yaml for practice, and other things...

sudo daemonize /usr/bin/unshare --fork --pid --mount-proc /lib/systemd/systemd --system-unit=basic.target
exec sudo  nsenter -t $(pidof systemd) -a su - $LOGNAME

The connection to the server localhost:8080 was refused - did you specify the right host or port

check /etc/kubernetes/admin.conf
if have not it , use .kube/config
then:
vi /etc/profile 
add 'export KUBECONFIG=/etc/kubernetes/admin.conf'
source /etc/profile 

some code

kubectl get nodes -o json | jq .items[].metadata.annotations
kubectl get pods -A -o wide | grep coredns

kubectl api-versions
kubectl api-resources
返回GVR信息