K8S数据持久化之自动创建pv

标签：管理员   uber   request   ram   持久性   capacity   org   重要   质量   

注意：基于NFs创建PV，与PVC。
并且需要创建PV所需的宿主机目录。

二、做实验类比，如果集群中存在两个空间大小不同的PV，PVC如何跟PV关联。
1.创建PV（创建两个空间大小不同的PV，web-pv1和web-pv2）
1.[root@master?yaml]#?vim?web1.yaml???
2.??
3.kind:?PersistentVolume??
4.apiVersion:?v1??
5.metadata:??
6.??name:?web-pv1??
7.spec:??
8.??accessModes:??
9.????-?ReadWriteOnce??????????
10.??capacity:??
11.????storage:?1Gi??
12.??persistentVolumeReclaimPolicy:?Recycle??
13.??storageClassName:?nfs??
14.??nfs:??
15.????path:?/nfsdata/web1??
16.????server:?192.168.1.1??
17.??
18.[root@master?yaml]#?mkdir?/nfsdata/web1??
19.[root@master?yaml]#?kubectl?apply?-f?web1.yaml???
20.persistentvolume/web-pv1?created??
21.[root@master?yaml]#?kubectl?get?pv??
22.NAME??????CAPACITY???ACCESS?MODES???RECLAIM?POLICY???STATUS??????CLAIM?????????????STORAGECLASS???REASON???AGE??
23.web-pv1???1Gi????????RWO????????????Recycle??????????Available?????????????????????nfs?????????????????????7s??

2.创建第二个Pv
1.[root@master?yaml]#?vim?web2.yaml???
2.kind:?PersistentVolume??
3.apiVersion:?v1??
4.metadata:??
5.??name:?web-pv2??
6.spec:??
7.??accessModes:??
8.????-?ReadWriteOnce??
9.??capacity:??
10.????storage:?2Gi??
11.??persistentVolumeReclaimPolicy:?Recycle??
12.??storageClassName:?nfs??
13.??nfs:??
14.????path:?/nfsdata/web2??
15.????server:?192.168.1.1
16.??
17.[root@master?yaml]#?kubectl?apply?-f?web2.yaml???
18.persistentvolume/web-pv2?created??
19.??
20.[root@master?yaml]#?kubectl?get?pv??
21.NAME??????CAPACITY???ACCESS?MODES???RECLAIM?POLICY???STATUS??????CLAIM?????????????STORAGECLASS???REASON???AGE??
22.web-pv1???1Gi????????RWO????????????Recycle??????????Available?????????????????????nfs?????????????????????103s??
23.web-pv2???2Gi????????RWO????????????Recycle??????????Available?????????????????????nfs?????????????????????14s??

3.创建PVCbr/>1.[root@master?yaml]#?vim?web-pvc.yaml???
2.kind:?PersistentVolumeClaim??br/>3.apiVersion:?v1??
4.metadata:??
5.??name:?web-pvc??
6.spec:??
7.??accessModes:??
8.????-?ReadWriteOnce??
9.??resources:??
10.????requests:??
11.??????storage:?1Gi??
12.??storageClassName:?nfs??
13.[root@master?yaml]#?kubectl?apply?-f?web-pvc.yaml???
14.persistentvolumeclaim/web-pvc?created??br/>15.[root@master?yaml]#?kubectl?get?pvc??
16.NAME??????STATUS???VOLUME????CAPACITY???ACCESS?MODES???STORAGECLASS???AGE??br/>17.web-pvc???Bound????web-pv1???1Gi????????RWO????????????nfs????????????5s??
18.[root@master?yaml]#?kubectl?get?pv??
19.NAME??????CAPACITY???ACCESS?MODES???RECLAIM?POLICY???STATUS??????CLAIM?????????????STORAGECLASS???REASON???AGE??
20.web-pv1???1Gi????????RWO????????????Recycle??????????Bound???????default/web-pvc???nfs?????????????????????8m59s??
21.web-pv2???2Gi????????RWO????????????Recycle??????????Available?????????????????????nfs?????????????????????7m30s?
通过上面的实验得出：
如果，K8s集群中，有很多类似的PV，PVC在去向PV申请空间的时候，不仅会考虑名称以及访问控制模式，还会考虑PVC申请空间的大小，会分配最合适大小的PV。

