A tmux chrootable service script for RTK.

service.sh

#!/bin/bash
# /etc/init.d/redstone
# version 0.11 2016-03-27 (YYYY-MM-DD)
#
### BEGIN INIT INFO
# Provides:   minecraft_redstone
# Required-Start: $local_fs $remote_fs screen-cleanup
# 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:    Redstone Minecraft server
# Description:    Starts the redstone.space minecraft server
### END INIT INFO

###Settings

# Normal stuffs
SERVICE='redstone'
USERNAME='redstone'
MCPATH='/home/redstone/'
JAIL_PATH="/home/jail/"
INVOCATION='./start.sh'
#PID_FILE="~/.redstone.pid"

# tmux stuffs
SESSION_FILE='.tmux_session'
SESSION='redstone'
WINDOW='server'
PANE='0'
SESSION_WINDOW_PANE="$SESSION:$WINDOW.$PANE"

#################################################################################

ME=$(whoami)

if [ "$ME" = "$USERNAME" ]; then JAIL_PATH=""; fi

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

as_user "if [ ! -f '$MCPATH/$SESSION_FILE' ]; then touch '$MCPATH/$SESSION_FILE'; chmod 777 '$MCPATH/$SESSION_FILE'; fi"
SESSION_FILE=$( as_user "realpath '$MCPATH/$SESSION_FILE'" )

is_server() {
	return $( as_user "tmux -S '$SESSION_FILE' has-session -t '$SESSION_WINDOW_PANE' &> /dev/null" )
}

ssh_command() {
	ssh -i "$(realpath $1)" -t "$USERNAME@127.0.0.1" "$2" 
}

mc_start() {
	if is_server; then
		echo "$SERVICE is already running!"
	else
		echo "Starting $SERVICE..."
		executable_command="tmux -S '$SESSION_FILE' new-session -d -s '$SESSION' -n '$WINDOW' '$INVOCATION; tmux -S $SESSION_FILE kill-session -t $SESSION'"
		if [ "$ME" = "$ME" ]; then
			as_user "$executable_command"
		else
			if [ -f "$JAIL_PATH/$MCPATH/.ssh/private/internal_rsa" ]; then
				echo "Using SSH to start server!"
				ssh_command "$( printf '%s/%s/.ssh/private/internal_rsa' \"$JAIL_PATH\" \"$MCPATH\" )" "$executable_command" 
			else
				as_user "$executable_command"
			fi
		fi
		sleep 2
		if is_server; then
			echo "$SERVICE is now running."
		else
			echo "Error! Could not start $SERVICE!"
		fi
	fi
}

mc_stop() {
	if is_server; then
		echo "Stopping $SERVICE"
		as_user "tmux -S '$SESSION_FILE' send-keys -t \"$SESSION_WINDOW_PANE\" C-z '.stopwrapper' Enter"
		sleep 15
	else
		echo "$SERVICE was not running."
	fi
	if is_server; then
		echo "Error! $SERVICE could not be stopped."
		echo "  Man, try force-stop instead?"
	else
		echo "$SERVICE is stopped."
	fi
}

mc_force_stop() {
	if is_server; then
		echo "Stopping $SERVICE"
		as_user "tmux -S '$SESSION_FILE' send-keys -t \"$SESSION_WINDOW_PANE\" C-z '.forcestopwrapper' Enter"
		sleep 7
	else
		echo "$SERVICE was not running."
	fi
	if is_server; then
		echo "Error! $SERVICE could not be stopped."
		echo "Sorry, you're going to have to do this one alone!"
	else
		echo "$SERVICE is stopped."
	fi
}


mc_restart() {
	if is_server; then
		echo "Restarting $SERVICE"
		as_user "tmux -S '$SESSION_FILE' send-keys -t \"$SESSION_WINDOW_PANE\" C-z '.restart' Enter"
		sleep 7
		echo "$SERVICE was restarted."
	else
		echo "$SERVICE was not running... Starting!"
		mc_start
	fi
}

mc_command() {
	COMMAND="$*"
	pre_log_len=$(wc -l "$JAIL_PATH/$MCPATH/server/logs/latest.log" | awk '{print $1}')
	echo "$SERVICE is running... executing command"
	as_user "tmux -S '$SESSION_FILE' send-keys -t \"$SESSION_WINDOW_PANE\" C-z '$COMMAND' Enter"
	sleep .8 # assumes that the command will run and print to the log file in less than .8 seconds
	# print output
	tail -n "$(wc -l \"$JAIL_PATH/$MCPATH/server/logs/latest.log\" | awk '{print $1}')"-"$pre_log_len" "$JAIL_PATH/$MCPATH/server/logs/latest.log"

}

#Start-Stop here
case "$1" in
	start)
		mc_start
	;;
	stop)
		mc_stop
	;;
	force_stop)
		mc_force_stop
	;;
	restart)
		mc_restart
	;;
	status)
		if is_server; then
			echo "$SERVICE is running."
		else
			echo "$SERVICE is not running."
		fi
	;;
	att)
		tmux -S "$JAIL_PATH/$SESSION_FILE" att -t "$SESSION"
	;;
	command)
		if [ $# -gt 1 ] ; then
			shift
			if ! is_server; then
				echo "$SERVICE isn't running.."
				exit 1
			else
				mc_command "$*"
			fi
		else
			echo "Must specify server command (try 'help'?)"
		fi
	;;

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

exit 0