初学 k8s ,记录一下

安装并配置 nfs

1. 在 master 节点 和 worker 节点都需要执行以下安装

   yum -y install nfs-utils rpcbind
   systemctl start rpcbind.service
   systemctl start nfs
   systemctl enable rpcbind.service
   systemctl enable nfs

2. 在 master 节点配置 nfs 目录并设置 export 范围
   mkdir /nfs/data -p
   chown nfsnobody.nfsnobody /nfs/data

   设置配置文件

    cat>>/etc/exports<<EOF
    /nfs/data 192.168.1.0/24(rw,sync,no_root_squash,no_all_squash)
    EOF
   

3. 测试：
   在 master 节点上

    [root@centos7-189 working]# showmount -e 127.0.0.1
    Export list for 127.0.0.1:
    [root@centos7-189 working]# showmount
    Hosts on centos7-189:
    [root@centos7-189 working]# showmount -e 192.168.1.189
    Export list for 192.168.1.189:
    [root@centos7-189 working]# showmount -e 192.168.1.185
    Export list for 192.168.1.185:
    [root@centos7-189 working]# showmount -e 192.168.1.186
    Export list for 192.168.1.186:
   

   在 worker 节点上

    [root@centos7-185 ~]# showmount
    Hosts on centos7-185:
    [root@centos7-185 ~]# showmount -e 127.0.0.1
    Export list for 127.0.0.1:
    [root@centos7-185 ~]# showmount -e 192.168.1.185
    Export list for 192.168.1.185:
   

创建 pv、pvc

1. 创建pv配置文件
   # cat pv.yaml

    apiVersion: v1
    kind: PersistentVolume
    metadata:
      name: nfs-pv
      namespace: default
      labels:
        pv: nfs-pv
    spec:
      capacity:
        storage: 100Mi
      accessModes:
        - ReadWriteMany
      persistentVolumeReclaimPolicy: Retain
      storageClassName: nfs-pv
      nfs:  
        server: 192.168.0.141
        path: "/nfs/data/nginx"   #NFS目录，需要该目录在NFS上存在
   

2. 创建pv
   # kubectl create -f pv.yaml

    persistentvolume/nfs-pv created
   

3. 获取pv
   # kubectl get pv

    NAME     CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS      CLAIM   STORAGECLASS   REASON   AGE
    nfs-pv   100Mi      RWX            Retain           Available           nfs-pv                  11s
   

4. 创建 pvc.yaml
   # cat pvc.yaml

    apiVersion: v1
    kind: PersistentVolumeClaim
    metadata:
      name: nfs-pvc
      namespace: default
    spec:
      storageClassName: nfs-pv
      accessModes:
        - ReadWriteMany
      resources:
        requests:
          storage: 50Mi  #容量
   

5. 创建 pvc
   # kubectl create -f pvc.yaml

    persistentvolumeclaim/nfs-pvc created
   

6. 获取pvc
   # kubectl get pvc

    	NAME         STATUS    VOLUME   CAPACITY   ACCESS MODES   STORAGECLASS          AGE
    	nfs-pvc      Bound     nfs-pv   100Mi      RWX            nfs-pv                83s
   

7. 再次获取pv
   # kubectl get pv

    NAME     CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM             STORAGECLASS   REASON   AGE
   

nfs-pv 100Mi RWX Retain Bound default/nfs-pvc nfs-pv 3m8s

删除pv、pvc

1. 命令
   kubectl delete pvc pvc-name -n namespace
   kubectl delete pv pv-name

   先删除 pvc ，后删除 pv
   如果已经应用到 pod ，那就先删除pod

2. 查询pvc状况
   刚开始创建的 nfs-pvc 一直都是Pending，需要找到原因，学习完之后删除他！
   # kubectl describe pvc nfs-pvc

    Name:          nfs-pvc
    Namespace:     default
    StorageClass:  
    Status:        Pending
    Volume:        
    Labels:        <none>
    Annotations:   <none>
    Finalizers:    [kubernetes.io/pvc-protection]
    Capacity:      
    Access Modes:  
    VolumeMode:    Filesystem
    Used By:       <none>
    Events:
      Type    Reason         Age                   From                         Message
      ----    ------         ----                  ----                         -------
      Normal  FailedBinding  31s (x3927 over 16h)  persistentvolume-controller  no persistent volumes available for this claim and no storage class is set
   

看到错误原因应该是对应的 pv 不存在，因为开始创建的 pv 和 pvc 文件中名称不一致！

3. 回收删除 nfc-pvc
   # kubectl delete -f pvc.yaml

    persistentvolumeclaim "nfs-pvc" deleted
   

4. 验证一下
   # kubectl get pvc

    NAME       STATUS   VOLUME    CAPACITY   ACCESS MODES   STORAGECLASS   AGE
    ...
   

   那个 pending 的 nfs-pvc 删除了！

5. 删除 pv
   # kubectl delete -f pv.yaml

作为练习，复制2 份 pv/pvc 文件

# ls

 pv1.yaml  pv2.yaml  pvc1.yaml  pvc2.yaml  pvc.yaml  pv.yaml

pv1.yaml
# cat pv1.yaml

apiVersion: v1
kind: PersistentVolume
metadata:
  name: nfs-pv1
  namespace: default
  labels:
    pv: nfs-pv1
spec:
  capacity:
    storage: 100Mi
  accessModes:
    - ReadWriteMany
  persistentVolumeReclaimPolicy: Retain
  storageClassName: nfs-pv1
  nfs:  
    server: 192.168.0.141
    path: "/nfs/data/nginx"   #NFS目录，需要该目录在NFS上存在

pvc1.yaml
# cat pvc1.yaml

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: nfs-pvc2
  namespace: default
spec:
  storageClassName: nfs-pv2
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 50Mi  #容量