三、分析storageclass 资源对象的作用及优点。
1.使用PV和PVC可以实现数据持久化，假如我们的PV容量为10G，定义访问模式为RWO，而我们PVC申请的存储空间为5G，那么被申请的PV就有容量被浪费掉了，因为访问模式只能被单个节点挂载。还有，我们每次去创建PV也是比较麻烦的，所以这时候就有了动态的自动的创建所需要的PV了（Storage Class）。
Storage Class：即存储类，是K8s资源类型的一种，它是有管理员为管理PV更加方便创建的一个逻辑组，可以按照存储系统的性能高低，或者综合服务质量，备份策略等分类。不过k8s本身不知道类别到底是什么，它这是作为一个描述。
优点：支持PV的动态创建，当用户用到持久性存储时，不必再去提前创建PV，而是直接创建PVC就可以了，非常的方便。
存储类对象的名称很重要，并且除了名称之外，还有三个关键字段：
Provisioner（供给方、提供者）：即提供了存储资源的存储系统。k8s内建有多重供给方，这些供给方的名字都以“kubernetes.io”为前缀。并且还可以自定义。
Parameters（参数）：存储类使用参数描述要关联到的存储卷，注意不同的供给方参数也不同。
ReclaimPlicy：PV的回收策略。
关于Storage Class的详情介绍：
https://www.kubernetes.org.cn/pvpvcstorageclass

2.做一个自动创建PV的实验：
基于nginx运行一个web服务，使用Deployment资源对象，replicas=3.持久化存储目录为默认主目录，使用storageclass自动创建PV。

基于NFS：

1）首先NFS服务的开启：
1.[root@master?yaml]#?yum?install?-y?nfs-utils?rpcbind??#这里注意三台都要安装NFS服务。
2.[root@master?yaml]#?vim?/etc/exports??
3./nfsdata??*(rw,sync,no_root_squash)??
4.[root@master?yaml]#?mkdir?/nfsdata??
5.[root@master?yaml]#?systemctl?start?rpcbind??
6.[root@master?yaml]#?systemctl?start?nfs-server.service???
7.[root@master?yaml]#?showmount?-e??
8.Export?list?for?master:??
9./nfsdata?*??

2）创建RBAC授权：
1.[root@master?yaml]#?vim?rbac-rolebind.yaml??????#为了给SC资源操作K8s集群的权限。??
2.??
3.kind:?Namespace??
4.apiVersion:?v1??
5.metadata:??
6.??name:?lbs-test??
7.---??
8.apiVersion:?v1??
9.kind:?ServiceAccount????????#创建Rbac授权用户。及定义权限。??
10.metadata:??
11.??name:?nfs-provisioner??
12.??namespace:?lbs-test??
13.---??
14.apiVersion:?rbac.authorization.k8s.io/v1??
15.kind:?ClusterRole??
16.metadata:??
17.??name:?nfs-provisioner-runner??
18.??namespace:?lbs-test??
19.rules:??
20.???-??apiGroups:?[""]??
21.??????resources:?["persistentvolumes"]??
22.??????verbs:?["get",?"list",?"watch",?"create",?"delete"]??
23.???-??apiGroups:?[""]??
24.??????resources:?["persistentvolumeclaims"]??
25.??????verbs:?["get",?"list",?"watch",?"update"]??
26.???-??apiGroups:?["storage.k8s.io"]??
27.??????resources:?["storageclasses"]??
28.??????verbs:?["get",?"list",?"watch"]??
29.???-??apiGroups:?[""]??
30.??????resources:?["events"]??
31.??????verbs:?["watch",?"create",?"update",?"patch"]??
32.???-??apiGroups:?[""]??
33.??????resources:?["services",?"endpoints"]??
34.??????verbs:?["get","create","list",?"watch","update"]??
35.???-??apiGroups:?["extensions"]??
36.??????resources:?["podsecuritypolicies"]??
37.??????resourceNames:?["nfs-provisioner"]??
38.??????verbs:?["use"]??
39.---??
40.kind:?ClusterRoleBinding??
41.apiVersion:?rbac.authorization.k8s.io/v1??
42.metadata:??
43.??name:?run-nfs-provisioner??
44.subjects:??
45.??-?kind:?ServiceAccount??
46.????name:?nfs-provisioner??
47.????namespace:?lbs-test??
48.roleRef:??
49.??kind:?ClusterRole??
50.??name:?nfs-provisioner-runner??
51.??apiGroup:?rbac.authorization.k8s.io?

