kubetl命令行管理工具

Posted 2021-10-26 水木，年華

Kubectl是管理k8s集群的命令行工具，通过生成的json格式传递给apiserver进行创建、查看、管理的操作。

//帮助信息

[root@master ~]# kubectl --help

查看名称空间资源信息

[root@master ~]#  kubectl get pods,svc --all-namespaces -o wide  以长格式显示详细信息

//项目的生命周期，创建–》发布–》更新–》回滚–》删除
//创建 kubectl run命令

[root@master ~]# kubectl run nginx-deployment --image=nginx --port=80 --replicas=3

[root@master ~]# kubectl get all  #以短格式显示除核心组件之外的信息

基于pod删除

[root@master ~]# kubectl delete pod nginx-deployment-8859878f8-7tctf -n default 
[root@master k8s]# kubectl delete  pod nginx-5ff9d6cc77-k5k5x --force --grace-period=0  -n default   强制删除

基于控制器删除

[root@master ~]# kubectl delete deploy/nginx-deployment 

//项目周期
1：创建nginx

[root@master ~]# kubectl run nginx --image=nginx:latest --port=80 --replicas=3

查询

[root@master ~]# kubectl get pods,deployment

2：发布nginx service提供负载均衡的功能

[root@master ~]# kubectl expose deployment nginx --port=80 --target-port=80 --name=nginx-service --type=NodePort
# --port为pod的端口，--target-port为service的端口，30215为对外服务的端口

//查看资源对象简写

[root@master ~]#  kubectl api-resources

//查看关联后端的节点

[root@master ~]#  kubectl get endpoints
NAME            ENDPOINTS                                   AGE
kubernetes      192.168.80.1:6443                           15h
nginx-service   10.244.1.3:80,10.244.2.5:80,10.244.2.6:80   9m5s
[root@master ~]# kubectl get ep --all-namespaces       #可以查看IP地址，节点信息
NAMESPACE     NAME                      ENDPOINTS                                               AGE
default       kubernetes                192.168.80.1:6443                                       7d1h
default       nginx-service             10.244.2.5:80,10.244.2.6:80                             6d10h
kube-system   kube-controller-manager   <none>                                                  7d1h
kube-system   kube-dns                  10.244.0.6:53,10.244.0.7:53,10.244.0.6:53 + 3 more...   7d1h
kube-system   kube-scheduler            <none>                                                  7d1h

//查看具体资源的详细信息

[root@master ~]# kubectl get pods 
NAME                     READY   STATUS        RESTARTS   AGE
nginx-5ff9d6cc77-k5k5x   1/1     Terminating   0          6d11h
nginx-5ff9d6cc77-p9v2j   1/1     Running       0          6d11h
nginx-5ff9d6cc77-w75cs   1/1     Running       0          46m
nginx-5ff9d6cc77-wnh2g   1/1     Running       0          6d11h

[root@master ~]# kubectl describe pod nginx-5ff9d6cc77-k5k5x
Name:                      nginx-5ff9d6cc77-k5k5x
Namespace:                 default
Priority:                  0
Node:                      node1/192.168.80.2
Start Time:                Thu, 30 Sep 2021 10:18:29 +0800
Labels:                    pod-template-hash=5ff9d6cc77
                           run=nginx
Annotations:               <none>
Status:                    Terminating (lasts 49m)
Termination Grace Period:  30s
IP:                        10.244.1.3
Controlled By:             ReplicaSet/nginx-5ff9d6cc77
Containers:
  nginx:
    Container ID:   docker://95b86265905ed148f40d749b767dcfbd859b6d1240f2b2388f2500470439f872
    Image:          nginx:latest
    Image ID:       docker-pullable://nginx@sha256:969419c0b7b0a5f40a4d666ad227360de5874930a2b228a7c11e15dedbc6e092
    Port:           80/TCP
    Host Port:      0/TCP
    State:          Running
      Started:      Thu, 30 Sep 2021 10:18:46 +0800
    Ready:          True
    Restart Count:  0
    Environment:    <none>
    Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from default-token-4mdv8 (ro)
Conditions:
  Type              Status
  Initialized       True 
  Ready             False 
  ContainersReady   True 
  PodScheduled      True 
Volumes:
  default-token-4mdv8:
    Type:        Secret (a volume populated by a Secret)
    SecretName:  default-token-4mdv8
    Optional:    false
QoS Class:       BestEffort
Node-Selectors:  <none>
Tolerations:     node.kubernetes.io/not-ready:NoExecute for 300s
                 node.kubernetes.io/unreachable:NoExecute for 300s
Events:          <none>

