Kubernetes1.8以后版本，kubelet命令去掉--api-servers选项，参考官方kubelet
1.8
--kubeconfig string Path to a kubeconfig file, specifying how to connect to the API server. (default "/var/lib/kubelet/kubeconfig")
1.7
--kubeconfig string Path to a kubeconfig file, specifying how to connect to the API server. --api-servers will be used for the location unless --require-kubeconfig is set. (default "/var/lib/kubelet/kubeconfig")
1.8以后如何配置kubelet连接api-server呢？有两种方法
方法一，使用kubectl config
kubectl config set-cluster kubernetes \--server=http://127.0.0.1:8080
方法二，使用--kubeconfig，修改/etc/kubernetes/kubelet
KUBELET_ARGS="--kubeconfig=/var/lib/kubelet/kubeconfig --cgroup-driver=systemd --fail-swap-on=false"