执行yaml文件：

1.[root@master?yaml]#?kubectl?apply?-f?rbac-rolebind.yaml??
namespace/lbh-test?created??
serviceaccount/nfs-provisioner?created??
clusterrole.rbac.authorization.k8s.io/nfs-provisioner-runner?created??
clusterrolebinding.rbac.authorization.k8s.io/run-nfs-provisioner?created??

3）创建nfs-client-provisioner容器：
1.[root@master?yaml]#?vim?nfs-deployment.yaml??
2.??
3.apiVersion:?extensions/v1beta1??
4.kind:?Deployment??
5.metadata:??
6.??name:?nfs-client-provisioner??
7.??namespace:?lbs-test??
8.spec:??
9.??replicas:?1???????#副本数量为1??
10.??strategy:??
11.????type:?Recreate??
12.??template:??
13.????metadata:??
14.??????labels:??
15.????????app:?nfs-client-provisioner??
16.????spec:??
17.??????serviceAccount:?nfs-provisioner???????#指定账户??
18.??????containers:??
19.????????-?name:?nfs-client-provisioner??
20.??????????image:?registry.cn-hangzhou.aliyuncs.com/open-ali/nfs-client-provisioner??????#使用的镜像。??
21.??????????volumeMounts:??
22.????????????-?name:?nfs-client-root??
23.??????????????mountPath:??/persistentvolumes????????#指定容器内的挂载目录??
24.??????????env:??
25.????????????-?name:?PROVISIONER_NAME????????#这是这个容器内置的变量??
26.??????????????value:?lbs-test??????????????#这是上面变量的值（名字）??
27.????????????-?name:?NFS_SERVER??????????????#内置变量，用于指定nfs服务的IP??
28.??????????????value:?192.168.2.50?????????????
29.????????????-?name:?NFS_PATH????????????????#内置变量，指定的是nfs共享的目录??
30.??????????????value:?/nfsdata??
31.??????volumes:??????????????#这下面是指定上面挂载到容器内的nfs的路径及IP??
32.????????-?name:?nfs-client-root??
33.??????????nfs:??
34.????????????server:?192.168.2.50??
35.????????????path:?/nfsdata??

NFS-deployment：
作用：其实它是一个NFS客户端。它通过K8S的内置的NFS驱动挂载远端的NFS服务器到本地目录；然后将自身作为storage provider，关联storage class。

执行yaml文件：br/>1.[root@master?yaml]#?kubectl?apply?-f?nfs-deployment.yaml???
deployment.extensions/nfs-client-provisioner?created

4）创建SC（Storage Class）自动创建pv
1.[root@master?yaml]#?vim?test-storageclass.yaml??
2.apiVersion:?storage.k8s.io/v1??
3.kind:?StorageClass??
4.metadata:??
5.??name:?sc-nfs??
6.??namespace:?lbs-test??????#名称空间??
7.provisioner:?lbs-test??????#这里要与deployment的env环境变量中的value值对应。??
8.reclaimPolicy:?Retain???????#回收策略为：retain。??

执行yaml文件：
1.[root@master?yaml]#?kubectl?apply?-f?test-storageclass.yaml???
storageclass.storage.k8s.io/sc-nfs?created??

5）创建PVC
1.[root@master?yaml]#?vim?test-pvc.yaml??
2.??
3.apiVersion:?v1??
4.kind:?PersistentVolumeClaim??
5.metadata:??
6.??name:?lbs-claim??
7.??namespace:?lbs-test??
8.??
9.spec:??
10.??storageClassName:?sc-nfs?? 需要与storageclass的名字一致
11.??accessModes:??
12.????-?ReadWriteMany??
13.??resources:??
14.????requests:??
15.??????storage:?500Mi??

