Backing up and Restoring Kubernetes Data in etcd

Introduction

Backups are an important part of any resilient system. Kubernetes is no exception. In this lab, you will have the opportunity to practice your skills by backing up and restoring a Kubernetes cluster state stored in etcd. This will help you get comfortable with the steps involved in backing up Kubernetes data.

Learning Objectives

Back Up the etcd Data

Restore the etcd Data from the Backup

Solution

Log in to the provided lab server using the credentials provided:

ssh <user>@<IP_ADDRESS>

Back Up the etcd Data

1. Look up the value for the key cluster.name in the etcd cluster:
   • ETCDCTL_API=3 etcdctl get cluster.name \
   • --endpoints=https://10.0.1.101:2379 \
   • --cacert=/home/cloud_user/etcd-certs/etcd-ca.pem \
   • --cert=/home/cloud_user/etcd-certs/etcd-server.crt \
   • --key=/home/cloud_user/etcd-certs/etcd-server.key
2. The returned value should be your Clustername.
3. Back up etcd using etcdctl and the provided etcd certificates:
   • ETCDCTL_API=3 etcdctl snapshot save /home/cloud_user/etcd_backup.db \
   • --endpoints=https://10.0.1.101:2379 \
   • --cacert=/home/cloud_user/etcd-certs/etcd-ca.pem \
   • --cert=/home/cloud_user/etcd-certs/etcd-server.crt \
   • --key=/home/cloud_user/etcd-certs/etcd-server.key
4. Reset etcd by removing all existing etcd data:
   • sudo systemctl stop etcd sudo rm -rf /var/lib/etcd

Restore the etcd Data from the Backup

1. Restore the etcd data from the backup (this command spins up a temporary etcd cluster, saving the data from the backup file to a new data directory in the same location where the previous data directory was):
   • sudo ETCDCTL_API=3 etcdctl snapshot restore /home/cloud_user/etcd_backup.db \
   • --initial-cluster etcd-restore=https://10.0.1.101:2380 \
   • --initial-advertise-peer-urls https://10.0.1.101:2380 \
   • --name etcd-restore \ --data-dir /var/lib/etcd
2. Set ownership on the new data directory:
   • sudo chown -R etcd:etcd /var/lib/etcd
3. Start etcd:
   • sudo systemctl start etcd
4. Verify the restored data is present by looking up the value for the key cluster.name again:
   • ETCDCTL_API=3 etcdctl get cluster.name \
   • --endpoints=https://10.0.1.101:2379 \
   • --cacert=/home/cloud_user/etcd-certs/etcd-ca.pem \
   • --cert=/home/cloud_user/etcd-certs/etcd-server.crt \
   • --key=/home/cloud_user/etcd-certs/etcd-server.key
5. The returned value should be Clustername as noted before.