Tutorials/Server startup script

This is an example of possible Minecraft server startup and maintenance script for GNU/Linux distros.

[edit] Pre-Requisites

Screen package must be installed.
On Red Hat-based distributions:

yum install screen

On Debian based systems such as Ubuntu:

apt-get install screen

[edit] Download

To download the script with wget, run the following (WATCH OUT SCRIPT NEEDS WORK):

wget -O minecraft "http://www.minecraftwiki.net/wiki/Tutorials/Server_startup_script/Script?action=raw"

[edit] Script

#!/bin/bash
# /etc/init.d/minecraft
# version 0.3.9 2012-08-13 (YYYY-MM-DD)

### BEGIN INIT INFO
# Provides:   minecraft
# Required-Start: $local_fs $remote_fs
# Required-Stop:  $local_fs $remote_fs
# Should-Start:   $network
# Should-Stop:    $network
# Default-Start:  2 3 4 5
# Default-Stop:   0 1 6
# Short-Description:    Minecraft server
# Description:    Starts the minecraft server
### END INIT INFO

#Settings
SERVICE='minecraft_server.jar'
OPTIONS='nogui'
USERNAME='minecraft'
WORLD='world'
MCPATH='/home/minecraft/minecraft'
BACKUPPATH='/media/remote.share/minecraft.backup'
MAXHEAP=2048
MINHEAP=1024
HISTORY=1024
CPU_COUNT=1
INVOCATION="java -Xmx${MAXHEAP}M -Xms${MINHEAP}M -XX:+UseConcMarkSweepGC \
-XX:+CMSIncrementalPacing -XX:ParallelGCThreads=$CPU_COUNT -XX:+AggressiveOpts \
-jar $SERVICE $OPTIONS"

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

mc_start() {
  if  pgrep -u $USERNAME -f $SERVICE > /dev/null
  then
    echo "$SERVICE is already running!"
  else
    echo "Starting $SERVICE..."
    cd $MCPATH
    as_user "cd $MCPATH && screen -h $HISTORY -dmS minecraft $INVOCATION"
    sleep 7
    if pgrep -u $USERNAME -f $SERVICE > /dev/null
    then
      echo "$SERVICE is now running."
    else
      echo "Error! Could not start $SERVICE!"
    fi
  fi
}

mc_saveoff() {
  if pgrep -u $USERNAME -f $SERVICE > /dev/null
  then
    echo "$SERVICE is running... suspending saves"
    as_user "screen -p 0 -S minecraft -X eval 'stuff \"say SERVER BACKUP STARTING. Server going readonly...\"\015'"
    as_user "screen -p 0 -S minecraft -X eval 'stuff \"save-off\"\015'"
    as_user "screen -p 0 -S minecraft -X eval 'stuff \"save-all\"\015'"
    sync
    sleep 10
  else
    echo "$SERVICE is not running. Not suspending saves."
  fi
}

mc_saveon() {
  if pgrep -u $USERNAME -f $SERVICE > /dev/null
  then
    echo "$SERVICE is running... re-enabling saves"
    as_user "screen -p 0 -S minecraft -X eval 'stuff \"save-on\"\015'"
    as_user "screen -p 0 -S minecraft -X eval 'stuff \"say SERVER BACKUP ENDED. Server going read-write...\"\015'"
  else
    echo "$SERVICE is not running. Not resuming saves."
  fi
}

mc_stop() {
  if pgrep -u $USERNAME -f $SERVICE > /dev/null
  then
    echo "Stopping $SERVICE"
    as_user "screen -p 0 -S minecraft -X eval 'stuff \"say SERVER SHUTTING DOWN IN 10 SECONDS. Saving map...\"\015'"
    as_user "screen -p 0 -S minecraft -X eval 'stuff \"save-all\"\015'"
    sleep 10
    as_user "screen -p 0 -S minecraft -X eval 'stuff \"stop\"\015'"
    sleep 7
  else
    echo "$SERVICE was not running."
  fi
  if pgrep -u $USERNAME -f $SERVICE > /dev/null
  then
    echo "Error! $SERVICE could not be stopped."
  else
    echo "$SERVICE is stopped."
  fi
}

mc_update() {
  if pgrep -u $USERNAME -f $SERVICE > /dev/null
  then
    echo "$SERVICE is running! Will not start update."
  else
    MC_SERVER_URL=http://s3.amazonaws.com/MinecraftDownload/launcher/minecraft_server.jar?v=`date | sed "s/[^a-zA-Z0-9]/_/g"`
    as_user "cd $MCPATH && wget -q -O $MCPATH/minecraft_server.jar.update $MC_SERVER_URL"
    if [ -f $MCPATH/minecraft_server.jar.update ]
    then
      if `diff $MCPATH/$SERVICE $MCPATH/minecraft_server.jar.update >/dev/null`
      then 
        echo "You are already running the latest version of $SERVICE."
      else
        as_user "mv $MCPATH/minecraft_server.jar.update $MCPATH/$SERVICE"
        echo "Minecraft successfully updated."
      fi
    else
      echo "Minecraft update could not be downloaded."
    fi
  fi
}

