etcd-backup.sh

#!/bin/bash
# etcd backup and restore — most common exam task
set -euo pipefail

BACKUP_DIR="/tmp/etcd-backups"
BACKUP_FILE="${BACKUP_DIR}/snapshot-$(date +%Y%m%d-%H%M%S).db"

ETCD_CACERT="/etc/kubernetes/pki/etcd/ca.crt"
ETCD_CERT="/etc/kubernetes/pki/etcd/server.crt"
ETCD_KEY="/etc/kubernetes/pki/etcd/server.key"
ETCD_ENDPOINT="https://127.0.0.1:2379"

mkdir -p "$BACKUP_DIR"

case "${1:-backup}" in
  backup)
    echo "Creating etcd snapshot..."
    ETCDCTL_API=3 etcdctl snapshot save "$BACKUP_FILE" \
      --endpoints="$ETCD_ENDPOINT" \
      --cacert="$ETCD_CACERT" \
      --cert="$ETCD_CERT" \
      --key="$ETCD_KEY"

    echo "Verifying snapshot..."
    ETCDCTL_API=3 etcdctl snapshot status "$BACKUP_FILE" --write-table

    echo "Backup saved to: $BACKUP_FILE"
    ;;

  restore)
    RESTORE_FILE="${2:?Usage: $0 restore <snapshot-file>}"
    RESTORE_DIR="/var/lib/etcd-restored"

    echo "Restoring from: $RESTORE_FILE"
    ETCDCTL_API=3 etcdctl snapshot restore "$RESTORE_FILE" \
      --data-dir="$RESTORE_DIR"

    echo "Restored to: $RESTORE_DIR"
    echo ""
    echo "Next steps:"
    echo "  1. Stop kube-apiserver:  mv /etc/kubernetes/manifests/kube-apiserver.yaml /tmp/"
    echo "  2. Update etcd manifest: change --data-dir to $RESTORE_DIR"
    echo "  3. Restart etcd and move kube-apiserver manifest back"
    ;;

  *)
    echo "Usage: $0 {backup|restore <snapshot-file>}"
    exit 1
    ;;
esac