Pod和Namespace的基本介绍

Posted 2021-12-07 yxh168

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namespace资源名称空间

删除namespace资源会级联删除其所包含的所有其它资源对象
名称空间仅仅只是用来限制资源名称的作用域并不能实现Pod的通信隔离

在名称空间下操作service 实现service资源隔离
 [[email protected]-master ~]# kubectl create service nodeport my-ns --tcp=5678:8080 -n qa
service/my-ns created
[[email protected]-master ~]# kubectl get svc
NAME         TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
kubernetes   ClusterIP   10.96.0.1        <none>        443/TCP        231d
myapp        NodePort    10.100.165.177   <none>        80:32185/TCP   21h
[[email protected]-master ~]# kubectl get svc -n default
NAME         TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
kubernetes   ClusterIP   10.96.0.1        <none>        443/TCP        231d
myapp        NodePort    10.100.165.177   <none>        80:32185/TCP   21h
[[email protected]-master ~]# kubectl get svc -n qa
NAME      TYPE       CLUSTER-IP     EXTERNAL-IP   PORT(S)          AGE
my-ns     NodePort   10.102.116.9   <none>        5678:30170/TCP   24s

[[email protected]-master ~]# kubectl delete svc my-ns
Error from server (NotFound): services "my-ns" not found
[[email protected]-master ~]# kubectl delete svc my-ns -n qa
service "my-ns" deleted
[[email protected]-master ~]# kubectl delete all --all -n qa
service "my-ns" deleted

名称空间

[[email protected] ~]# kubectl get svc
NAME         TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
kubernetes   ClusterIP   10.96.0.1        <none>        443/TCP        230d
myapp        NodePort    10.100.165.177   <none>        80:32185/TCP   5m
[[email protected]-master ~]# kubectl run client --image=busybox --restart=Never -it /bin/sh
If you don‘t see a command prompt, try pressing enter.
/ # wget -O -q http://myapp.default:80
Connecting to myapp.default:80 (10.100.165.177:80)
-q                   100% |*****************************************|    65  0:00:00 ETA
/ # wget -O  - -q http://myapp.default:80
Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>
/ # wget -O  - -q http://myapp.default:80
Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>

[[email protected]-master ~]# wget -O - -q http://myappd.default:80/hostname.html
[[email protected] ~]# kubectl get pods
NAME                     READY     STATUS    RESTARTS   AGE
client                   1/1       Running   0          46m
myapp-6865459dff-c59qp   1/1       Running   0          1h
myapp-6865459dff-zd6wg   1/1       Running   0          10m
[[email protected]-master ~]# kubectl exec -it client /bin/sh
/ # wget -O - -q http://myapp.default:80/hostname.html
myapp-6865459dff-zd6wg

pod和pods deployment和deployments都可以
[[email protected]-master ~]# kubectl get deployment
NAME      DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
myapp     2         2         2            2           1h
[[email protected]-master ~]# kubectl get deployments
NAME      DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
myapp     2         2         2 


kubectl打补丁包
[[email protected]-master ~]# kubectl patch deployment myapp-deploy -p ‘{"spec":{"strategy":{"rollingUpdate":{"maxSurge":1,"maxUnavailable":0}}}}‘
deployment.extensions/myapp-deploy patched

[[email protected]-master ~]# kubectl set image deployment myapp-deploy myapp=ikubernetes:v3 && kubectl rollout pause deployment myapp-deploy
deployment.extensions/myapp-deploy image updated
deployment.extensions/myapp-deploy paused

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pod介绍

pod的种类

1.自主式pod
自主式pod在非正常结束的情况下无法自动重新启动一个新的Pod

2.受控Pod
由控制器管理启动的Pod在异常退出的时候控制器会自动创建新Pod

1.pod存活性探测
存活性探测一旦检测到异常就会不断的重启容器直到服务恢复正常
2.pod就绪性探测
探测失败后不会杀死或者重启容器而是通知其尚未就绪并触发依赖于其就绪状态的操作如从Service中移除此pod对象
就绪性探测和service把用户请求调度到pod上有着重要的关系

 3.httpGet
    livenessProbe:
      httpGet:
        path: /healthz
        port: 80
        scheme: HTTP
 4.execAction
    livenessProbe:
      exec:
        command: ["test","-e","/tmp/healthy"]
 5.TcpSocket
    livenessProbe:
      tcpSocket:
        port: 80
 6.pod生命周期钩子函数
    lifecycle:
      postStart:
        exec:
          command: ["/bin/sh","-c","echo ‘lifecycle hooks handler ‘ > /usr/share/nginx/html/test.html"]