ks8的数据管理---动态配置StorageClass
1、背景
PV是运维人员来创建的，开发操作PVC，可是大规模集群中可能会有很多PV，如果这些PV都需要运维手动来处理这也是一件很繁琐的事情，所以就有了动态供给概念，也就是Dynamic Provisioning。而我们上面的创建的PV都是静态供给方式，也就是Static Provisioning。而动态供给的关键就是StorageClass，它的作用就是创建PV模板。
创建StorageClass里面需要定义PV属性比如存储类型、大小等；另外创建这种PV需要用到存储插件。最终效果是，用户提交PVC，里面指定存储类型，如果符合我们定义的StorageClass，则会为其自动创建PV并进行绑定。
自动创建PV的机制Dynamic Provisioning
人工管理PV的方式就叫作Static Provisioning
StorageClass对象就是创建PV的模板
定义StorageClass一般包含Name,后端使用存储插件类型,存储插件需要使用到的参数等信息定义好之后相当于定义了一块巨大的存储磁盘
当pvc中定义的storageClassName和StorageClass的Name相同的时候那么StorageClass会自动从巨大的存储磁盘创建一个指定storage大小的pv,创建的pv和pvc进行绑定
StorageClass对象会定义如下两个部分内容
第一 PV的属性. 比如,存储类型
第二 创建这种PV需要用到的存储插件. 比如Ceph等等
StorageClass 支持 Delete 和 Retain 两种 reclaimPolicy，默认是 Delete
k8s根据用户提交的PVC中指定的storageClassName的属性值找到对应的StorageClass.然后调用该StorageClass声明的存储插件创建出需要的PV
有了Dynamic Provisioning机制,运维人员只需要在Kubernetes集群里创建出数量有限的StorageClass对象就可以了
当开发人员提交了包含StorageClass字段的PVC之后,Kubernetes就会根据这个StorageClass创建出对应的PV
在没有StorageClass的情况下运维人员对开发人员定义的每一个pvc都要手动创建一个对应的pv与其进行绑定 这样就会大大的增加创建pv的工作量
2、操作步骤
step1：创建一个StorageClass资源（对应3中的step4）
step2：pvc的yaml中增加spec.storageClassName进行配置（对应3中的step5）
3、NFS的动态PV创建（案例演示，参考官网文档）
kubernetes本身支持的动态PV创建不包括nfs，所以需要使用额外插件实现–》nfs-client
step1：下载nfs-client的相关文件
step2：设置权限
NS=$(kubectl config get-contexts|grep -e "^\*" |awk '{print $5}')
NAMESPACE=${NS:-default}
cat 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: ["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"]
- apiGroups: [""]
resources: ["services", "endpoints"]
verbs: ["get","create","list", "watch","update"]
- apiGroups: ["extensions"]
resources: ["podsecuritypolicies"]
resourceNames: ["nfs-provisioner"]
verbs: ["use"]
---
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
sed -i'' "s/namespace:.*/namespace: $NAMESPACE/g" ./rbac.yaml ./deployment.yaml
kubectl create -f deploy/rbac.yaml
step3：配置nfs-client
cat deployment.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: www.my.com/k8s/nfs-client-provisioner:latest
volumeMounts:
- name: nfs-client-root
mountPath: /persistentvolumes
env:
- name: PROVISIONER_NAME
value: fuseim.pri/ifs
- name: NFS_SERVER
value: 10.10.0.112
- name: NFS_PATH
value: /nfsdata
volumes:
- name: nfs-client-root
nfs:
server: 10.10.0.112
path: /nfsdata
Kunectl create -f deployment.yam
step4: 创建StorageClass
cat class.yaml
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
name: managed-nfs-storage
provisioner: fuseim.pri/ifs # or choose another name, must match deployment's env PROVISIONER_NAME'
parameters:
