Docker Kubernetes--pod管理（创建，删除，控制器，扩容，暴露端口，更新，回滚）

一、上传镜像到私有仓库

[root@server1 ~]# cd  harbor/
[root@server1 harbor]# docker-compose start
[root@server1 harbor]# docker-compose ps
[root@server1 docker]# docker logout  reg.westos.org
Removing login credentials for reg.westos.org
[root@server1 docker]# docker login  reg.westos.org
[root@server1 harbor]# docker search busyboxplus
[root@server1 harbor]# docker pull rickiechina/busyboxplus
[root@server1 docker]# docker tag rickiechina/busyboxplus:latest reg.westos.org/library/busyboxplus:latest ##改名
[root@server1 docker]# docker push reg.westos.org/library/busyboxplus:latest ##上传

二、pod基本操作

1、创建Pod应用

Pod是可以创建和管理Kubernetes计算的最小可部署单元，一个Pod代表着集群中运行的一个进程，每个pod都有一个唯一的ip。

[root@server2 ~]# kubectl run -h    ##查看创建pod帮助
[root@server2 ~]# kubectl run nginx --image=myapp:v1   ##创建一个pod应用，nginx是名字，myapp是景象
        #--replicas=2   扩容参数  --record   记录参数
        # kubectl run nginx --image=nginx --replicas=2 --record #参数使用方法
[root@server2 ~]# kubectl get pod     ##查看pod
NAME    READY   STATUS    RESTARTS   AGE
nginx   1/1     Running   0          9s
[root@server2 ~]# kubectl get pod -n default    ##查看指定namespace的节点
NAME    READY   STATUS    RESTARTS   AGE
nginx   1/1     Running   0          74s
[root@server2 ~]# kubectl get pod -o wide      ##查看节点的具体信息
NAME    READY   STATUS    RESTARTS   AGE   IP           NODE      NOMINATED NODE   READINESS GATES
nginx   1/1     Running   0          81s   10.244.1.7   server4   <none>           <none>
[root@server2 ~]# curl 10.244.1.7
Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>

[root@server2 ~]# kubectl run demo --image=busyboxplus -it   ##交互式界面运行一个pod,ctrl+p+q退出可以通过kubectl attach demo -c demo -i -t重新进入
[root@server2 ~]# kubectl run demo --image=busyboxplus -it   ##再次进入
#ip addr

[root@server2 ~]# kubectl run demo --image=busyboxplus -it
[root@server2 ~]# kubectl get pod 
NAME    READY   STATUS    RESTARTS   AGE
demo    1/1     Running   0          37s
nginx   1/1     Running   0          14m
[root@server2 ~]# kubectl attach demo -it

2、删除Pod

[root@server2 ~]# kubectl delete pod nginx   ##删除pod
pod "nginx" deleted
[root@server2 ~]# kubectl describe pod demo   ##查看详细描述
[root@server2 ~]# kubectl logs demo     ##查看日志

3、deployment(控制器)

 [root@server2 ~]# kubectl create deployment nginx --image=myapp:v1  ##创建一个pod
  deployment.apps/nginx created         ##生成一个新的deployment控制器的pod，删除之后会自动重新生成不同id的pod
 [root@server2 ~]# kubectl get all
 [root@server2 ~]# kubectl get pod
  NAME                     READY   STATUS    RESTARTS   AGE
  demo                     1/1     Running   0          6m28s
  nginx-67f9d9c97f-xjg2n   1/1     Running   0          28s

 [root@server2 ~]# kubectl delete  pod nginx-67f9d9c97f-xjg2n   ##删除pod后在查看
  pod "nginx-67f9d9c97f-xjg2n" deleted   ##生成新的id的pod
 [root@server2 ~]# kubectl get pod
  NAME                     READY   STATUS    RESTARTS   AGE
  demo                     1/1     Running   0          9m9s
  nginx-67f9d9c97f-bt9k5   1/1     Running   0          116s

 [root@server2 ~]# kubectl delete deployment nginx     ##彻底删除deployment
 [root@server2 ~]# kubectl get pod    ##删除成功

