Brief analysis Kubernetes Create PV, PVC, Deployment

Brief analysis Kubernetes Create PV, PVC, Deployment

2. Basic Environment

   #系统环境cat /etc/redhat-releaseCentOS Linux release 7.4.1708 (Core)#k8s client 和 server 的版本信息kubectl versionClient Version: version.Info{Major:"1", Minor:"10", GitVersion:"v1.10.0", GitCommit:"fc32d2f3698e36b93322a3465f63a14e9f0eaead", GitTreeState:"clean", BuildDate:"2018-03-26T16:55:54Z", GoVersion:"go1.9.3", Compiler:"gc", Platform:"linux/amd64"}Server Version: version.Info{Major:"1", Minor:"10", GitVersion:"v1.10.1", GitCommit:"d4ab47518836c750f9949b9e0d387f20fb92260b", GitTreeState:"clean", BuildDate:"2018-04-12T14:14:26Z", GoVersion:"go1.9.3", Compiler:"gc", Platform:"linux/amd64"}

4. Order of operations for creating stateful services

   #值得注意的是创建顺序非常关键（1）Volume（2）Persistent Volume（3）Persistent Volume Claim（4）Service（5）StatefulSet

6. Create PV
   I use the NFS service here, click on NFS Deployment and optimization to build your own NFS service.

   #注意两点：（1）请先部署好自己的NFS服务；（2）在使用共享之前，必须运行自己的NFS服务器并运行共享。

   ##持久性存储卷apiVersion: v1kind: PersistentVolumemetadata:name: data-nfs      ##名字任意取labels:   type: nfsspec:capacity:  storage: 8GivolumeMode: FilesystemaccessModes:  - ReadWriteOncepersistentVolumeReclaimPolicy: RecyclemountOptions:  - hard  - nfsvers=4.1nfs:  path: /data  ##NFS服务器上的共享目录  server: 192.168.246.168   ##NFS服务器的ip地址

8. Create PVC

   ##pvc的yamlapiVersion: v1kind: PersistentVolumeClaimmetadata:name: datadir-nginx-0spec:accessModes:  - ReadWriteOnceresources:  requests:    storage: 1Giselector:  matchLabels:    

   #说明：创建PVC的名称和Deployment中的名称要对应上，要不然Deployment中的Pod就肯定创建不成功！简单说一下PVC和Deployment中的命名的规律：如上面创建PVC的yaml文件，我们在这里创建了一个叫做datadir-nginx-0的PVC，粗略一看这个名字有点奇怪，因为这个yaml文件中并没有提到PV的名字，所以PV和PVC是怎么bound起来的呢？是通过labels标签下的type: nfs键值对来进行匹配的，我们在创建PV时指定了label的键值对，在PVC里通过selector可以指定label。关于这个PVC的名称定义：datadir-nginx-0，我们需要看一下下面创建Deployment中的yaml：

9. Create deployment

     Apiversion:apps/v1kind:deploymentmetadata:name:nginx-deploymentlabels:app:nginxspec:replicas: 1selector:matchlabels:app:nginxtemplate:metadata:labels:app:nginx spec:containers:-Name:ngi NX image:nginx:1.7.9 volumemounts:-Mountpath: "/WTF" name:datadir volumes:-Name:dat    Adir persistentvolumeclaim:claimname:datadir-nginx-0 volumeclaimtemplates:-Metadata:name:datadir Labels:type:nfs annotations:volume.alpha.kubernetes.io/storage-class:anything Spec:accessmodes : ["Readwriteonce"] resources:requests:storage:1gi  

   #说明：接着说PVC的名称定义，首先我们看到Deployment的name叫nginx-deployment，设置的replicas为1个，volumeMounts和volumeClaimTemplates的name必须相同，为datadir，所以Deployment创建的第一个Pod的name应该为nginx-0，第二个为nginx-1，依此类推，这里只定义了一个replicas，所以pod的名字是nginx-0。这里Deployment中的Pod与PVC之间的绑定关系是通过名称来匹配的，即：PVC_name === volumeClaimTemplates_name + "-" + pod_name

Brief analysis Kubernetes Create PV, PVC, Deployment