minecraft

#!/bin/bash
# /etc/init.d/minecraft
# version 2014-08-16 (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 CraftBukkit Minecraft server
### END INIT INFO

# minecraft-init-script - An initscript to start Minecraft or CraftBukkit
# Copyright (C) 2011-2014 Super Jamie <jamie@superjamie.net>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

# Source the function library
## CentOS/Fedora
if [ -f /etc/rc.d/init.d/functions ]
 then
 . /etc/rc.d/init.d/functions
fi
## Ubuntu
if [ -f /lib/lsb/init-functions ]
 then
 . /lib/lsb/init-functions
fi

<<COMMENT
## ---------------------------------------------------------
## copy between these lines and place them at /etc/default/minecraft
## do not include the <<COMMENT and COMMENT words

## Settings for minecraft-init-script

# Nice looking name of service for script to report back to users
SERVERNAME="CraftBukkit"

# Filename of server binary
SERVICE="craftbukkit.jar"

# URL of server executable for update checking - http://cbukk.it/craftbukkit.jar is the recommended latest Craftbukkit URL
SERVER_URL="http://cbukk.it/craftbukkit.jar"

# Username of non-root user who will run the server
USERNAME="bukkit"

# Path of server binary and world
MCPATH="/home/bukkit/craftbukkit"

# Number of CPU cores to thread across if using multithreaded garbage collection
CPU_COUNT="2"

# Where backups go
BACKUPPATH="/home/bukkit/backups"

# How many days worth of backups to keep (default 7)
BACKUPS_TO_KEEP="7"

# Name of Screen session
SCRNAME="minecraft"

## The Java command to run the server, uncomment one INVOCATION line only!

# Nothing special, just start the server with 1Gb RAM
# INVOCATION="java -Xms1024M -Xmx1024M -Djava.net.preferIPv4Stack=true -jar $SERVICE nogui"

# This is what I run my server with, tune your RAM usage accordingly
# Tested fastest GC - Default parallel new gen collector, plus parallel old gen collector
INVOCATION="java -Xms1024M -Xmx1024M -Djava.net.preferIPv4Stack=true -XX:MaxPermSize=128M -XX:UseSSE=3 -XX:-DisableExplicitGC -XX:+UseParallelOldGC -XX:ParallelGCThreads=$CPU_COUNT -XX:+AggressiveOpts -XX:+UseCompressedStrings -jar $SERVICE nogui"

# I removed these "performance" commands as I don't see any difference with them
# -XX:+UseFastAccessorMethods -XX:+UseAdaptiveGCBoundary

# I've had a suggestion from a Java tuning engineer to use these
# -XX:+AggressiveOpts -XX:+UseCompressedStrings

# Add HugePage support if you have it configured on the OS
# You should be using HugePages if you give more than 4Gb on the Java invocation line
# -XX:+UseLargePages

SETTINGS_FILE_WORKING="1"
## End of settings file
## ---------------------------------------------------------
COMMENT

### ### ### ### ### ### ### ### ### ### ### ### ### ###
### You shouldn't need to edit anything below here! ###
### ### ### ### ### ### ### ### ### ### ### ### ### ###

## Apply the settings file

# define the location of the settings file from the name of this script
SETTINGSFILE="/etc/default/$(basename $0)"

# check the file exists, and fail if not
if [ ! -f "$SETTINGSFILE" ]
 then
 echo " * [ERROR] Settings file $SETTINGSFILE does not exist. Can't run!"
 exit 1;
fi

# if exists so source it
. "$SETTINGSFILE"

# if the settings are not applying for some reason, then fail
if [ ! "$SETTINGS_FILE_WORKING" == "1" ]
 then
 echo " * [ERROR] Settings file $SETTINGSFILE is not applying. Can't run!"
 echo " Check your options are uncommented and you haven't copied the <<COMMENT block."
 exit 1;
fi

## Get some more info from the settings file

# Find the world name from the existing server file
WORLDNAME="$(grep -E 'level-name' $MCPATH/server.properties | sed -e s/.*level-name=//)"

# Find the port number from the existing server file
SERVERPORT="$(grep -E 'server-port' $MCPATH/server.properties | sed -e s/.*server-port=//)"

