为节点添加flannel.alpha.coreos.com/public-ip-overwrite=<公网ip>注解就行
kubectl annotate nodes dkcjbfrzahrawtduln flannel.alpha.coreos.com/public-ip-overwrite=<公网ip>然后flannel启动的时候就会根据flannel.alpha.coreos.com/public-ip-overwrite=<公网ip>设置flannel.alpha.coreos.com/public-ip