pvc-69015dd6-50c8-4ea8-ab6d-7cf5798157df 4Gi RWO standard 4d3h
kubesphere-monitoring-system prometheus-k8s-db-prometheus-k8s-0 Bound pvc-8a269a37-d348-4074-8b3c-4f51ec97e96b 20Gi RWO standard 3d4h