k8s StatefulSet控制器独立存储

k8s-StatefulSet控制器-独立存储

1. StatefulSet控制器-独立存储

• 独享存储：StatefulSet的存储卷使用VolumeClaimTemplate创建，称为卷申请模板，当StatefulSet使用VolumeClaimTemplate创建一个PersistentVolume时，同样也会为每个Pod分配并创建一个编号的PVC，每
• 个PVC绑定对应的PV，从而保证每个Pod都拥有独立的存储。

1.1 headless service示例

apiVersion: v1
kind: Service
metadata:
  name: web
  namespace: default
spec:
  clusterIP: None       #无头服务
  selector:             #容器选择器
    app: nginx          # 指定关联pod名称
  ports:
    - protocol: TCP    # 协议
      port: 80         # service 端口
      targetPort: 80   # 容器端口
  type: ClusterIP    # 服务类型

1.2 statefulset 独享存储文件

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: web
spec:
  serviceName: "web"  # 绑定的服务
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx
        ports:
        - containerPort: 80
          name: web
        # 独享存储
        volumeMounts:
        - name: www
          mountPath: /usr/share/nginx/html
  volumeClaimTemplates:
  - metadata:
      name: www
    spec:
      storageClassName: "managed-nfs-storage"
      accessModes:
      - ReadWriteOnce
      resources:
        requests:
          storage: 1Gi

2. 案例

2. 1 编写headless service示例

[root@k8s-master statefulset]# vim headless-service.yaml 
[root@k8s-master statefulset]# cat headless-service.yaml 
apiVersion: v1
kind: Service
metadata:
  name: web
  namespace: default
spec:
  clusterIP: None       #无头服务
  selector:             #容器选择器
    app: nginx          # 指定关联pod名称
  ports:
    - protocol: TCP    # 协议
      port: 80         # service 端口
      targetPort: 80   # 容器端口
  type: ClusterIP    # 服务类型

2.2 编写statefulset 独享存储文件

[root@k8s-master statefulset]# vim statefulset_pod.yaml 
[root@k8s-master statefulset]# cat statefulset_pod.yaml 
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: web
spec:
  serviceName: "web"  # 绑定的服务
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx
        ports:
        - containerPort: 80
          name: web
        volumeMounts:
        - name: www
          mountPath: /usr/share/nginx/html
  volumeClaimTemplates:
  - metadata:
      name: www
    spec:
      storageClassName: "managed-nfs-storage"
      accessModes:
      - ReadWriteOnce
      resources:
        requests:
          storage: 1Gi

2.3 启动配置文件

[root@k8s-master statefulset]# kubectl apply -f statefulset_pod.yaml 
statefulset.apps/web configured

2.4 验证是否启动

[root@k8s-master statefulset]# kubectl get pods
NAME                                   READY   STATUS    RESTARTS   AGE
nfs-client-provisioner-95c9579-qslkg   1/1     Running   0          5h6m
web-0                                  1/1     Running   0          17m
web-1                                  1/1     Running   0          17m
web-2                                  1/1     Running   0          16m

2.5 验证pvc和pv

[root@k8s-master statefulset]# kubectl get pvc
NAME         STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS          AGE
my-pvc       Bound    my-pv                                      5Gi        RWX                                  3d12h
test-claim   Bound    pvc-998a4c34-f686-4e46-80bf-6d32c005111d   1Gi        RWX            managed-nfs-storage   2d9h
www-web-0    Bound    pvc-3494846e-cfaa-4334-8080-1479a583cb53   1Gi        RWO            managed-nfs-storage   15m
www-web-1    Bound    pvc-fe224ed6-b3e2-4359-975d-d2a5bd22a3a1   1Gi        RWO            managed-nfs-storage   15m
www-web-2    Bound    pvc-a56d4952-bbbe-49c0-8208-7126fc392b20   1Gi        RWO            managed-nfs-storage   15m


