I have below question on killercoda for CKA certification
Question:
For this question, please set this context (In exam, diff cluster name)

kubectl config use-context kubernetes-admin@kubernetes

etcd-controlplane pod is running in kube-system environment, take backup and store it in /opt/cluster_backup.db file.

ETCD backup is stored at the path /opt/cluster_backup.db on the controlplane node. for –data-dir use /root/default.etcd , restore it on the controlplane node itself and , and also store restore console output store it in restore.txt

ssh controlplane

Answer:

I ran below commands

ETCDCTL_API=3 etcdctl --endpoints=https://127.0.0.1:2379 
  --cacert=/etc/kubernetes/pki/etcd/ca.crt --cert=/etc/kubernetes/pki/etcd/server.crt --key=/etc/kubernetes/pki/etcd/server.key 
  snapshot save /opt/cluster_backup.db

After running export

ETCDCTL_API=3
etcdctl --write-out=table snapshot status /opt/cluster_backup.db

I am getting as in screenshotoutput of backup

ETCDCTL_API=3 etcdctl --data-dir=/root/default.etcd --endpoints=https://127.0.0.1:2379 
  --cacert=/etc/kubernetes/pki/etcd/ca.crt --cert=/etc/kubernetes/pki/etcd/server.crt --key=/etc/kubernetes/pki/etcd/server.key 
  snapshot restore /opt/cluster_backup.db > restore.txt

But when I run cat restore.txt, I am not getting anything.