Minecraft server script (run minecraft server as a daemon in Arch)

Question

Hey all, I just finished editing and setting up a nice script to run a Minecraft server at boot in Arch. This is based on the original script on the minecraft wiki here. I've edited it to be suitable to place in your /etc/rc.d/ folder with the name "minecraft" (/etc/rc.d/minecraft).
This requires a user "minecraft" with the home directory /home/minecraft to work by default.
I decided I wanted to run the server entirely in RAM so I store all my files in /home/minecraft/backup while the server is offline. When it starts up it makes a tmpfs mount at /home/minecraft/minecraft and copies all the files there and runs from there. It makes an hourly backup using /etc/rc.d/backup stored in /home/minecraft/onlinebackup, first erasing the current backup and creating a new one. This is simply to save space. In the event of a crash without proper stopping of the daemon you will have a backup from your previous reboot (or restart of your minecraft server) in /home/minecraft/backup and one from within the previous hour in /home/minecraft/onlinebackup which I figure ought to be enough. You can manually backup at any time by restarting the daemon.
All paths can be altered. You can run this game under your normal user if you wish, just change the Settings section at the top of the file. RAM amounts may need to be increased for both the server and for the tmpfs, depending on how large your files are (mine are tiny and I have not heard of over 48MB for a game world, but you never know). Just check up on df -h every now and again to make sure your tmpfs has plenty of space, or just increase the allocated maximum size from the start. If you have low RAM you can always change the script to simply not use tmpfs.
If anyone wants, just ask and I can put up a version without tmpfs (should be easy enough to remove yourself but if you're not sure I'll do it for you)
All you need to start off with (if starting your server for the first time, using the scrip as is) is the user minecraft created, with the folders backup, onlinebackup and minecraft in the folder /home/minecraft, your minecraft_server.jar file in /home/minecraft/backup and your oninebackup file in /home/minecraft/backup.
NOTE: onlinebackup file runs from /home/minecraft/minecraft so that if your system crashes, the cron job to run the backups will fail because the link will point to a non-existant file until server is started again.
You can use these commands to with the server: /etc/rc.d/minecraft {start|stop|restart|update|backup}
The backup system is designed to wipe all previous sessions' backups upon starting the server, so do not set it to start the server at boot.
/etc/rc.d/minecraft
#!/bin/bash
# /etc/rc.d/minecraft
. /etc/rc.conf
. /etc/rc.d/functions
#Uncomment line below if using Sun JRE
#. /etc/profile
#Settings
SERVICE='minecraft_server.jar'
USERNAME="minecraft"
MCPATH='/home/minecraft/minecraft'
MCOFFLINEPATH='/home/minecraft/backup'
INVOCATION='java -Xmx768M -Xms768M -jar minecraft_server.jar nogui'
BACKUPPATH='/home/minecraft/onlinebackup'
ME=`whoami`
as_user() {
if [ "$ME" == "$USERNAME" ] ; then
bash -c "$1"
else
su -c - $USERNAME "$1"
fi
mc_start() {
stat_busy "Starting Minecraft Server"
if ps ax | grep -v grep | grep -v -i SCREEN | grep $SERVICE > /dev/null
then
echo "Tried to start but $SERVICE was already running!"
else
echo "$SERVICE was not running... starting."
#Move minecraft from backup folder to ram
mount -t tmpfs tmpfs -o size=50m $MCPATH
cp -a $MCOFFLINEPATH/* $MCPATH
echo "Files moved to RAM."
cd $MCPATH
as_user "cd $MCPATH && screen -dmS minecraft $INVOCATION"
sleep 7
if ps ax | grep -v grep | grep -v -i SCREEN | grep $SERVICE > /dev/null
then
echo "$SERVICE is now running."
#Create hourly backups while running
ln -s $MCPATH/onlinebackup /etc/cron.hourly/minecraftonlinebackup
echo "Hourly backups initiated."
else
echo "Could not start $SERVICE."
umount $MCPATH
fi
fi
add_daemon minecraft
stat_done
mc_saveoff() {
if ps ax | grep -v grep | grep -v -i SCREEN | grep $SERVICE > /dev/null
then
echo "$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 was not running. Not suspending saves."
fi
mc_saveon() {
if ps ax | grep -v grep | grep -v -i SCREEN | grep $SERVICE > /dev/null
then
echo "$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 was not running. Not resuming saves."
fi
mc_stop() {
stat_busy "Stopping Minecraft Server"
if ps ax | grep -v grep | grep -v -i SCREEN | grep $SERVICE > /dev/null
then
echo "$SERVICE is running... stopping."
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
if ps ax | grep -v grep | grep -v -i SCREEN | grep $SERVICE > /dev/null
then
echo "$SERVICE could not be shut down... still running."
else
echo "$SERVICE is shut down."
#Stop hourly backups
rm /etc/cron.hourly/minecraftonlinebackup
echo "Hourly backup halted."
