backup.sh

#!/bin/bash
# Author: [email protected]

# attempt at decent backup script
# Some inspiration drawn from http://wiki.canarymod.net/Install_Canary


INSTANCE="tk_prod"
SESSION_NAME="tk_prod"
USER="tk_prod"
ME=`whoami`

as_user() {
  if [ "$ME" == "$USERNAME" ] ; then
    bash -c "$1"
  else
    su - $USERNAME -c "$1"
  fi
}

server_command() {
    sudo -u ${USER} screen -p 0 -S ${SESSION_NAME} -X eval "stuff '$1'\015"
}

server_announce() {
    server_command "say $1"
}

# detect screen of correct minecraft instance

# message about imminent backup
#server_announce "§7Server snapshot backup starting, going read-only..."
echo "Notified players..."

# autosave off, so no random stuff gets saved too soon after the explicit save ans stuff gets inconsistent
server_command "save-off"
echo "Turned autosave off..."

# explicit save
server_command "save-all"
echo "Commanded explicit save..."
sleep 3 # wait a bit

# flush disk buffers with sync
/bin/sync
echo "Flushing disk buffers..."
sleep 1

# make snapshot
/sbin/btrfs subvolume snapshot /opt/minecraft/instances/${INSTANCE}/ /opt/minecraft/instances/${INSTANCE}.snapshot

# autosave on + message
server_command "save-on"
#server_announce "§7Snapshot completed, going read-write again and backing up the snapshot..."
echo "Turned autosave on again and notified players..."

# incremental rsync
source_dir=/opt/minecraft/instances/${INSTANCE}.snapshot/
target_dir=/opt/backup/minecraft/instances/${INSTANCE}/`date +%Y-%m-%d`/`date +%H.%M`/

# rsync -a --delete --link-dest=../backup.1 source_directory/  backup.0/
mkdir -p ${target_dir}
# rsync --verbose -a --delete ${source_dir} ${target_dir} # for initial backup
ionice -c3 rsync -a --delete --link-dest=/opt/backup/minecraft/instances/${INSTANCE}/latest_backup ${source_dir} ${target_dir} # for incremental backups

unlink /opt/backup/minecraft/instances/${INSTANCE}/latest_backup
ln -s ${target_dir} /opt/backup/minecraft/instances/${INSTANCE}/latest_backup

# remove snapshot
/sbin/btrfs subvolume delete /opt/minecraft/instances/${INSTANCE}.snapshot
#server_announce "§7All done turning the snapshot into an incremental backup, have a nice day! :)"
server_announce "§7(backup partition is `df -h /opt/backup/ | grep backup | awk '{print $5}'` full)"

echo "===== Backup finished at `date +%H:%M:%S` ====="

# optional thinning
# message status