第7章：Kubernetes存储

[root@k8s-m1 chp7]# cat emptyDir.yml
apiVersion: v1
kind: Pod
metadata:
  name: emptydir
spec:
  containers:
  - name: write
    image: centos
    command: ["bash","-c","for i in {1..100};do echo $i >> /data/hello;sleep 1;done"]
    volumeMounts:
    - name: data
      mountPath: /data
  - name: read
    image: centos
    command: ["bash","-c","tail -f /data/hello"]
    volumeMounts:
    - name: data
      mountPath: /data
  volumes:
  - name: data
    emptyDir: {}
[root@k8s-m1 chp7]# kubectl apply -f emptyDir.yml
pod/emptydir created
[root@k8s-m1 chp7]# kubectl get po -o wide
NAME                              READY   STATUS    RESTARTS   AGE     IP               NODE     NOMINATED NODE   READINESS GATES
emptydir                          2/2     Running   1          116s    10.244.111.203   k8s-n2   <none>           <none>

[root@k8s-n2 data]# docker ps |grep emptydir
cbaf1b92b4a8        centos                                              "bash -c ‘for i in {…"   About a minute ago   Up About a minute                       k8s_write_emptydir_default_df40c32a-9f0a-44b7-9c17-89c9e9725da2_3
bce0f2607620        centos                                              "bash -c ‘tail -f /d…"   7 minutes ago        Up 7 minutes                            k8s_read_emptydir_default_df40c32a-9f0a-44b7-9c17-89c9e9725da2_0
0b804b8db60f        registry.aliyuncs.com/google_containers/pause:3.2   "/pause"                 7 minutes ago        Up 7 minutes                            k8s_POD_emptydir_default_df40c32a-9f0a-44b7-9c17-89c9e9725da2_0


[root@k8s-n2 data]# pwd
/var/lib/kubelet/pods/df40c32a-9f0a-44b7-9c17-89c9e9725da2/volumes/kubernetes.io~empty-dir/data

[root@k8s-m1 chp7]# cat hostPath.yml
apiVersion: v1
kind: Pod
metadata:
  name: host-path
spec:
  containers:
  - name: centos
    image: centos
    command: ["bash","-c","sleep 36000"]
    volumeMounts:
    - name: data
      mountPath: /data
  volumes:
  - name: data
    hostPath:
      path: /tmp
      type: Directory

[root@k8s-m1 chp7]# kubectl apply -f hostPath.yml
pod/host-path created
[root@k8s-m1 chp7]# kubectl exec host-path -it bash
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl kubectl exec [POD] -- [COMMAND] instead.

[root@host-path data]# pwd
/data
[root@host-path data]# touch test.txt
[root@k8s-m1 ~]# ls -l /tmp/test.txt
-rw-r--r--. 1 root root 5 8月  18 22:25 /tmp/test.txt

yum install nfs-utils -y
[root@k8s-n2 ~]# mkdir /nfs/k8s -p
[root@k8s-n2 ~]# vim /etc/exports
[root@k8s-n2 ~]# cat /etc/exports
/nfs/k8s 10.0.0.0/24(rw,no_root_squash)
# no_root_squash:当登录NFS主机使用共享目录的使用者是root时,其权限将被转换成为匿名使用者,通常它的UID与GID都会变成nobody身份。

[root@k8s-n2 ~]# systemctl restart nfs
[root@k8s-n2 ~]# systemctl enable nfs
Created symlink from /etc/systemd/system/multi-user.target.wants/nfs-server.service to /usr/lib/systemd/system/nfs-server.service.
[root@k8s-n2 ~]#

# 测试
[root@k8s-n1 ~]# mount -t nfs 10.0.0.25:/nfs/k8s /mnt/

[root@k8s-n1 ~]# df -h |grep nfs
10.0.0.25:/nfs/k8s              26G  5.8G   21G   23% /mnt

查看nfs共享目录：
[root@k8s-n2 ~]# showmount -e
Export list for k8s-n2:
/nfs/k8s 10.0.0.0/24

创建应用
[root@k8s-m1 chp7]# cat nfs-deploy.yml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nfs-nginx-deploy
spec:
  selector:
    matchLabels:
      app: nfs-nginx
  replicas: 3
  template:
    metadata:
      labels:
        app: nfs-nginx
    spec:
      containers:
      - name: nginx
        image: nginx
        volumeMounts:
        - name: wwwroot
          mountPath: /usr/share/nginx/html
        ports:
        - containerPort: 80
      volumes:
      - name: wwwroot
        nfs:
          server: 10.0.0.25
          path: /nfs/k8s

[root@k8s-m1 chp7]# kubectl apply -f nfs-deploy.yml
[root@k8s-m1 chp7]# kubectl get pod -o wide|grep nfs
nfs-nginx-deploy-848f4597c9-658ws   1/1     Running            0          2m33s   10.244.111.205   k8s-n2   <none>           <none>
nfs-nginx-deploy-848f4597c9-bzl5w   1/1     Running            0          2m33s   10.244.111.207   k8s-n2   <none>           <none>
nfs-nginx-deploy-848f4597c9-wz422   1/1     Running            0          2m33s   10.244.111.208   k8s-n2   <none>           <none>

在本地创建index 页面，然后在容器中也可以看到文件

[root@k8s-n2 ~]# echo "hello world" >/nfs/k8s/index.html
[root@k8s-m1 chp7]# curl 10.244.111.205
hello world

[root@k8s-m1 chp7]# kubectl exec nfs-nginx-deploy-848f4597c9-wz422 -it -- bash
root@nfs-nginx-deploy-848f4597c9-wz422:/# mount|grep k8s
10.0.0.25:/nfs/k8s on /usr/share/nginx/html type nfs4 (rw,relatime,vers=4.1,rsize=524288,wsize=524288,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=10.0.0.25,local_lock=none,addr=10.0.0.25)

[root@k8s-m1 chp7]# kubectl apply -f pv.yml
persistentvolume/pv0001 created
persistentvolume/pv0002 created
persistentvolume/pv0003 created

[root@k8s-m1 chp7]# kubectl get pv
NAME     CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS      CLAIM   STORAGECLASS   REASON   AGE
pv0001   5Gi        RWX            Recycle          Available                                   53s
pv0002   15Gi       RWX            Recycle          Available                                   53s
pv0003   30Gi       RWX            Recycle          Available                                   53s

[root@k8s-m1 chp7]# kubectl apply -f pvc-deploy.yml
deployment.apps/pvc-ngnix unchanged
persistentvolumeclaim/my-pvc created

[root@k8s-m1 chp7]# kubectl get pvc
NAME     STATUS   VOLUME   CAPACITY   ACCESS MODES   STORAGECLASS   AGE
my-pvc   Bound    pv0001   5Gi        RWX                           12m

[root@k8s-n2 pv0001]# echo "hello pvc" >index.html
[root@k8s-m1 chp7]# curl 10.244.111.209
hello pvc