archiveOnDelete: "false" # # When set to "false" your PVs will not be archived
# by the provisioner upon deletion of the PVC.
kubectl create -f class.yaml
kubectl get sc #查看SC
kubectl describe sc managed-nfs-storage #查看SC详情
step5：创建PVC资源
cat test-claim.yaml
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: test-claim
annotations:
volume.beta.kubernetes.io/storage-class: "managed-nfs-storage"
spec:
accessModes:
- ReadWriteMany
resources:
requests:
storage: 1Mi
cat test-pod.yaml
kind: Pod
apiVersion: v1
metadata:
name: test-pod
spec:
containers:
- name: test-pod
image: www.my.com/k8s/busybox:latest
command:
- "/bin/sh"
args:
- "-c"
- "touch /mnt/SUCCESS && sleep 300"
volumeMounts:
- name: nfs-pvc
mountPath: "/mnt"
restartPolicy: "Never"
volumes:
- name: nfs-pvc
persistentVolumeClaim:
claimName: test-claim
kubectl create -f test-claim.yaml #创建PVC资源
kubectl create -f test-pod.yaml #创建pod资源
kubectl get pvc,pod #查看pod和pvc
4、MySQL 数据库提供持久化存储（静态pv）
step1：创建mysql的命名空间、mysql-pv和mysql-pvc
apiVersion: v1
kind: Namespace # 创建命名空间
metadata:
name: mysql # 定义命名空间的名称为mysql
---
apiVersion: v1
kind: PersistentVolume
metadata: # PV建立不要加名称空间，因为PV属于集群级别的
name: mysql-pv # PV名称
labels: # 这些labels可以不定义
name: mysql-pv
storetype: nfs
spec: # 这里的spec和volumes里面的一样
storageClassName: nfs
accessModes: # 设置访问模型
- ReadWriteOnce
# - ReadWriteMany
# - ReadOnlyMany
capacity: # 设置存储空间大小
storage: 1Gi
persistentVolumeReclaimPolicy: Recycle # 回收策略
nfs:
path: /nfsdata
server: 10.10.0.112
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: mysql-pvc # pvc的名字
namespace: mysql
labels: # 这些labels可以不定义
name: mysql-pvc
storetype: nfs
capacity: 1Gi
spec:
storageClassName: nfs
accessModes: # PVC也需要定义访问模式，不过它的模式一定是和现有PV相同或者是它的子集，否则匹配不到PV
- ReadWriteOnce
resources: # 定义资源要求PV满足这个PVC的要求才会被匹配到
requests:
storage: 1Gi # 定义要求有多大空间
如下图所示
step2：部署mysql
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app: mysql
name: mysql
namespace: mysql
spec:
replicas: 1
selector:
matchLabels:
app: mysql
template:
metadata:
labels:
app: mysql
spec:
containers:
- image: www.my.com/sys/mysql:5.7
name: mysql
env:
- name: MYSQL_ROOT_PASSWORD
value: "123456"
ports:
- containerPort: 3306
name: mysql
volumeMounts:
- name: mysql-storage
mountPath: /var/lib/mysql
volumes:
- name: mysql-storage
persistentVolumeClaim:
claimName: mysql-pvc
会发现mysql的数据已经挂载到了nfs的数据目录中
step3：mysql中添加数据
step4：模拟mysql宕机
关闭mysql服务即可
step5：验证数据一致性
5、nginx提供持久化存储（动态sc）
step1：创建nginx的命名空间、nginx-sc、nginx-pvc
apiVersion: v1
kind: Namespace
metadata:
name: nginx
---
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
name: nginx-nfs-storage
provisioner: fuseim.pri/ifs
parameters:
archiveOnDelete: "false"
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: nginx-pvc
namespace: nginx
spec:
accessModes:
- ReadWriteMany
storageClassName: nginx-nfs-storage
resources:
requests:
storage: 1Gi
如下图所示
step2：部署nginx-deploy和nginx-svc
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app: app
name: app
namespace: nginx
spec:
replicas: 2
selector:
matchLabels:
app: app
template:
metadata:
labels:
app: app
spec:
containers:
- image: www.my.com/web/nginx:v1
name: nginx
ports:
- containerPort: 80
volumeMounts:
- name: nginx-storage
mountPath: /usr/share/nginx/html
volumes:
- name: nginx-storage
persistentVolumeClaim:
claimName: nginx-pvc
---
apiVersion: v1
kind: Service
metadata:
labels:
app: app
name: app
namespace: nginx
spec:
ports:
- port: 8000
protocol: TCP
targetPort: 80
selector:
app: app
type: ClusterIP
如下图所示
step3：验证并测试访问
由于sc底层使用的的是112的nfs，所以nginx的数据也响应在会在112的nfs的共享目录中