#Unmount tmpfs
cp -a $MCPATH/* $MCOFFLINEPATH
umount $MCPATH
echo "Files copied to HDD."
fi
else
echo "$SERVICE was not running."
fi
rm_daemon minecraft
stat_done
mc_update() {
if ps ax | grep -v grep | grep -v -i SCREEN | grep $SERVICE > /dev/null
then
echo "$SERVICE is running! Will not start update."
else
MC_SERVER_URL=http://minecraft.net/`wget -q -O - http://www.minecraft.net/download.jsp | grep minecraft_server.jar\</a\> | cut -d \" -f 2`
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/minecraft_server.jar $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/minecraft_server.jar"
echo "Minecraft successfully updated."
fi
else
echo "Minecraft update could not be downloaded."
fi
fi
mc_backup() {
echo "Backing up minecraft world"
if [ -d $BACKUPPATH/world_`date "+%m.%d.%Y"` ]
then
for i in 1 2 3 4 5 6
do
if [ -d $BACKUPPATH/world_`date "+%m.%d.%Y"`-$i ]
then
continue
else
as_user "cd $MCPATH && cp -r world $BACKUPPATH/world_`date "+%m.%d.%Y"`-$i"
break
fi
done
else
as_user "cd $MCPATH && cp -r world $BACKUPPATH/world_`date "+%m.%d.%Y"`"
echo "Backed up world"
fi
echo "Backing up the minecraft server executable"
if [ -f "$BACKUPPATH/minecraft_server_`date "+%m.%d.%Y"`.jar" ]
then
for i in 1 2 3 4 5 6
do
if [ -f "$BACKUPPATH/minecraft_server_`date "+%m.%d.%Y"`-$i.jar" ]
then
continue
else
as_user "cd $MCPATH && cp minecraft_server.jar \"$BACKUPPATH/minecraft_server_`date "+%m.%d.%Y"`-$i.jar\""
break
fi
done
else
as_user "cd $MCPATH && cp minecraft_server.jar \"$BACKUPPATH/minecraft_server_`date "+%m.%d.%Y"`.jar\""
fi
echo "Backup complete"
#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_saveoff
mc_backup
mc_saveon
status)
if ps ax | grep -v grep | grep -v -i SCREEN | grep $SERVICE > /dev/null
then
echo "$SERVICE is running."
else
echo "$SERVICE is not running."
fi
echo "Usage: /etc/rc.d/minecraft {start|stop|update|backup|status|restart}"
exit 1
esac
exit 0
/home/minecraft/backup/onlinebackup
#!/bin/bash
# /home/minecraft/backup/onlinebackup
rm -rf /home/minecraft/onlinebackup/*
/etc/rc.d/minecraft backup
UPDATE:
rationalOgre has created an alternate script with a different backup system, which will keep compressed copies of your world indefinitely, along with a working update function. https://bbs.archlinux.org/viewtopic.php … 97#p944797
Last edited by PIMPinator (2011-06-08 14:00:54)

Answer 1

@PIMPinator - Weird. On mine, if I don't source /etc/profile it won't work. No clue what the difference is. I tested it after I got it up and running, removing different elements to see if one or the other was the problem. Without it all in place it just didn't work.
I made some modifications to your script today. Fixed "update" so it works properly. (You had it running mc_backup after mc_stop, which never worked on my system.) I basically reworked it so it runs the backup, then stops the server and performs the update in the ~/backup directory, then restarts the server. I also completely overhauled the "backup" system. (for this to work you have to comment out the rm -rf ~/onlinebackup/* directive in the onlinebackup script.) Now, it creates 4 rolling backups of the server, in tar.gz format. What this means is that over time, you will accumulate the last 4 backups for each day in your ~/onlinebackup folder. I thought about creating a cleanup function to cull anything over 2 days old but to be honest, even if your world was > 50MB, zipped up it's going to be about ~20mb which means you can have 50 of them and only be taking up a gig of server space. Anyway, here's the code if you are interested.
#!/bin/bash
# /etc/init.d/minecraft
. /etc/rc.conf
. /etc/rc.d/functions
#Comment out the following if using OpenJDK
. /etc/profile
#Settings
SERVICE='minecraft_server.jar'
USERNAME="minecraft"
MCPATH='/home/minecraft/minecraft'
MCOFFLINEPATH='/home/minecraft/backup'
INVOCATION='java -Xmx768M -Xms768M -jar minecraft_server.jar nogui'
BACKUPPATH='/home/minecraft/onlinebackup'
ME=`whoami`
as_user() {
if [ "$ME" == "$USERNAME" ] ; then
bash -c "$1"
else
su -c - $USERNAME "$1"
fi
mc_start() {
stat_busy "Starting Minecraft Server"
if ps ax | grep -v grep | grep -v -i SCREEN | grep $SERVICE > /dev/null
then
echo "Tried to start but $SERVICE was already running!"
else
echo "$SERVICE was not running... starting."
