09-Practice-Test-Backup-and-Restore-Methods.md

Practice Test - Backup and Restore Methods

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Solutions to practice test - Backup and Restore Methods

1. How many deployments exist in the cluster?

   kubectl get deployments
   

2. What is the version of ETCD running on the cluster?

   kubectl describe pod -n kube-system etcd-controlplane
   

   Find the entry for Image

3. At what address can you reach the ETCD cluster from the controlplane node?

   kubectl describe pod -n kube-system etcd-controlplane
   

   Under Command find --listen-client-urls

4. Where is the ETCD server certificate file located?

   On kubeadm clusters like this one, the default location for certificate files is /etc/kubernetes/pki/etcd

   Choose the correct certificate

5. Where is the ETCD CA Certificate file located?

   On kubeadm clusters like this one, the default location for certificate files is /etc/kubernetes/pki/etcd

   Choose the correct certificate

6. Take a snapshot of the ETCD database using the built-in snapshot functionality.
   Store the backup file at location /opt/snapshot-pre-boot.db

   ETCDCTL_API=3 etcdctl snapshot save \
     --cacert=/etc/kubernetes/pki/etcd/ca.crt \
     --cert=/etc/kubernetes/pki/etcd/server.crt \
     --key=/etc/kubernetes/pki/etcd/server.key \
     /opt/snapshot-pre-boot.db
   

7. Information only.

8. Wake up! We have a conference call! After the reboot the master nodes came back online, but none of our applications are accessible. Check the status of the applications on the cluster. What's wrong?

   All of the above

9. Luckily we took a backup. Restore the original state of the cluster using the backup file.

   1. Restore the backup to a new directory

      ETCDCTL_API=3 etcdctl snapshot restore \
        --data-dir /var/lib/etcd-from-backup \
        /opt/snapshot-pre-boot.db
      

   2. Modify the etcd pod to use the new directory.

      To do this, we need to edit the volumes section and change the hostPath to be the directory we restored to.

      vi /etc/kubernetes/manifests/etcd.yaml
      

        volumes:
        - hostPath:
            path: /etc/kubernetes/pki/etcd
            type: DirectoryOrCreate
          name: etcd-certs
        - hostPath:
            path: /var/lib/etcd      # <- change this
            type: DirectoryOrCreate
          name: etcd-data

      New value: /var/lib/etcd-from-backup

      Save this and wait for up to a minute for the etcd pod to reload.

   3. Verify

      kubectl get deployments
      kubectl get services
      

See also: https://github.com/kodekloudhub/community-faq/blob/main/docs/etcd-faq.md