## Runs all commands as the non-root user

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

## Check if the server is running or not, and get the Java Process ID if it is

server_running() {
  # Get the PID of the running Screen session:
  # ps, remove grep, look for screen, look for the screen session $SCRNAME to differentiate between multiple servers, awk out everything but the pid
  SCREENPID=""
  SCREENPID="$(ps -ef | grep -v grep | grep -i screen | grep $SCRNAME | awk '{print $2}')"
  # if the screen session with $SCRNAME is not running, then the server is not running, so we return 1 and exit the function
  if [ -z "$SCREENPID" ]
  then
   return 1
  fi
  # PID="$(ps -ef | grep -v grep | grep -i screen | grep $SCRNAME | awk '{print $2}' | xargs ps -f --ppid | grep $SERVICE | awk '{print $2}')"
  # use the screen session pid to get the parent pid, which is the actual pid of the java process, check that process is actually $SERVICE
  JAVAPID="$(ps -f --ppid $SCREENPID | grep $SERVICE | awk '{print $2}')"
  # if the java process is not running, then the server is not running, so we return 1 to exit the function
  if [ -z "$JAVAPID" ]
  then
    return 1
  fi
  # if we haven't failed those two tests, we have a running server, so we return success
  return 0
}

## Start the server executable as a service

mc_start() {
  if server_running
  then
    echo " * [ERROR] $SERVERNAME was already running (pid $JAVAPID). Not starting!"
    exit 1
  else
    echo " * $SERVERNAME was not already running. Starting..."
    echo " * Using map named \"$WORLDNAME\"..."
    as_user "cd \"$MCPATH\" && screen -c /dev/null -dmS $SCRNAME $INVOCATION"
    echo " * Checking $SERVERNAME is running..."

    # start a counter and check for 15 seconds if the server is running or not
    COUNT=0
    while [ $COUNT -lt 15 ]; do
      if server_running
      then
        echo " * [OK] $SERVERNAME is now running (pid $JAVAPID)."
	exit 0
      else
        let COUNT=COUNT+1
        sleep 1
      fi
    done
    # if we've reached here, the server hasn't started in 15 seconds
    echo " * [ERROR] Could not start $SERVERNAME."
    exit 1
  fi
}

## Stop the executable

mc_stop() {
  if server_running
  then
    echo " * $SERVERNAME is running (pid $JAVAPID). Commencing shutdown..."
    echo " * Notifying users of shutdown..."
    as_user "screen -p 0 -S $SCRNAME -X eval 'stuff \"say SERVER SHUTTING DOWN IN 10 SECONDS. Saving map...\"\015'"
    echo -n " * Saving map named \"$WORLDNAME\" to disk"
    as_user "screen -p 0 -S $SCRNAME -X eval 'stuff \"save-all\"\015'"

    # start a counter and check for 20 seconds for when the world has saved
    COUNT=0
    while [ $COUNT -lt 10 ]; do
      echo -n "."
      sleep 2
      if [ -f "$MCPATH/logs/latest.log" ]
      then
        if [[ "$(tail -n 20 $MCPATH/logs/latest.log | grep -E 'Save complete|Saved the world' | wc -l)" -gt 0 ]]; then
          COUNT=99
        fi
      fi
      let COUNT=COUNT+1
    done
    echo ""

    echo -n " * Stopping $SERVERNAME"
    as_user "screen -p 0 -S $SCRNAME -X eval 'stuff \"stop\"\015'"

    # start a counter and check for 15 seconds if the server is running or not
    COUNT=0
    while [ $COUNT -lt 15 ]; do
      if server_running
      then
        echo -n "."
        let COUNT=COUNT+1
        sleep 1
      else
        echo ""
        echo " * [OK] $SERVERNAME is shut down."
        exit 0
      fi
    done
    echo ""
    # if we've reached here, the server hasn't stopped in 15 seconds
    echo " * [ERROR] $SERVERNAME is still running (pid $JAVAPID). Could not be shutdown!"
    exit 1
  else
    echo " * [OK] $SERVERNAME is shut down."
  fi
}

