debian-tmux

#!/bin/bash
# /etc/init.d/minecraft
# version 0.0.1 2014-03-18 (YYY-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

# Variables

SRV_PATH='/srv/minecraft/' ## location of minecraft service folder, LEAVE THE / ON THE END
JAR_FILE='forge.jar' ## location of minecraft jar, in relation to SRV_PATH
JAR_OPTS='nogui' ## custom operators for java
SRV_NAME='ftb' ## name for service, used for tmux session
USER='minecraft' ## user to run service as
WORLD='world/' ## world dir, in relation to SRV_PATH
FULL_BACKUP_DIR='/srv/backup/minecraft.full' ## location of backup dir, leave blank to disable, supports rsync over ssh
DIFF_BACKUP_DIR='/srv/backup/minecraft' ## location of differential backup dir
CPUS=2 ## number of cores for java to use
MAX_RAM='6192M' ## maximum memory allowed for java
RES_RAM='1024M' ## starting ram for java
JAVA_OPTS="-Xmx${MAX_RAM} -Xms${RES_RAM} -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalPacing -XX:ParallelGCThreads=${CPUS}" ##all options for java 
AS_USER="$(which sudo) -u ${USER}" ## save this for later, we're gonna be using it a lot


## Functions

check_running(){
	if $(which pgrep) -u $USER -f $JAR_FILE > /dev/null ## check if process exists for jar file
	then
		return 0 ## when process is found
	else
		return 1 ## when process is not found, ie server not running
	fi
}

send_command(){
	$AS_USER $(which tmux) send -t $SRV_NAME "$1" ENTER ## run tmux as minecraft user, and send command followed by newline
}

attach_console(){
	if check_running ## see if it's running
	then
		$AS_USER $(which tmux) attach -t $SRV_NAME ## attach to tmux session
	else
		echo "Connection failed, server is not running"
	fi
}

disable_save(){
	if check_running ## make sure the server is running
	then
		send_command "say Prepare your anuses, time for a backup!"
		send_command "save-off"  ## turn off auto saving, otherwise this is gonna break
		send_command "save-all"  ## Horse save current state
		sync ## flush fs buffer, because reasons
		sleep 2 ## wait a bit, give stuff time to catch up
	fi
}

enable_save(){
	if check_running ## make sure server is running first
	then
		send_command "save-on" ## turn auto saving back on
		send_command "say And relax, backup complete!"
	fi
}

start_server(){
	echo -n "Starting ${SRV_NAME}: " ## self explanatory
	if check_running ## is it already running?
	then
		echo "Failed, ${SRV_NAME} already running" ## it was already running.
	else
		cd $SRV_PATH ## get to where minecraft is
		echo "i'm in" $SRV_PATH 
		$AS_USER $(which tmux) new -d -s ${SRV_NAME} "$(which java) ${JAVA_OPTS} -jar ${JAR_FILE} ${JAR_OPTS}" ## apparently, this runs the jar, looks like a mess to me...
		echo "got here now"
		sleep 5 ## give the server a chance to start, might wanna up this with lots of plugins
		if check_running ## did it work?
		then
			echo "Success" ## yay, it worked!
		else
			echo "Failed, check the logs!" ## uh-oh, something went wrong, not our fault!
		fi
	fi
}

stop_server(){
	echo -n "Stopping ${SRV_NAME}: " ## do i really need to explain this?
	if check_running ## see if we can actually stop it
	then
		send_command "say Oh lordy, it's a shutdown!" ## warn everyone

		sleep 3 ## let people see the message

		send_command "stop" ## stop the server

		sleep 5 ## minecraft is slow, wait for it to shut down

		if check_running ## did we actually stop it?
		then
			echo "Failed, try killing the process yourself?" ## Well, this is bad...
		else
			echo "Success" ## Huzzah, we managed to stop it, aren't you proud?
		fi
	else
		echo "Failed, ${SRV_NAME} not running" ## how can you make a phone call, if you cannot speak?
	fi
}

backup_world(){
	echo -n "Backing up World: "
	if [ ! -z $BACKUP_DIR ] ## see if there is a backup dir set
	then
		if [ -d $BACKUP_DIR ]
		then
			disable_save ## turn of saving, otherwise chaos will ensue
			$AS_USER $(which rsync) --archive --quiet ${SRV_PATH}${WORLD} $BACKUP_DIR ## rsync, without telling the user, sneaky sneaky
			enable_save ## turn saving back on, we're done now
			echo "Success"
		else
			echo "Failed - Backup directory doesn't exist!"
		fi
	else
		echo "Failed, no backup dir set!" ## this was an option, if you remember
	fi
}

diff_backup_world(){
	echo -n "Performing differential backup: "
	if [ ! -z $DIFF_BACKUP_DIR ]
	then
		if [ -d $DIFF_BACKUP_DIR ]
		then
			disable_save
			$AS_USER $(which rdiff-backup) ${SRV_PATH}${WORLD} $DIFF_BACKUP_DIR
			enable_save
			echo "Success"
		else
			echo "Failed - Differential backup dir does not exist!"
		fi
	else
		echo "Failed, no differential backup dir set!"
	fi
}

case "$1" in
	start)
		start_server ;; ## start the server, if arg1 was start
	stop)
		stop_server ;; ## come on, this is obvious
	restart)
		stop_server
		sleep 1
		start_server ;;  ## do you really need help with this?
	backup)
		backup_world ;;
	diff_backup)
		diff_backup_world ;;
	console)
		attach_console ;;
	status)
		if check_running
		then
			echo "${SRV_NAME} is running"
		else
			echo "${SRV_NAME} is not running"
		fi ;;
	*)
	echo "Usage: /etc/init.d/minecraft {start|stop|restart|backup|diff_backup|console|status}"
	exit 1 ;;
esac

exit 0