参考:
[Kubernetes]node节点pod无法启动/节点删除网络重置
kubeadm reset
systemctl stop kubelet
systemctl stop docker
ifconfig cni0 down
ifconfig flannel.1 down
ifconfig del flannel.1
ifconfig del cni0
ip link del flannel.1
ip link del cni0
yum install bridge-utils
brctl delbr flannel.1
brctl delbr cni0
rm -rf /var/lib/cni/flannel/* && rm -rf /var/lib/cni/networks/cbr0/* && ip link delete cni0 && rm -rf /var/lib/cni/network/cni0/*