## Set the server read-only, save the map, and have Linux sync filesystem buffers to disk

mc_saveoff() {
  if server_running
  then
    echo " * $SERVERNAME is running. Commencing save..."
    echo " * Notifying users of save..."
    as_user "screen -p 0 -S $SCRNAME  -X eval 'stuff \"say SERVER BACKUP STARTING. Server going read-only...\"\015'"
    echo " * Setting server read-only..."
    as_user "screen -p 0 -S $SCRNAME -X eval 'stuff \"save-off\"\015'"
    echo " * Saving map named \"$WORLDNAME\" to disk..."
    as_user "screen -p 0 -S $SCRNAME -X eval 'stuff \"save-all\"\015'"
    sync
    sleep 10
    echo " * [OK] Map saved."
  else
    echo " * [INFO] $SERVERNAME was not running. Not suspending saves."
  fi
}

## Set the server read-write

mc_saveon() {
  if server_running
  then
    echo " * $SERVERNAME is running. Re-enabling saves..."
    as_user "screen -p 0 -S $SCRNAME -X eval 'stuff \"say SERVER BACKUP ENDED. Server going read-write...\"\015'"
    as_user "screen -p 0 -S $SCRNAME -X eval 'stuff \"save-on\"\015'"
  else
    echo " * [INFO] $SERVERNAME was not running. Not resuming saves."
  fi
}

## Checks for update, exits if update not required, updates if the server is not running

mc_updatecheck() {
  echo " * Downloading latest $SERVERNAME executable..."
  as_user "cd \"$MCPATH\" && curl -# -L -o \"$MCPATH/$SERVICE.update\" \"$SERVER_URL\""

  if [ -f "$MCPATH/$SERVICE.update" ]
  then
    echo " * Checking downloaded update against existing server..."

    if $(diff "$MCPATH/$SERVICE" "$MCPATH/$SERVICE.update" >/dev/null)
    then
      echo " * You are already running the latest version of $SERVERNAME!"
      exit 0; # keep this exit in as we don't need to do anything
    fi

  else
    echo " * [ERROR] $SERVERNAME update could not be downloaded."
    exit 1
  fi

  if server_running
  then
    echo " * $SERVERNAME is running (pid $JAVAPID). Shutting down for update..."
  else
    as_user "/bin/cp \"$MCPATH/$SERVICE.update\" \"$MCPATH/$SERVICE\""
    echo " * [OK] $SERVERNAME successfully updated."
  fi
}

## Actually do the executable update

mc_updatedo() {
  if server_running
  then
    echo " * [ERROR] $SERVICE is still running (pid $JAVAPID). Cannot update!"
    exit 1
  else
    as_user "/bin/cp \"$MCPATH/$SERVICE.update\" \"$MCPATH/$SERVICE\""
    echo " * [OK] $SERVERNAME successfully updated."
  fi
}

## Check and see if a worldname was given to the backup command. Use the default world, or check the optional world exists and exit if it doesn't.

mc_checkbackup() {
  if [ -n "$1" ]
    then
    WORLDNAME="$1"
      if [ -d "$MCPATH/$WORLDNAME" ]
        then
        echo " * Found world named \"$MCPATH/$WORLDNAME\""
      else
        echo " * Could not find world named \"$MCPATH/$WORLDNAME\""
        exit 1
      fi
  fi
}