#Move minecraft from backup folder to ram
mount -t tmpfs tmpfs -o size=50m $MCPATH
cp -a $MCOFFLINEPATH/* $MCPATH
echo "Files moved to RAM."
cd $MCPATH
as_user "cd $MCPATH && screen -dmS minecraft $INVOCATION"
sleep 7
if ps ax | grep -v grep | grep -v -i SCREEN | grep $SERVICE > /dev/null
then
echo "$SERVICE is now running."
#Create hourly backups while running
ln -s $MCPATH/onlinebackup /etc/cron.hourly/minecraftonlinebackup
echo "Hourly backups initiated."
else
echo "Could not start $SERVICE."
umount $MCPATH
fi
fi
add_daemon minecraft
stat_done
mc_saveoff() {
if ps ax | grep -v grep | grep -v -i SCREEN | grep $SERVICE > /dev/null
then
echo "$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 was not running. Not suspending saves."
fi
mc_saveon() {
if ps ax | grep -v grep | grep -v -i SCREEN | grep $SERVICE > /dev/null
then
echo "$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 was not running. Not resuming saves."
fi
mc_stop() {
stat_busy "Stopping Minecraft Server"
if ps ax | grep -v grep | grep -v -i SCREEN | grep $SERVICE > /dev/null
then
echo "$SERVICE is running... stopping."
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
if ps ax | grep -v grep | grep -v -i SCREEN | grep $SERVICE > /dev/null
then
echo "$SERVICE could not be shut down... still running."
else
echo "$SERVICE is shut down."
#Stop hourly backups
rm /etc/cron.hourly/minecraftonlinebackup
echo "Hourly backup halted."
#Unmount tmpfs
cp -a $MCPATH/* $MCOFFLINEPATH
umount $MCPATH
echo "Files copied to HDD."
fi
else
echo "$SERVICE was not running."
fi
rm_daemon minecraft
stat_done
mc_update() {
if ps ax | grep -v grep | grep -v -i SCREEN | grep $SERVICE > /dev/null
then
echo "$SERVICE is running! Will not start update."
else
MC_SERVER_URL=http://minecraft.net/`wget -q -O - http://www.minecraft.net/download.jsp | grep minecraft_server.jar\</a\> | cut -d \" -f 2`
as_user "cd $MCOFFLINEPATH && wget -q -O $MCOFFLINEPATH/minecraft_server.jar.update $MC_SERVER_URL"
if [ -f $MCOFFLINEPATH/minecraft_server.jar.update ]
then
if `diff $MCOFFLINEPATH/minecraft_server.jar $MCOFFLINEPATH/minecraft_server.jar.update >/dev/null`
then
echo "You are already running the latest version of $SERVICE."
rm $MCOFFLINEPATH/minecraft_server.jar.update
else
as_user "mv $MCOFFLINEPATH/minecraft_server.jar.update $MCOFFLINEPATH/minecraft_server.jar"
echo "Minecraft successfully updated."
fi
else
echo "Minecraft update could not be downloaded."
fi
fi
mc_backup() {
echo "Backing up minecraft world"
local COUNTER=
if [ -f $BACKUPPATH/co ]
then
COUNTER=`cat $BACKUPPATH/co`
if [ $COUNTER -gt 4 ]
then
#Loop back to 1 if greater than the max number of desired saves (4 hardcoded)
as_user "echo 1 > $BACKUPPATH/co"
COUNTER=1
fi
else
COUNTER=1
as_user "echo 1 > $BACKUPPATH/co"
fi
if [ -f $BACKUPPATH/world_`date "+%m.%d.%Y"`-$COUNTER.tar.gz ]
then
as_user "rm $BACKUPPATH/world_`date "+%m.%d.%Y"`-$COUNTER.tar.gz"
fi
as_user "cd $MCPATH && tar -czf $BACKUPPATH/world_`date "+%m.%d.%Y"`-$COUNTER.tar.gz world"
#now to update the counter
as_user "echo $(($COUNTER + 1)) > $BACKUPPATH/co"
echo "Backup complete..."
#Start-Stop here
case "$1" in
start)
mc_start
stop)
mc_stop
restart)
mc_stop
mc_start
update)
mc_saveoff
mc_backup
mc_saveon
mc_stop
mc_update
mc_start
backup)
mc_saveoff
mc_backup
mc_saveon
status)
if ps ax | grep -v grep | grep -v -i SCREEN | grep $SERVICE > /dev/null
then
echo "$SERVICE is running."
else
echo "$SERVICE is not running."
fi
echo "Usage: /etc/rc.d/minecraft {start|stop|update|backup|status|restart}"
exit 1
esac
exit 0
I hope you don't mind.
EDIT: Made a small change later that I came back and put in. If you are currently at the latest release it removes the .update file it created.
Last edited by rationalOgre (2011-06-07 23:05:58)