Quote from moshe on 18/10/2020, 8:35 am

Problem

IP address of Master node changed and now cluster can’t restart

 

Solution

Run the following commands to fix the issue

systemctl stop kubelet docker
cd /etc/
# backup old kubernetes data
mv kubernetes kubernetes-backup
mv /var/lib/kubelet /var/lib/kubelet-backup

# restore certificates
mkdir -p kubernetes
cp -r kubernetes-backup/pki kubernetes
rm kubernetes/pki/{apiserver.*,etcd/peer.*}

systemctl start docker

# reinit master with data in etcd
# add –kubernetes-version, –pod-network-cidr and –token options if needed
kubeadm init –ignore-preflight-errors=DirAvailable–var-lib-etcd

# update kubectl config
cp kubernetes/admin.conf ~/.kube/config

# wait for some time and delete old node
sleep 120
kubectl get nodes –sort-by=.metadata.creationTimestamp
kubectl delete node $(kubectl get nodes -o jsonpath='{.items[?(@.status.conditions[0].status==”Unknown”)].metadata.name}’)

# check running pods
kubectl get pods –all-namespaces

 

Note

This Post was inspired by ticket 338

https://github.com/kubernetes/kubeadm/issues/338