#!/bin/bash

set -eu

usage () {
  echo
  echo Usage: ./backup.sh [-h,  --help]
  echo 
  echo This utility extracts a TAR backup of data and logs
  echo produced by the Taler services running inside this Docker
  echo Compose setup.  The backup is saved in /tmp/YYYY-MM-DD-taler-backup.tar
}

for helpOpt in "-h" "--help"; do
  if test "$helpOpt" = "${1:-}"; then
    usage
    exit 0
  fi
done

if ! which docker > /dev/null; then
  echo docker not found.
  exit 1
fi

BACKUP_FILE="/tmp/$(date +%Y-%m-%d)-taler-backup.tar"

if test -a $BACKUP_FILE; then 
  echo "Backup file $BACKUP_FILE exists already, please move it and run the script again."
  exit 3 
fi

# 'chown' should still help rootful runs to
# have the TAR owned by the user invoking the command.
docker run \
  -v /tmp:/tmp \
  -v demo_talerdata:/taler-data \
  -v demo_talerlogs:/taler-logs \
  -it debian:stable \
  /bin/bash -c "tar --no-same-owner --no-same-permissions -c -f ${BACKUP_FILE} /taler-data /taler-logs" > /dev/null

echo Backup at: ${BACKUP_FILE}