4、Pod扩容与缩容

[root@server2 ~]# kubectl create deployment nginx --image=myapp:v1
deployment.apps/nginx created
[root@server2 ~]# kubectl get pod
NAME                     READY   STATUS    RESTARTS   AGE
demo                     1/1     Running   0          13m
nginx-67f9d9c97f-649gg   1/1     Running   0          3s
[root@server2 ~]# kubectl scale deployment --replicas=2 nginx
deployment.apps/nginx scaled
[root@server2 ~]# kubectl get pod
NAME                     READY   STATUS    RESTARTS   AGE
demo                     1/1     Running   0          13m
nginx-67f9d9c97f-649gg   1/1     Running   0          13s
nginx-67f9d9c97f-sq7qn   1/1     Running   0          6s

[root@server2 ~]# kubectl scale deployment --replicas=4 nginx
deployment.apps/nginx scaled
[root@server2 ~]# kubectl get pod -o wide

5、service微服务

- service是一个抽象概念，定义了一个服务的多个pod逻辑合集和访问pod的策略，一般把service称为微服务。
- 创建service
	$ kubectl expose deployment（控制器） nginx --port=80 --target-port=80
	此时pod客户端可以通过service的名称访问后端的两个Pod
	ClusterIP: 默认类型，自动分配一个仅集群内部可以访问的虚拟IP

ClusterIP默认类型暴露端口

ClusterIP: 默认类型，自动分配一个仅集群内部可以访问的虚拟IP

[root@server2 ~]# kubectl expose deployment nginx --port=80  ##ClusterIP默认类型暴露端口
[root@server2 ~]# kubectl get svc
[root@server2 ~]# curl 10.97.0.120
Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>
[root@server2 ~]# curl 10.97.0.120/hostname.html
nginx-67f9d9c97f-sq7qn
[root@server2 ~]# curl 10.97.0.120/hostname.html
nginx-67f9d9c97f-qd4mp
[root@server2 ~]# curl 10.97.0.120/hostname.html
nginx-67f9d9c97f-sq7qn

[root@server2 ~]# kubectl describe svc nginx      ##查看deployment详细信息 
[root@server2 ~]# kubectl get pod -n kube-system -o wide  ##查看namespace对应的所有pod详细信息
[root@server2 ~]# kubectl scale deployment nginx --replicas=3
[root@server2 ~]# kubectl describe svc nginx

##server3和server4上同样可以访问到对应信息
[root@server3 ~]# curl 10.97.0.120/hostname.html 
[root@server4 ~]# curl 10.97.0.120/hostname.html

NodePort类型暴露端口

 使用NodePort类型暴露端口，让外部客户端访问Pod(即真机也可以访问)
	$ kubectl edit svc nginx		//修改service的type为NodePort
	$ kubectl expose deployment nginx --port=80 --target-port=80 --type=NodePort		//也可以在创建service时指定类型
	NodePort: 在ClusterIP基础上为Service在每台机器上绑定一个端口，这样就可以通过  NodeIP:NodePort 来访问该服务

[root@server2 ~]# kubectl get svc     ##查看TYPE
NAME         TYPE        CLUSTER-IP    EXTERNAL-IP   PORT(S)   AGE
kubernetes   ClusterIP   10.96.0.1     <none>        443/TCP   27d
nginx        ClusterIP   10.97.0.120   <none>        80/TCP    9m54s
[root@server2 ~]# kubectl edit svc nginx  ##TYPE改成NodePort
service/nginx edited
[root@server2 ~]# kubectl get svc     ##80映射31572端口
NAME         TYPE        CLUSTER-IP    EXTERNAL-IP   PORT(S)        AGE
kubernetes   ClusterIP   10.96.0.1     <none>        443/TCP        27d
nginx        NodePort    10.97.0.120   <none>        80:31572/TCP   10m

6、更新pod镜像

[root@server2 ~]# kubectl set image deployment nginx myapp=myapp:v2  ##更新到v2
[root@server2 ~]# kubectl rollout history deployment nginx    ##查看更新记录
[root@server2 ~]# kubectl describe deployments.apps nginx 

[root@foundation50 Desktop]# curl 192.168.0.2:31572
Hello MyApp | Version: v2 | <a href="hostname.html">Pod Name</a>

7、回滚

[root@server2 ~]# kubectl get pod  ##rs值变成版本2的rs值
[root@server2 ~]# kubectl rollout undo deployment nginx --to-revision=1  //回滚版本
deployment.apps/nginx rolled back
[root@server2 ~]# kubectl rollout history deployment nginx  //查看历史版本
deployment.apps/nginx 
REVISION  CHANGE-CAUSE
2         <none>
3         <none>
[root@foundation50 Desktop]# curl 192.168.0.2:31572
Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>
[root@server2 ~]# kubectl get pod ##rs值变成版本1的rs值