[root@k8s-master statefulset]# kubectl get pv
NAME                                       CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS        CLAIM                STORAGECLASS          REASON   AGE
my-pv                                      5Gi        RWX            Retain           Terminating   default/my-pvc                                      3d12h
pvc-3494846e-cfaa-4334-8080-1479a583cb53   1Gi        RWO            Delete           Bound         default/www-web-0    managed-nfs-storage            15m
pvc-998a4c34-f686-4e46-80bf-6d32c005111d   1Gi        RWX            Delete           Bound         default/test-claim   managed-nfs-storage            2d9h
pvc-a56d4952-bbbe-49c0-8208-7126fc392b20   1Gi        RWO            Delete           Bound         default/www-web-2    managed-nfs-storage            15m
pvc-fe224ed6-b3e2-4359-975d-d2a5bd22a3a1   1Gi        RWO            Delete           Bound         default/www-web-1    managed-nfs-storage            15m
test-pv                                    1Gi        RWX            Retain           Available                                                         22m

• 验证nfs存储的

  [root@k8s-node3 ~]# cd /ifs/kubernetes/
  [root@k8s-node3 kubernetes]# ll -a
  总用量 4
  drwxr-xr-x 6 root root 289 1月   2 21:30 .
  drwxr-xr-x 3 root root  24 12月 28 17:36 ..
  drwxrwxrwx 2 root root  24 12月 31 12:37 default-test-claim-pvc-998a4c34-f686-4e46-80bf-6d32c005111d
  drwxrwxrwx 2 root root   6 1月   2 21:30 default-www-web-0-pvc-3494846e-cfaa-4334-8080-1479a583cb53
  drwxrwxrwx 2 root root   6 1月   2 21:30 default-www-web-1-pvc-fe224ed6-b3e2-4359-975d-d2a5bd22a3a1
  drwxrwxrwx 2 root root   6 1月   2 21:30 default-www-web-2-pvc-a56d4952-bbbe-49c0-8208-7126fc392b20
  -rw-r--r-- 1 root root  22 12月 28 20:17 index.html
  
  

  注释： 在这里我们可以看到有web的存储路径

• 往这三个路径写入数据

  echo  ' hello pod 00' > default-www-web-0-pvc-3494846e-cfaa-4334-8080-1479a583cb53/index.html
  
  echo  ' hello pod 01' > default-www-web-1-pvc-fe224ed6-b3e2-4359-975d-d2a5bd22a3a1/index.html
  
  echo  ' hello pod 02' > default-www-web-2-pvc-a56d4952-bbbe-49c0-8208-7126fc392b20/index.html
  

• 验证三个路径里面的数据

  [root@k8s-node3 kubernetes]# cat default-www-web-0-pvc-3494846e-cfaa-4334-8080-1479a583cb53/index.html 
   hello pod 00
  [root@k8s-node3 kubernetes]# cat default-www-web-1-pvc-fe224ed6-b3e2-4359-975d-d2a5bd22a3a1/index.html 
   hello pod 01
  [root@k8s-node3 kubernetes]# cat default-www-web-2-pvc-a56d4952-bbbe-49c0-8208-7126fc392b20/index.html 
   hello pod 02
  

2.6 验证一下请求数据

• 查看pod的IP

  [root@k8s-master statefulset]# kubectl get pods -o wide
  NAME                                   READY   STATUS    RESTARTS   AGE     IP               NODE        NOMINATED NODE   READINESS GATES
  nfs-client-provisioner-95c9579-qslkg   1/1     Running   0          5h19m   10.244.36.92     k8s-node1   <none>           <none>
  web-0                                  1/1     Running   0          29m     10.244.107.220   k8s-node3   <none>           <none>
  web-1                                  1/1     Running   0          29m     10.244.36.94     k8s-node1   <none>           <none>
  web-2                                  1/1     Running   0          29m     10.244.169.149   k8s-node2   <none>           <none>
  

• 模拟浏览器请求

  [root@k8s-master statefulset]# curl 10.244.107.220
   hello pod 00
  [root@k8s-master statefulset]# curl 10.244.36.94
   hello pod 01
  [root@k8s-master statefulset]# curl 10.244.169.149
   hello pod 02
  

3 案例-删除应用测试

3.1 删除pod服务

[root@k8s-master statefulset]# kubectl delete -f statefulset_pod.yaml 
statefulset.apps "web" deleted

