Kuberbetes Debugging and Tricks

When node needs to be cleared in order to join new/old cluster

Bash

sudo kubeadm reset

sudo apt purge kubectl kubeadm kubelet kubernetes-cni -y
sudo apt autoremove
sudo rm -fr /etc/kubernetes/; sudo rm -fr ~/.kube/; sudo rm -fr /var/lib/etcd; sudo rm -rf /var/lib/cni/

sudo systemctl daemon-reload

sudo iptables -F && sudo iptables -t nat -F && sudo iptables -t mangle -F && sudo iptables -X

Force Removing Namespace

Sometimes they get stuck

Bash

NS=`kubectl get ns |grep Terminating | awk 'NR==1 {print $1}'` && kubectl get namespace "$NS" -o json   | tr -d "\n" | sed "s/\"finalizers\": \[[^]]\+\]/\"finalizers\": []/"   | kubectl replace --raw /api/v1/namespaces/$NS/finalize -f -