where I can find kubeadm-config.yaml on my kubernetes cluster

Question

There is a k8s single master node, I need to back it up and restore it I googled this topic and found a solution - https://elastisys.com/2018/12/10/backup-kubernetes-how-and-why/

Everything looked easy; so,I followed the instruction and got a copy of the certificates and a snapshot of the etcd database.

But at last, I am not able to find kubeadm-config.yaml on my master server.

Where to find this file?

Lunulate

Answer 1

During kubeadm init, kubeadm uploads the ClusterConfiguration object to your cluster in a ConfigMap called kubeadm-config in the kube-system namespace. You can get it from the ConfigMap and take a backup

kubectl get cm kubeadm-config  -n kube-system -o yaml > kubeadm-config.yaml

https://kubernetes.io/docs/reference/setup-tools/kubeadm/kubeadm-config/

Ferricyanide

thanks, I got the kubeadm-config.yaml but when I restore my master I got no no InitConfiguration or ClusterConfiguration kind was found in the YAML file – Lunulate

Initialize the master with backup sudo kubeadm init --ignore-preflight-errors=DirAvailable--var-lib-etcd \ --config /etc/kubeadm/kubeadm-config.yaml – Lunulate

share the yaml file in your question – Ferricyanide

this is the Configmap data which need to be reformatted into the actual config file before using it for kubeadm init – Ferricyanide

make sure to upload the latest updates : kubeadm config upload from-file – Larondalarosa