## Backs up map by rsyncing current world to backup location, creates tar.gz with datestamp

mc_backupmap() {
  echo " * Backing up $SERVERNAME map named \"$WORLDNAME\"..."
  echo " * Syncing \"$MCPATH/$WORLDNAME\" to \"$BACKUPPATH/$WORLDNAME\""
  as_user "rsync --checksum --group --human-readable --copy-links --owner --perms --recursive --times --update --delete \"$MCPATH/$WORLDNAME\" \"$BACKUPPATH\""
  # if the nether exists, back it up
  WORLDNETHER="$WORLDNAME""_nether"
  if [ -d "$MCPATH/$WORLDNETHER" ]
    then
    echo " * Syncing \"$MCPATH/$WORLDNETHER\" to \"$BACKUPPATH/$WORLDNETHER\""
  as_user "rsync --checksum --group --human-readable --copy-links --owner --perms --recursive --times --update --delete \"$MCPATH/$WORLDNETHER\" \"$BACKUPPATH\""
  else
    echo " * \"$MCPATH/$WORLDNETHER\" doesn't exist, skipping."
  fi
  # if the end exists, back it up
  WORLDTHEEND="$WORLDNAME""_the_end"
  if [ -d "$MCPATH/$WORLDTHEEND" ]
    then
    echo " * Syncing \"$MCPATH/$WORLDTHEEND\" to \"$BACKUPPATH/$WORLDTHEEND\""
    as_user "rsync --checksum --group --human-readable --copy-links --owner --perms --recursive --times --update --delete \"$MCPATH/$WORLDTHEEND\" \"$BACKUPPATH\""
  else
    echo " * \"$MCPATH/$WORLDTHEEND\" doesn't exist, skipping."
  fi
  sleep 10
  echo " * Creating compressed backup..."
  NOW="$(date +%Y-%m-%d.%H-%M-%S)"
  # Create a compressed backup file and background it so we can get back to restarting the server
  # You can tell when the compression is done as it makes an md5sum file of the backup
  as_user "cd "$BACKUPPATH" && tar cfz \""$WORLDNAME"_backup_"$NOW".tar.gz\" \"$WORLDNAME\" && md5sum \""$WORLDNAME"_backup_"$NOW".tar.gz\" > \""$WORLDNAME"_backup_"$NOW".tar.gz.md5\" &"
  echo " * [OK] Backed up map \"$WORLDNAME\"."
  # if we backed up the nether, create a backup of that too
  if [ -d "$BACKUPPATH/$WORLDNETHER" ]
    then
    as_user "cd "$BACKUPPATH" && tar cfz \""$WORLDNETHER"_backup_"$NOW".tar.gz\" \"$WORLDNETHER\" && md5sum \""$WORLDNETHER"_backup_"$NOW".tar.gz\" > \""$WORLDNETHER"_backup_"$NOW".tar.gz.md5\" &"
    echo " * [OK] Backed up map \"$WORLDNETHER\"."
  fi
  # if we backed up the end, create a backup of that too
  if [ -d "$BACKUPPATH/$WORLDTHEEND" ]
    then
    as_user "cd "$BACKUPPATH" && tar cfz \""$WORLDTHEEND"_backup_"$NOW".tar.gz\" \"$WORLDTHEEND\" && md5sum \""$WORLDTHEEND"_backup_"$NOW".tar.gz\" > \""$WORLDTHEEND"_backup_"$NOW".tar.gz.md5\" &"
    echo " * [OK] Backed up map \"$WORLDTHEEND\"."
  fi
  # we can safely background the above commands and get back to restarting the server
}

## Backs up executable by copying it to backup location

mc_backupexe() {
  echo " * Backing up the $SERVERNAME server executable..."
  NOW="$(date +%Y-%m-%d.%H-%M-%S)"
  as_user "cp \""$MCPATH"/"$SERVICE"\" \""$BACKUPPATH"/"$SERVICE"_backup_"$NOW".jar\""
  echo " * [OK] Backed up executable."
}

## Removes any backups older than $BACKUPS_TO_KEEP days, designed to be called by daily cron job

mc_removeoldbackups() {
  echo " * Removing backups older than $BACKUPS_TO_KEEP days..."
  as_user "cd \"$BACKUPPATH\" && find . -name \"*backup*\" -type f -mtime +$BACKUPS_TO_KEEP | xargs rm -fv"
  echo " * Removed old backups."
}

## Rotates logfile to server.1 through server.7, designed to be called by daily cron job

mc_logrotate() {
  # Define a function to copy the old logfile to the new
  mc_copylog() {
    as_user "/bin/cp $logfile $MCPATH/$LOGNEW"
  }

  # Server logfiles in chronological order
  LOGLIST="$(ls -r $MCPATH/server.log* | grep -v lck)"
  # How many logs to keep
  COUNT="6"
  # Look at all the logfiles
  for logfile in $LOGLIST; do
    LOGTMP="$(basename $logfile | cut -d '.' -f 3)"
    # If we're working with server.log then append .1
    if [ -z "$LOGTMP" ]
    then
      LOGNEW="server.log.1"
      mc_copylog
    # Otherwise, check if the file number is under $COUNT
    elif [ "$LOGTMP" -gt "$COUNT" ]
    then
      # If so, delete it
      as_user "rm -f $logfile"
    else
      # Otherwise, add one to the number
      LOGBASE="$(basename $logfile | cut -d '.' -f 1-2)"
      LOGNEW="$LOGBASE.$(($LOGTMP+1))"
      mc_copylog
    fi
  done
  # Blank the existing logfile to renew it
  as_user "echo -n \"\" > $MCPATH/server.log"
}