当我们创建完PVC后，会自动创建一个PV，其目录在NFS共享目录下：
1.[root@master?yaml]#?ls?/nfsdata/??
lbs-test-lbs-claim-pvc-71262c5a-f866-4bc6-a22f-cd49daf13edf??
??
2.[root@master?yaml]#?kubectl?get?pv?-n?lbs-test???
3.NAME???????????????????????????????????????CAPACITY???ACCESS?MODES???RECLAIM?POLICY???STATUS????????CLAIM??????????????????STORAGECLASS???REASON???AGE??
pvc-71262c5a-f866-4bc6-a22f-cd49daf13edf???500Mi??????RWX????????????Delete???????????Bound?????????lbs-test/lbs-claim????sc-nfs??????????????????26m??

6）**基于nginx运行web服务，使用Deployment资源对象，副本数量三个，持久化存储目录为默认主目录。将默认主目录内容，更改为自己的名称，并验证数据自动创建的PV目录下是否有数据。**
创建Deployment资源：
1.[root@master?yaml]#?vim?nginx.yaml??
2.??
3.apiVersion:?extensions/v1beta1??
4.kind:?Deployment??
5.metadata:??
6.??name:?lbs-web??
7.??namespace:?lbs-test??
8.spec:??
9.??replicas:?3??
10.??template:??
11.????metadata:??
12.??????labels:??
13.????????app:?web??
14.????spec:??
15.??????containers:??
16.??????-?name:?nginx??
17.????????image:?nginx??
18.????????volumeMounts:??
19.????????-?name:?lbs-web??
20.??????????mountPath:?/usr/share/nginx/html/?? 
21.??????volumes:??
22.??????-?name:?lbs-web??
23.????????persistentVolumeClaim:??
24.??????????claimName:?lbs-claim??

执行yaml文件，并查看Pod：
1.[root@master?yaml]#?kubectl?apply?-f?nginx.yaml???
2.deployment.extensions/lbh-web?created??
3.??
4.[root@master?yaml]#?kubectl?get?pod?-n?lbs-test???
5.NAME??????????????????????????????????????READY???STATUS????RESTARTS???AGE??
6.lbs-web-6d596b6666-68wls??????????????????1/1?????Running???0??????????2m29s??
7.lbs-web-6d596b6666-k8vz2??????????????????1/1?????Running???0??????????2m29s??
8.lbs-web-6d596b6666-pvppq??????????????????1/1?????Running???0??????????2m29s??

分别进入容器，配置网页根目录：
1.[root@master?yaml]#?kubectl?exec?-it?-n?lbs-test?lbs-web-6d596b6666-68wls?/bin/bash??
2.root@lbs-web-6d596b6666-68wls:/#?cd?/usr/share/nginx/html/??
3.root@lbs-web-6d596b6666-68wls:/usr/share/nginx/html#?echo?123?>?index.html??
4.root@lbs-web-6d596b6666-68wls:/usr/share/nginx/html#?ls??
5.index.html??
6.root@lbs-web-6d596b6666-68wls:/usr/share/nginx/html#?exit??

查看自动创建得分PV目录下是否有数据：
1.[root@master?yaml]#?cat?/nfsdata/lbs-test-lbs-claim-pvc-71262c5a-f866-4bc6-a22f-cd49daf13edf/index.html???
2.123??

访问网页测试：
1.[root@master?yaml]#?kubectl?get?pod?-o?wide?-n?lbs-test???
2.NAME??????????????????????????????????????READY???STATUS????RESTARTS???AGE?????IP???????????NODE?????NOMINATED?NODE???READINESS?GATES??
3.lbs-web-6d596b6666-68wls??????????????????1/1?????Running???0??????????11m?????10.244.2.7???node02???<none>???????????<none>??
4.lbs-web-6d596b6666-k8vz2??????????????????1/1?????Running???0??????????11m?????10.244.2.9???node02???<none>???????????<none>??
5.lbs-web-6d596b6666-pvppq??????????????????1/1?????Running???0??????????11m?????10.244.2.8???node02???<none>???????????<none>??
6.[root@master?yaml]#?curl?10.244.2.7?????
7.123??

K8S数据持久化之自动创建pv

标签：管理员   uber   request   ram   持久性   capacity   org   重要   质量   

原文地址：https://blog.51cto.com/13911055/2471410