root@ubuntu:~# kubectl delete -f kube-flannel.yml 
podsecuritypolicy.policy "psp.flannel.unprivileged" deleted
clusterrole.rbac.authorization.k8s.io "flannel" deleted
clusterrolebinding.rbac.authorization.k8s.io "flannel" deleted
serviceaccount "flannel" deleted
configmap "kube-flannel-cfg" deleted
daemonset.apps 
 
"kube-flannel-ds-amd64" deleted
daemonset.apps "kube-flannel-ds-arm64" deleted
daemonset.apps "kube-flannel-ds-arm" deleted
daemonset.apps "kube-flannel-ds-ppc64le" deleted
daemonset.apps "kube-flannel-ds-s390x" deleted

#第二步，在node節點清理flannel網路留下的檔案
ifconfig cni0 down
ip link delete cni0
ifconfig flannel.
 
1 down
ip link delete flannel.1
rm -rf /var/lib/cni/
rm -f /etc/cni/net.d/*

root@cloud:~# ifconfig cni0 down
root@cloud:~# ip link delete cni0
root@cloud:~# ifconfig flannel.1 down
root@cloud:~# ip link delete flannel.1
root@cloud:~# rm -rf /var/lib/cni/
root@cloud:~# rm -f /etc/cni/net.d/*
root@cloud:~#