mc_backup() {
   mc_saveoff
   
   NOW=`date "+%Y-%m-%d_%Hh%M"`
   BACKUP_FILE="$BACKUPPATH/${WORLD}_${NOW}.tar"
   echo "Backing up minecraft world..."
   #as_user "cd $MCPATH && cp -r $WORLD $BACKUPPATH/${WORLD}_`date "+%Y.%m.%d_%H.%M"`"
   as_user "tar -C \"$MCPATH\" -cf \"$BACKUP_FILE\" $WORLD"

   echo "Backing up $SERVICE"
   as_user "tar -C \"$MCPATH\" -rf \"$BACKUP_FILE\" $SERVICE"
   #as_user "cp \"$MCPATH/$SERVICE\" \"$BACKUPPATH/minecraft_server_${NOW}.jar\""

   mc_saveon

   echo "Compressing backup..."
   as_user "gzip -f \"$BACKUP_FILE\""
   echo "Done."
}

mc_command() {
  command="$1";
  if pgrep -u $USERNAME -f $SERVICE > /dev/null
  then
    pre_log_len=`wc -l "$MCPATH/server.log" | awk '{print $1}'`
    echo "$SERVICE is running... executing command"
    as_user "screen -p 0 -S minecraft -X eval 'stuff \"$command\"\015'"
    sleep .1 # assumes that the command will run and print to the log file in less than .1 seconds
    # print output
    tail -n $[`wc -l "$MCPATH/server.log" | awk '{print $1}'`-$pre_log_len] "$MCPATH/server.log"
  fi
}

#Start-Stop here
case "$1" in
  start)
    mc_start
    ;;
  stop)
    mc_stop
    ;;
  restart)
    mc_stop
    mc_start
    ;;
  update)
    mc_stop
    mc_backup
    mc_update
    mc_start
    ;;
  backup)
    mc_backup
    ;;
  status)
    if pgrep -u $USERNAME -f $SERVICE > /dev/null
    then
      echo "$SERVICE is running."
    else
      echo "$SERVICE is not running."
    fi
    ;;
  command)
    if [ $# -gt 1 ]; then
      shift
      mc_command "$*"
    else
      echo "Must specify server command (try 'help'?)"
    fi
    ;;

  *)
  echo "Usage: $0 {start|stop|update|backup|status|restart|command \"server command\"}"
  exit 1
  ;;
esac

exit 0

[edit] Requirements

• screen

[edit] Installation

Use your favorite editor to create file called minecraft in /etc/init.d/ and paste the script above in that file.

Edit the USERNAME and MCPATH -variables according to your setup. If you use a wrapper script, change INVOCATION to start it instead of starting the server directly.

Make sure the newly created file has required permissions You can set the permissions by running:

chmod a+x /etc/init.d/minecraft

Then run (on Debian-based distributions)

update-rc.d minecraft defaults

to add required symbolic links. Note: your system will most likely warn you that the script does not meet all requirements. The script will however work.

You can also setup an entry in your crontab to backup the server. A sample crontab to backup every half hour on the hour, and 30 minutes into the hour:

• Using the user account you want the work done under, run:

crontab -e

and add this

0,30 * * * * /etc/init.d/minecraft backup

If the above attempt went poorly because you do not know how to use vi, try:

VISUAL=/usr/bin/nano crontab -e

[edit] Uninstall

(In debian based GNU/Linux distribution)

update-rc.d -f  minecraft remove

[edit] Usage

The script may be invoked via the following command on most systems, where "(command)" will be "stop", "start", "restart", or any of the other options it supports.

/etc/init.d/minecraft (command)

On most RedHat- or Debian-based distribution where the `service` command is available, it should be invoked as:

service minecraft (command)

To view the screen, use:

screen -r

To exit the screen, use:

CTRL+a+d

[edit] References

http://www.debian-administration.org/articles/28

[edit] Extra information

If you still want to view the live log file, use this command in the server directory.

tail -f server.log

[edit] Alternative Startup Scripts

The following scripts offer the same functions as the above script but contain more useful features:

• Minecraft Server Manager An improvement of this script with comprehensive features and multi-server support.
  • Features include "super responsive" commands return as soon as possible, minimising player down time.
  • Keeps players informed with configurable in-game messages, such as "Shutting down in 10 seconds!"
  • Periodical WorldEdit compatible world backups.
  • Load worlds into RAM for fast access reducing lag.
  • Tab completion on all commands makes learning easy.
  • Visit Minecraft Server Manager's GitHub page for the full list of features.
• mcwrapper
• [Multi World] GNU/Linux Minecraft server control script
  • Run multiple Minecraft worlds.
  • Uses Paul Andreassen's MCSuperServer to launch servers on demand, saving system resources.
  • Supports CraftBukkit in addition to the standard Mojang server distribution.
  • Users automatically notified of important server events.
  • Keep track of users logged into the world servers.
  • Start, stop, and restart single or multiple worlds.
  • LSB-compatible init script, allows for seamless integration with your server's startup and shutdown sequences.
  • Map worlds using the c10t and Pigmap mapping software.
  • Backup worlds, and remove backups older than X days.
  • Update the server software and installed addons.
  • Send commands to a world server from the command line.
• MC Sheller
• minecraft init
  • modification of this script with a lot more features like multiworld
• Dagmar d'Surreal's Sysv init script
• Setsuna-Xero's OpenRC(Gentoo) compatible init script, with conf.d defaults
• Mineserv Perl Init Script
  • A very simple automatic start/stop script with backup and cleanup functions and the ability to pass commands to the server console.