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
