code:

#!/usr/bin/env bash

set -x
set -e

RESTORE_FROM_HOSTNAME=$1
if [ -z "$RESTORE_FROM_HOSTNAME" ]; then
  echo "You must specify RESTORE_FROM_HOSTNAME environment variable, exiting"
  exit 1
fi

DAYZ_DATA_DIR=/home/dayzserver/serverfiles/mpmissions
INDICATOR_FILE=$DAYZ_DATA_DIR/dayzOffline.chernarusplus/my-dayz-data-indicator

if [ -f "$INDICATOR_FILE" ]; then
  echo "$INDICATOR_FILE already exists, the data in the docker volume is the live server data"
else
  echo "$INDICATOR_FILE does not exist, the data in the docker volume IS NOT the live server data"
  echo "Checking to see if a backup exists to restore for $RESTORE_FROM_HOSTNAME"
  MOST_RECENT_BACKUP=$(aws s3 ls s3://my-cool-bucket/$RESTORE_FROM_HOSTNAME/dayz/ | sort | tail -n 1 | awk '{print $4}')
  if [ -z "$MOST_RECENT_BACKUP" ]; then
    echo "No backup found! Seeding backup from initial DayZ install"
    BACKUP_FILENAME="dayz_$(date "+%Y%m%d.%H%M%S").tar.gz"
    tar czf /tmp/$BACKUP_FILENAME -C $DAYZ_DATA_DIR .
    aws s3 cp --quiet --no-progress /tmp/$BACKUP_FILENAME s3://my-cool-bucket/$RESTORE_FROM_HOSTNAME/dayz/
    rm /tmp/$BACKUP_FILENAME
  else
    echo "Backup found! Restoring backup from $MOST_RECENT_BACKUP"
    echo "Clearing existing directory $DAYZ_DATA_DIR"
    rm -rf $DAYZ_DATA_DIR/*
    aws s3 cp s3://my-cool-bucket/$RESTORE_FROM_HOSTNAME/dayz/$MOST_RECENT_BACKUP /tmp/$MOST_RECENT_BACKUP
    tar xvzf /tmp/$MOST_RECENT_BACKUP -C $DAYZ_DATA_DIR
    rm /tmp/$MOST_RECENT_BACKUP
  fi
  echo "Creating $INDICATOR_FILE"
  touch $INDICATOR_FILE
fi