K8-kubelet service failed

-------------journalctl-logs--------------
k8-master-bk kubelet[3878]: k8s.io/kubernetes/vendor/github.com/spf13/cobra.(*Command).execute(0xc0004dab00, 0xc00004e080, 0x6, 0x6, 0xc0004dab00, 0xc00004e080)
k8-master-bk kubelet[3878]: /workspace/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/vendor/github.com/spf13/cobra/command.go:846 +0x2c2
k8-master-bk kubelet[3878]: k8s.io/kubernetes/vendor/github.com/spf13/cobra.(*Command).ExecuteC(0xc0004dab00, 0x170e3addc7846895, 0x6d17d00, 0x409b25)
k8-master-bk kubelet[3878]: /workspace/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/vendor/github.com/spf13/cobra/command.go:950 +0x375
k8-master-bk kubelet[3878]: k8s.io/kubernetes/vendor/github.com/spf13/cobra.(*Command).Execute(...)
k8-master-bk kubelet[3878]: /workspace/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/vendor/github.com/spf13/cobra/command.go:887
k8-master-bk kubelet[3878]: main.main()
k8-master-bk systemd[1]: kubelet.service: main process exited, code=exited, status=255/n/a
k8-master-bk kubelet[3878]: _output/dockerized/go/src/k8s.io/kubernetes/cmd/kubelet/kubelet.go:41 +0xe5

This piece of error output won’t help much.