5.交互式测试客户端及滚动更新、回滚、pod扩缩容

创建一个专用的交互式测试客户端：

拉取镜像
kubectl run client-$RANDOM --image=ikubernetes/admin-box:v1.2 --restart=Never -it --rm --command -- /bin/bash
root@client-12383 /# 

在默认名称空间下的服务去访问另一个名称空间下的服务
查看另一个名称空间
[root@K8s-master01 ~]#kubectl get svc -n demo
NAME        TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)          AGE
demoapp     NodePort    10.102.165.71   <none>        8080:31248/TCP   178m

进行访问：
root@client-12383 /# curl 10.102.165.71:8080
iKubernetes demoapp v1.0 !! ClientIP: 10.244.3.9, ServerName: demoapp-55c5f88dcb-t7xzh, ServerIP: 10.244.4.6!
root@client-12383 /# curl 10.102.165.71:8080
iKubernetes demoapp v1.0 !! ClientIP: 10.244.3.9, ServerName: demoapp-55c5f88dcb-tqb5j, ServerIP: 10.244.5.6!

不在同一名称空间访问要加上名称空间的名字
root@client-12383 /# curl demoapp.demo:8080  （如果端口是80  后面就不用带端口号）
iKubernetes demoapp v1.0 !! ClientIP: 10.244.3.9, ServerName: demoapp-55c5f88dcb-t7xzh, ServerIP: 10.244.4.6!

持续访问命令
root@client-12383 /# while true; do curl demoapp.demo:8080; .5; done

查看pod的详细信息
[root@K8s-master01 ~]#kubectl get pods -n demo
NAME                         READY   STATUS    RESTARTS   AGE
demoapp-55c5f88dcb-t7xzh     1/1     Running   0          3h14m
demoapp-55c5f88dcb-tqb5j     1/1     Running   0          3h14m
mysql-787575d954-cdp4x       1/1     Running   0          3h35m
wordpress-6c854887c8-mwp74   1/1     Running   0          172m

[root@K8s-master01 ~]#kubectl get pods demoapp-55c5f88dcb-t7xzh -n demo -o yaml

镜像升级，不影响服务对外使用（滚动更新机制）

[root@K8s-master01 ~]#kubectl set image deployment demoapp demoapp=ikubernetes/demoapp:v1.1 -n demo
deployment.apps/demoapp image updated

持续访问命令
root@client-12383 /# while true; do curl demoapp.demo:8080; .5; done
由1.0逐渐升级为1.1

应用更新历史

[root@K8s-master01 ~]#kubectl rollout history deploy demoapp -n demo
deployment.apps/demoapp 
REVISION  CHANGE-CAUSE
1         <none>     
2         <none>

回滚应用的更新

[root@K8s-master01 ~]#kubectl rollout undo deployment demoapp -n demo
deployment.apps/demoapp rolled back

持续访问命令
root@client-12383 /# while true; do curl demoapp.demo:8080; .5; done
由1.1逐渐升级为1.0

pod手动扩容或缩容

手动扩容或缩容：
kubectl scale <TYPE>/<NAME> --replicas=<NUM> [-n <NAMESPACE>]
只支持这四种类型
<TYPE> Set a new size for a deployment, replica set, replication controller, or stateful set.
如：kubectl scale deployments/demoapp --replicas=6 -n demo  （扩容）
kubectl scale deployments/demoapp --replicas=4 -n demo  （缩容，不能指定缩哪个）

持续访问命令查看扩容缩容
root@client-12383 /# while true; do curl demoapp.demo:8080; .5; done

使用声明式配置文件-f直接指定目录，会自动把目录下的所有清单文件进行创建

拉取镜像
[root@K8s-master01 tmp]#git clone https://github.com/iKubernetes/learning-k8s.git

[root@K8s-master01 wordpress]#kubectl apply -f mysql-ephemeral/
secret/mysql-user-pass configured
service/mysql unchanged
deployment.apps/mysql configured
没有指定名称空间，就直接配部署在default名称空间下
[root@K8s-master01 wordpress]#kubectl get pods
mysql-787575d954-2l8ns   1/1     Running   0             100s

MySQL的service也被创建出来了 
[root@K8s-master01 wordpress]#kubectl get svc
mysql        ClusterIP   10.98.211.241   <none>        3306/TCP       120s

[root@K8s-master01 wordpress]#kubectl apply -f wordpress-apache-ephemeral/
service/wordpress created
deployment.apps/wordpress created

[root@K8s-master01 wordpress]#kubectl get svc
NAME         TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
kubernetes   ClusterIP   10.96.0.1       <none>        443/TCP        2d11h
mysql        ClusterIP   10.98.211.241   <none>        3306/TCP       2d8h
nginx        NodePort    10.99.87.93     <none>        80:31640/TCP   2d10h
wordpress    NodePort    10.99.203.255   <none>        80:32671/TCP   4m22s

进行访问
http://10.0.0.100:32671/

卸载wordpress、MySQL（清除该目录下所部署的资源一次性清除）只加载yaml、json结尾的文件，其他不做处理
[root@K8s-master01 wordpress]#kubectl delete -f mysql-ephemeral/
secret "mysql-user-pass" deleted
service "mysql" deleted
deployment.apps "mysql" deleted
[root@K8s-master01 wordpress]#kubectl delete -f wordpress-apache-ephemeral/
service "wordpress" deleted
deployment.apps "wordpress" deleted

查看pods（已经没有了相关pods）
[root@K8s-master01 wordpress]#kubectl get pods
NAME                     READY   STATUS    RESTARTS      AGE
client-12383             0/1     Error     0             102m
client-5251              1/1     Running   0             103m
nginx-55f494c486-d442z   1/1     Running   0             107m

连续使用-f选项指定多个目录，同时执行部署操作

[root@K8s-master01 wordpress]#kubectl apply -f mysql-ephemeral/ -f wordpress-apache-ephemeral/
secret/mysql-user-pass created
service/mysql created
deployment.apps/mysql created
service/wordpress created
deployment.apps/wordpress created

[root@K8s-master01 wordpress]#kubectl get pods
NAME                         READY   STATUS    RESTARTS      AGE
client-12383                 0/1     Error     0             106m
client-5251                  1/1     Running   0             107m
mysql-787575d954-2lv4b       1/1     Running   0             18s
wordpress-6c854887c8-vfp9f   1/1     Running   0             18s