Kubernetes集群之熟悉kubectl基础命令

王先森2021-09-262021-09-26

管理K8S资源的三种基本方法

陈述式管理方法——命令行CLI工具
声明式管理方法——统一资源配置清单(mainfest)
GUI式管理方法——web页面(dashboard)

kubectl命令行

kubernetes集群管理集群资源的唯一入口式通过相应的方法调用apiserver的接口
kubectl是官方的CLI命令行工具，用于与apiserver进行通信，将用户在命令行输入的命令，组织并转化为apiserver能识别的信息，进而实现管理K8S各种资源的一种有效途径

陈述式资源管理方法

基础管理

查看名称空间

1 2	kubectl get namespaces kubectl get ns

查看名称空间内的资源

1	kubectl get all [-n default]

创建名称空间

1 2	kubectl create namespaces app_name kubectl create ns app_name

删除名称空间

1 2	kubectl delete namespaces app_name kubectl delete ns app_name

创建deployment

1	kubectl create deployment nginx-dp --image=harbor.od.com/public/nginx:v1.15.2 -n kube-public

查看deployment

1 2	kubectl get deployments -n kube-public -o wide kubectl get deploy -n kube-public -o wide

详细查看

1	kubectl describe deployment nginx-dp -n kube-public

查看pod资源

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kubectl get pods -A   # 查看所有pod资源
kubectl get pods -o wide # 查看pod详细信息
kubectl get pods --show-labels  # 查看pod标签

进入pod资源

1	kubectl exec -it -n kube-public nginx-dp-5dfc645654-3jsg5 -- /bin/bash

缩放副本数

1 2	kubectl scale deploy nginx-dp --replicas=2 -n kube-public kubecrl edit depoly nginx-dp

删除pod资源（重启）

1	kubectl delete pod -n kube-public nginx-dp-5dfc689474-4vgz9 [--force --grace-period=0]

删除deployment

1	kubectl delete deployment -n kube-public nginx-dp

node打标签

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kubectl label node k8s-master1.boysec.cn node-role.kubernetes.io/slave=
# 删除
kubectl label node k8s-master1.boysec.cn node-role.kubernetes.io/slave-

pod打标签

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kubectl label pod nginx-55d498bc69-6kwg4 hello=666
# 删除
kubectl label pod nginx-55d498bc69-6kwg4 hello-

Service资源管理

ClusterIP

# 创建容器
kubectl create deploy nginx --image=harbor.od.com/public/nginx:v1
# 增加
kubectl scale deploy nginx --replicas=3

# 查看标签
[root@k8s-master1 ~]# kubectl get pod --show-labels
NAME                     READY   STATUS    RESTARTS   AGE     LABELS
nginx-55d498bc69-6kwg4   1/1     Running   0          2m3s    app=nginx,pod-template-hash=55d498bc69
nginx-55d498bc69-mdm88   1/1     Running   0          4m16s   app=nginx,pod-template-hash=55d498bc69
nginx-55d498bc69-skrm7   1/1     Running   0          2m3s    app=nginx,pod-template-hash=55d498bc69

# 暴露nginx服务
[root@k8s-master1 ~]# kubectl expose deploy nginx --port=8888 --target-port=80
service/nginx exposed

# 查看svc
[root@k8s-master1 ~]# kubectl get svc
NAME         TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)    AGE
nginx        ClusterIP   192.168.1.211   <none>        8888/TCP   16
[root@k8s-master1 ~]# curl 192.168.1.211:8888

NodePort

[root@k8s-master1 ~]# kubectl expose deploy nginx --port=8888 --target-port=80 --type=NodePort
[root@k8s-master1 ~]# kubectl get svc nginx      
NAME    TYPE       CLUSTER-IP        EXTERNAL-IP   PORT(S)          AGE
nginx   NodePort   192.168.139.106   <none>        8888:16269/TCP   27s

注意：集群外通过外部IP+16269端口访问，集群内通过8888端口访问

滚动升级

# 应用升级：nginx:v1.12 \nginx:v1.15
# kubectl set image deployment/nginx busybox=busybox nginx=nginx:1.9.1

 kubectl set image deploy/nginx nginx=harbor.od.com/public/nginx:v2
# 可以携带--record参数记录变更。

回滚记录

[root@k8s-master1 ~]# kubectl rollout history deploy/nginx
deployment.apps/nginx 
REVISION  CHANGE-CAUSE
1         <none>
2         <none>
3         kubectl set image deploy/nginx nginx=harbor.od.com/public/nginx:v3 --record=true