3.2 验证服务是否存在

[root@k8s-master statefulset]# kubectl get pods
NAME                                   READY   STATUS    RESTARTS   AGE
nfs-client-provisioner-95c9579-qslkg   1/1     Running   0          5h27m

注释：发现服务已经删除了

3.3 验证pv和pvc是否存在

[root@k8s-master statefulset]# kubectl get pv,pvc
NAME                                                        CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS        CLAIM                STORAGECLASS          REASON   AGE
persistentvolume/my-pv                                      5Gi        RWX            Retain           Terminating   default/my-pvc                                      3d12h
persistentvolume/pvc-3494846e-cfaa-4334-8080-1479a583cb53   1Gi        RWO            Delete           Bound         default/www-web-0    managed-nfs-storage            39m
persistentvolume/pvc-998a4c34-f686-4e46-80bf-6d32c005111d   1Gi        RWX            Delete           Bound         default/test-claim   managed-nfs-storage            2d9h
persistentvolume/pvc-a56d4952-bbbe-49c0-8208-7126fc392b20   1Gi        RWO            Delete           Bound         default/www-web-2    managed-nfs-storage            39m
persistentvolume/pvc-fe224ed6-b3e2-4359-975d-d2a5bd22a3a1   1Gi        RWO            Delete           Bound         default/www-web-1    managed-nfs-storage            39m
persistentvolume/test-pv                                    1Gi        RWX            Retain           Available                                                         45m

NAME                               STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS          AGE
persistentvolumeclaim/my-pvc       Bound    my-pv                                      5Gi        RWX                                  3d12h
persistentvolumeclaim/test-claim   Bound    pvc-998a4c34-f686-4e46-80bf-6d32c005111d   1Gi        RWX            managed-nfs-storage   2d9h
persistentvolumeclaim/www-web-0    Bound    pvc-3494846e-cfaa-4334-8080-1479a583cb53   1Gi        RWO            managed-nfs-storage   39m
persistentvolumeclaim/www-web-1    Bound    pvc-fe224ed6-b3e2-4359-975d-d2a5bd22a3a1   1Gi        RWO            managed-nfs-storage   39m
persistentvolumeclaim/www-web-2    Bound    pvc-a56d4952-bbbe-49c0-8208-7126fc392b20   1Gi        RWO            managed-nfs-storage   39m

注释：发现服务还存在

3.4 重新启动服务看看

• 重启服务

  [root@k8s-master statefulset]# kubectl apply -f statefulset_pod.yaml 
  statefulset.apps/web created
  

• 验证IP是否发生变化

  # 验证IP
  [root@k8s-master statefulset]# kubectl get pods -o wide
  NAME                                   READY   STATUS    RESTARTS   AGE     IP               NODE        NOMINATED NODE   READINESS GATES
  nfs-client-provisioner-95c9579-qslkg   1/1     Running   0          5h19m   10.244.36.92     k8s-node1   <none>           <none>
  web-0                                  1/1     Running   0          29m     10.244.107.220   k8s-node3   <none>           <none>
  web-1                                  1/1     Running   0          29m     10.244.36.94     k8s-node1   <none>           <none>
  web-2                                  1/1     Running   0          29m     10.244.169.149   k8s-node2   <none>           <none>
  
  #重启后的
  [root@k8s-master statefulset]# kubectl get pods -o wide
  NAME                                   READY   STATUS    RESTARTS   AGE     IP               NODE        NOMINATED NODE   READINESS GATES
  nfs-client-provisioner-95c9579-qslkg   1/1     Running   0          5h31m   10.244.36.92     k8s-node1   <none>           <none>
  web-0                                  1/1     Running   0          82s     10.244.107.221   k8s-node3   <none>           <none>
  web-1                                  1/1     Running   0          77s     10.244.36.95     k8s-node1   <none>           <none>
  web-2                                  1/1     Running   0          71s     10.244.169.150   k8s-node2   <none>           <none>
  

  注释： 发现已经发现变化了

• 我们验证一下数据是否一样

  [root@k8s-master statefulset]# curl 10.244.107.221
   hello pod 00
  [root@k8s-master statefulset]# curl 10.244.36.95
   hello pod 01
  [root@k8s-master statefulset]# curl 10.244.169.150
   hello pod 02
  

  注释: 看到数据是没有发生变化的