## Check if server is running and display PID

mc_status() {
  if server_running
  then
    echo " * $SERVERNAME status: Running (pid $JAVAPID)."
  else
    echo " * $SERVERNAME status: Not running."
    exit 1
  fi
}

## Display some extra environment informaton

mc_info() {
  if server_running
  then
    RSS="$(ps --pid $JAVAPID --format rss | grep -v RSS)"
    echo " - Java Path          : $(readlink -f $(which java))"
    echo " - Start Command      : $INVOCATION"
    echo " - Server Path        : $MCPATH"
    echo " - World Name         : $WORLDNAME"
    echo " - Process ID         : $JAVAPID"
    echo " - Screen Session     : $SCRNAME"
    echo " - Memory Usage       : $((RSS/1024)) Mb ($RSS kb)"
  # Check for HugePages support in kernel, display statistics if HugePages are available, otherwise skip
  if [ -n "$(grep HugePages_Total /proc/meminfo | awk '{print $2}')" -a "$(grep HugePages_Total /proc/meminfo | awk '{print $2}')" ]
  then
    HP_SIZE="$(grep Hugepagesize /proc/meminfo | awk '{print $2}')"
    HP_TOTAL="$(grep HugePages_Total /proc/meminfo | awk '{print $2}')"
    HP_FREE="$(grep HugePages_Free /proc/meminfo | awk '{print $2}')"
    HP_RSVD="$(grep HugePages_Rsvd /proc/meminfo | awk '{print $2}')"
    HP_USED="$((HP_TOTAL-HP_FREE+HP_RSVD))"
    TOTALMEM="$((RSS+(HP_USED*HP_SIZE)))"
    echo " - HugePage Usage     : $((HP_USED*(HP_SIZE/1024))) Mb ($HP_USED HugePages)"
    echo " - Total Memory Usage : $((TOTALMEM/1024)) Mb ($TOTALMEM kb)"
  fi
    echo " - Active Connections : "
    netstat --inet -tna | grep -E "Proto|$SERVERPORT"
  else
    echo " * $SERVERNAME is not running. Unable to give info."
    exit 1
  fi
}
 
## Connect to the active Screen session, disconnect with Ctrl+a then d

mc_console() {
  if server_running
  then
    as_user "screen -S $SCRNAME -dr"
  else
    echo " * [ERROR] $SERVERNAME was not running! Unable to console."
    exit 1
  fi
}

## Broadcasts a message

mc_say() {
  say_string="${@:1}"
  if [[ -z "$say_string" ]]
  then
    echo " * You need to enter your message. Usage; \"minecraft say message\""
  elif server_running
  then
    echo " * Broadcasting \"$say_string\""
    as_user "screen -p 0 -S $SCRNAME -X eval 'stuff \"say $say_string\"\015'"
  else
    echo " * [ERROR] $SERVERNAME was not running!"
    exit 1
  fi
}

## These are the parameters passed to the script

case "$1" in
  start)
 mc_start
 ;;
  stop)
 mc_stop
 ;;
  restart)
 mc_stop
 sleep 1
 mc_start
 ;;
  update)
 mc_updatecheck
 mc_stop
 mc_backupmap
 mc_backupexe
 mc_updatedo
 mc_start
 ;;
  backup)
 mc_checkbackup "$2"
 mc_saveoff
 mc_backupmap
 mc_backupexe
 mc_saveon
 ;;
  status)
 mc_status
 ;;
  info)
 mc_info
 ;;
  console)
 mc_console
 ;;
# These are intended for cron usage, not regular users.
  removeoldbackups)
 mc_removeoldbackups
 ;;
  logrotate)
 mc_logrotate
 ;;
  save-off)
 mc_saveoff
 ;;
  save-on)
 mc_saveon
 ;;
# Debug usage only
  justbackup) # don't use this while the server is running!!!
 mc_checkbackup
 mc_backupmap
 mc_backupexe
 ;;
  say)
 mc_say "${@:2}"
 ;;
  *)
 echo " * Usage: minecraft {start|stop|restart|backup (worldname)|save-on|save-off|update|status|info|console|say}"
 exit 1
 ;;
esac

exit 0