Script for Turris Omnia routers creates a schnapps snapshot, exports it, saves it to /srv/backup

snapshot_turris_omnia.sh

#!/bin/bash

set -e

LOGGER_TAG="cron-auto-snapshot"
DESCRIPTION="Auto snapshot $TIMESTAMP by cron"
TIMESTAMP=$(date +"%Y-%m-%d_%H-%M-%S")
BACKUP_DIR="/srv/backups/"
MAX_BACKUPS=5

if [ ! -d "$BACKUP_DIR" ]; then
  mkdir -p "$BACKUP_DIR" || { logger "ERROR: Failed to create the directory."; exit 1; }
fi

SNAPSHOT_ID=$(schnapps create "$DESCRIPTION" | awk '/Snapshot number/ {print $3}')

if [ -z "$SNAPSHOT_ID" ]; then
  logger -t ${LOGGER_TAG} "ERROR: Failed to create the snapshot."
  exit 1
fi

logger -t ${LOGGER_TAG} "Snapshot created: ID $SNAPSHOT_ID"

EXPORT_FILE="${BACKUP_DIR}/omnia-medkit-turris-${SNAPSHOT_ID}.tar.gz"

schnapps export "$SNAPSHOT_ID" "$BACKUP_DIR"

if [ ! -f "$EXPORT_FILE" ]; then
  logger -t ${LOGGER_TAG} "ERROR: Snapshot export failed.."
  exit 1
fi

logger -t ${LOGGER_TAG} "snapshot finshed"

BACKUP_FILES=($(ls -1t "${BACKUP_DIR}"/omnia-medkit-turris-*.tar.gz 2>/dev/null))
NUM_BACKUPS=${#BACKUP_FILES[@]}

if (( NUM_BACKUPS > MAX_BACKUPS )); then
  TO_DELETE=("${BACKUP_FILES[@]:$MAX_BACKUPS}")
  for f in "${TO_DELETE[@]}"; do
    logger -t ${LOGGER_TAG} "Removing old snapshot: $f"
    rm -f "$f"
  done
fi