@查看master组件状态 kubectl get cs

[root@k8s-master ~]# kubectl get cs
Warning: v1 ComponentStatus is deprecated in v1.19+
NAME                 STATUS    MESSAGE             ERROR
controller-manager   Healthy   ok
scheduler            Healthy   ok
etcd-0               Healthy   {"health":"true"}
[root@k8s-master ~]#

@查看资源 kubectl api-resources
说明：可以查看各个资源的版本，写yaml文件会用到；可以看资源的缩写

[root@k8s-master ~]# kubectl api-resources
NAME                              SHORTNAMES   APIVERSION                             NAMESPACED   KIND
bindings                                       v1                                     true         Binding
componentstatuses                 cs           v1                                     false        ComponentStatus
configmaps                        cm           v1                                     true         ConfigMap
endpoints                         ep           v1                                     true         Endpoints
events                            ev           v1                                     true         Event
limitranges                       limits       v1                                     true         LimitRange
namespaces                        ns           v1                                     false        Namespace
nodes                             no           v1                                     false        Node
persistentvolumeclaims            pvc          v1                                     true         PersistentVolumeClaim
persistentvolumes                 pv           v1                                     false        PersistentVolume
pods                              po           v1                                     true         Pod
……
daemonsets                        ds           apps/v1                                true         DaemonSet
deployments                       deploy       apps/v1                                true         Deployment
……

@查看资源信息，kubectl get --help，kubectl describe --help
kubectl get <resource>
kubectl describe <resource> <name>

kubectl get pods
kubectl get pods -o wide 查看详细信息
kubectl get pods <pod name> 查看具体的pod
kubectl get pods  --show-labels 查看标签
kubectl get pods  -l <key>=<value> 查看具有某标签的pod
kubectl describe pods <pod name> 查看具体pod的详细信息
kubectl get pod,deploy,svc 查看pod,deployment和service

@查看控制平面和集群服务 kubectl cluster-info

[root@k8s-master ~]# kubectl cluster-info
Kubernetes control plane is running at https://192.168.231.121:6443
KubeDNS is running at https://192.168.231.121:6443/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy
Metrics-server is running at https://192.168.231.121:6443/api/v1/namespaces/kube-system/services/https:metrics-server:/proxy

To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.
[root@k8s-master ~]#
[root@k8s-master ~]# kubectl get svc -n kube-system
NAME             TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)                  AGE
kube-dns         ClusterIP   10.96.0.10      <none>        53/UDP,53/TCP,9153/TCP   13d
metrics-server   ClusterIP   10.96.228.107   <none>        443/TCP                  13d
[root@k8s-master ~]#

@查看Node、Pod资源消耗，kubectl top ...
kubectl top nodes
kubectl top node <node name>
kubectl top pods
kubectl top pod <pod name>

[root@k8s-master ~]# kubectl top nodes k8s-node1
NAME        CPU(cores)   CPU%   MEMORY(bytes)   MEMORY%
k8s-node1   62m          3%     773Mi           44%
[root@k8s-master ~]#
[root@k8s-master ~]# kubectl top pods --sort-by=cpu
NAME                         CPU(cores)   MEMORY(bytes)
java-demo-56d54df448-ptww2   2m           162Mi
java-demo-56d54df448-r5rv2   2m           168Mi
java-demo-56d54df448-92n5q   2m           160Mi
nginx-58f8c48d58-48xbn       0m           2Mi
web-96d5df5c8-vjbzv          0m           4Mi
web-96d5df5c8-l5m9f          0m           2Mi
web-96d5df5c8-nqj6z          0m           2Mi
[root@k8s-master ~]# kubectl top pods web-96d5df5c8-nqj6z
NAME                  CPU(cores)   MEMORY(bytes)
web-96d5df5c8-nqj6z   0m           2Mi
[root@k8s-master ~]#

@查看日志
说明: kubeadm部署方式，kubelet是systemd守护进程管理，其它是容器化部署

[root@k8s-master ~]# kubectl get pods -n kube-system
NAME                                      READY   STATUS    RESTARTS   AGE
calico-kube-controllers-97769f7c7-xh7j7   1/1     Running   6          13d
calico-node-58ck4                         1/1     Running   8          13d
calico-node-q6qxm                         1/1     Running   6          13d
calico-node-vmmv5                         1/1     Running   6          13d
coredns-7f89b7bc75-mgtnj                  1/1     Running   6          13d
coredns-7f89b7bc75-wkrjq                  1/1     Running   6          13d
etcd-k8s-master                           1/1     Running   6          13d
kube-apiserver-k8s-master                 1/1     Running   6          13d
kube-controller-manager-k8s-master        1/1     Running   1          34h
kube-proxy-clmzc                          1/1     Running   6          13d
kube-proxy-f4mk4                          1/1     Running   6          13d
kube-proxy-s7n6w                          1/1     Running   6          13d
kube-scheduler-k8s-master                 1/1     Running   1          34h
metrics-server-84f9866fdf-9l6rt           1/1     Running   3          2d
[root@k8s-master ~]#

kubelet => journalctl -u kubelet

kubectl logs <pod name>
kubectl logs -f <pod name>
kubectl logs -f <pod name> -c <container name> 多个容器不指定默认进入第一个

进入容器终端 kubectl exec -it <pod name> -c <container name> -- bash