使用kubectl管理Kubernetes(k8s)集群：常用命令，查看负载，命名空间namespace管理

下载kubens，并授予可执行权限

[root@k8scloude1 ~]# wget https://github.com/ahmetb/kubectx/releases/download/v0.9.4/kubens

[root@k8scloude1 ~]# ll -h kubens 
-rw-r--r-- 1 root root 5.5K 12月  8 15:46 kubens

[root@k8scloude1 ~]# chmod +x kubens 

[root@k8scloude1 ~]# mv kubens /bin/

[root@k8scloude1 ~]# ls /bin/kubens 
/bin/kubens

查看所有的命名空间

[root@k8scloude1 ~]# kubens 
default
kube-node-lease
kube-public
kube-system
ns1
ns2

切换namespace

#切换namespace到kube-system
[root@k8scloude1 ~]# kubens kube-system
Context "kubernetes-admin@kubernetes" modified.
Active namespace is "kube-system".

#此时，默认查询的就是kube-system命名空间下的pod
[root@k8scloude1 ~]# kubectl get pods -o wide
NAME                                       READY   STATUS    RESTARTS   AGE   IP                NODE         NOMINATED NODE   READINESS GATES
calico-kube-controllers-6b9fbfff44-4jzkj   1/1     Running   2          20h   10.244.251.194    k8scloude3              
calico-node-bdlgm                          1/1     Running   1          20h   192.168.110.130   k8scloude1              
calico-node-hx8bk                          1/1     Running   1          20h   192.168.110.128   k8scloude3              
calico-node-nsbfs                          1/1     Running   1          20h   192.168.110.129   k8scloude2              
coredns-545d6fc579-7wm95                   1/1     Running   1          20h   10.244.158.68     k8scloude1              
coredns-545d6fc579-87q8j                   1/1     Running   1          20h   10.244.158.67     k8scloude1              
etcd-k8scloude1                            1/1     Running   1          20h   192.168.110.130   k8scloude1              
kube-apiserver-k8scloude1                  1/1     Running   1          20h   192.168.110.130   k8scloude1              
kube-controller-manager-k8scloude1         1/1     Running   1          20h   192.168.110.130   k8scloude1              
kube-proxy-599xh                           1/1     Running   1          20h   192.168.110.128   k8scloude3              
kube-proxy-lpj8z                           1/1     Running   1          20h   192.168.110.129   k8scloude2              
kube-proxy-zxlk9                           1/1     Running   1          20h   192.168.110.130   k8scloude1              
kube-scheduler-k8scloude1                  1/1     Running   1          20h   192.168.110.130   k8scloude1              
metrics-server-bcfb98c76-k5dmj             1/1     Running   0          56m   10.244.112.131    k8scloude2              

切换namespace到default

#切换namespace到default
[root@k8scloude1 ~]# kubens default
Context "kubernetes-admin@kubernetes" modified.
Active namespace is "default".

#此时，默认查询的就是default命名空间下的pod
[root@k8scloude1 ~]# kubectl get pods -o wide
No resources found in default namespace.

#要查询kube-public命名空间下的pod，使用-n kube-public指定
[root@k8scloude1 ~]# kubectl get pods -n kube-public
No resources found in kube-public namespace.