查看节点日志

[root@master ~]# kubectl logs -f nginx-5ff9d6cc77-p9v2j  -n default

//获取修改模板

[root@master k8s]# kubectl edit pod nginx-deployment-8859878f8-jpxqk  -n default 
#修改配置文件

[root@master k8s]# kubectl set image deploy/nginx nginx=nginx:1.14 
#修改镜像版本

[root@master k8s]# kubectl describe po nginx-7485bf6f9b-x7hq2 -n default 
#查看描述性信息

//处于动态监听状态

[root@master k8s]#  kubectl get pods -w
NAME                     READY   STATUS    RESTARTS   AGE
nginx-7485bf6f9b-x7hq2   1/1     Running   0          12m

4：回滚nginx

[root@master k8s]# kubectl rollout --help 

Manage the rollout of a resource.
  
 Valid resource types include:

  *  deployments
  *  daemonsets
  *  statefulsets

Examples:
  # Rollback to the previous deployment
  kubectl rollout undo deployment/abc
  
  # Check the rollout status of a daemonset
  kubectl rollout status daemonset/foo

Available Commands:
  history     显示 rollout 历史
  pause       标记提供的 resource 为中止状态
  restart     Restart a resource
  resume      继续一个停止的 resource
  status      显示 rollout 的状态
  undo        撤销上一次的 rollout

Usage:
  kubectl rollout SUBCOMMAND [options]

Use "kubectl <command> --help" for more information about a given command.
Use "kubectl options" for a list of global command-line options (applies to all commands).

//查看历史版本

[root@master k8s]# kubectl rollout history deployment/nginx 
deployment.extensions/nginx 
REVISION  CHANGE-CAUSE
1         <none>
2         <none>

//执行回滚

[root@master k8s]# kubectl rollout undo deployment/nginx 
deployment.extensions/nginx rolled back

//检查回滚状态

[root@master k8s]# kubectl rollout status deployment/nginx 
deployment "nginx" successfully rolled out

[root@master k8s]# kubectl describe po nginx-5ff9d6cc77-wgfm4  -n default 

//删除nginx

查看deployment
[root@master k8s]# kubectl get deploy 
NAME    READY   UP-TO-DATE   AVAILABLE   AGE
nginx   1/1     1            1           44m
删除deployment
[root@master k8s]# kubectl delete deployment/nginx 
deployment.extensions "nginx" deleted
[root@master k8s]# kubectl get deploy
No resources found.
[root@master k8s]# kubectl get pods
No resources found.

//删除服务SVC

[root@localhost bin]# kubectl get svc
NAME            TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)        AGE
kubernetes      ClusterIP   10.0.0.1     <none>        443/TCP        12d
nginx-service   NodePort    10.0.0.247   <none>        80:38804/TCP   114m
[root@localhost bin]# kubectl delete svc/nginx-service
service "nginx-service" deleted
[root@localhost bin]# kubectl get svc
NAME         TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
kubernetes   ClusterIP   10.0.0.1     <none>        443/TCP   12d

//进入pod

[root@master k8s]# kubectl exec -it nginx-deployment-8859878f8-4hjnh bash 
root@nginx-deployment-8859878f8-4hjnh:/# ls 
bin  boot  dev	docker-entrypoint.d  docker-entrypoint.sh  etc	home  lib  lib64  media  mnt  opt  proc  root  run  sbin  srv  sys  tmp  usr  var
root@nginx-deployment-8859878f8-4hjnh:/# pwd 
/