Minecraft Server Control Script
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Originally posted by sandain on the Minecraft Forums on 9 Mar 2013. 
Modified extensively by WebMaka (general@actiumgaming.com), et al

Forum thread:
http://www.minecraftforum.net/topic/121830-multi-world-linux-minecraft-server-control-script/


Installing:

1. Upload this script and template.conf to a Linux server.
2. Pop open a terminal and paste/run these lines, one at a time:
     sudo cp minecraft_server /etc/init.d/minecraft_server
     sudo chmod 755 /etc/init.d/minecraft_server
     sudo update-rc.d minecraft_server defaults
     sudo adduser minecraft
   NOTE: Obviously you'll need root for this, and when doing the adduser line leave everything
   blank but the password - give the new user a properly strong password.
3. Be sure to chown the script file in /etc/init.d to the user "minecraft" (or whatever you
   change the user to) so that it can be invoked properly.
4. Edit worlds.conf to add world names (essentially names for each server instance), ports, and
   optionally IP addresses, for each server instance you want to run on the machine.
5. Copy template.conf and rename a copy to <world>.conf for each world entry in worlds.conf.
6. Edit the <world>.conf files as needed. MAKE SURE YOU SAVE EVERYTHING USING UNIX NEW-LINE
   CONVENTIONS. Windows uses CRLFs but *NIX only uses linefeeds, and if you save this script
   and/or any <world>.conf file using Windows CRLFs the script WILL crash and/or not work properly.
7. Start each server with "/etc/init.d/minecraft_server watchstart <world>" and monitor to ensure
   everything works as desired. if all went well, great! if not, well, fix as required. ;-)
8. Edit the <world>.conf files again if necessary/desired to optimize Java start parameters, improve
   performance, etc.


Commands:

NOTE: When [<world>] is the parameter, the command will work on/for the server for the given <world>,
or all Configured servers if no world is specified. Nevertheless, a few commands are world-specific.

> start [<world>]: Start the server for instance <world>, or start all server instances.
> watchstart <world>: Start the server, and switch to its screen to see the startup process in real time.
> stop [<world>]: Stop the server.
> force-stop [<world>]: Kill the server's running process.
> restart [<world>]: Stop and restart the server.
> force-restart [<world>]: Kill the server's running process and restart the server.
> scheduled-restart <world>: Stop and restart the server, giving warnings as far as 10 minutes in 
   advance. (Intended to be cronned.)
> powercycle [<world>]: Stop, back up, and restart the server. (NOTE: Backs up only the world files - 
   essentially this combines "restart" and "backup".
> status [<world>]: View the server's current status (running or not), and player count if applciable.
> sync [<world>]: Sync the server's world files to the . files on disk if mirroring is enabled.
> send <world> <command>: Send a single <command> to the server. Anything sent as <command> is 
   essentially run as a console command, so use with caution.
> screen <world>: Switch to the server's screen.
> watch <world>: Monitor the server by watching for server log changes. This basically only displays 
   major events - use "screen" to watch minor events, mod messages, and debugging information.
> logrotate [<world>]: Rotate the server's log files.
> savetodisk [<world>]: Flush all pending world updates to disk - includes "sync" functionality if
   mirroring is enabled.
> backup [<world>]: Back up the server's world files. NOTE: This can take several minutes and can slowly 
   consume a lot of disk space over time.
> fullbackup [<world>]: Back up the entire server. NOTE: This can take half an hour or more and will eat
   a lot of disk space.
> map [<world>]: Redo the Overviewer map for the server, if Overviewer is installed.


Suggestions:

- Once you're sure a newly added server is working properly, use the "fullbackup" command with
  tarball creation enabled to create an easy-to-reinstall copy in case something blows up.
- Add a cron task to run the "savetodisk" command on regular intervals. 15-30 minutes is good for
  non-mirrored servers, but go with 5-10 minute intervals for mirrored so data loss risks are
  reduced.
- Add a cron task to run the "backup" command on regular intervals to archive each server's world
  files. 6-24 hours is about right, but beware of disk space usage if you enable tarball creation
  and have a short interval; 6-hour backup intervals can make a terabyte of space vanish in a
  month unless you change the BACKUP_DURATION value to something reasonable!
- For really mod-heavy servers (e.g., Tekkit, Feed the Beast) it might not be a bad idea to add a
  cron task to run the "scheduled-restart" command to stop and restart the server. This is a good
  idea because large amounts of mods can make Java leak so much memory it becomes slow and unstable
  after a couple days. Usually, restarting such servers once a day during the lowest-traffic part
  of the day is fine.


Change Log:

- fix the detection of required programs.  Error messages should now display correctly 
  if a program is found to be missing.
- fix the permissions for the screen tty using Montoya's patch.
- Add the logrotate command to the script for rotating the log file using a modified version 
  of Zanix's patch.
- Search the world folder for an overviewer-settings.py file for custom mapping settings for 
  the world using Zanix's patch.
- Use the update infrastructure to manage the Minecraft client download using Zanix's patch.
- Catch banned players logging off of the server using Zanix's patch.
- Add support for Minecraft Overviewer and drop support for c10t and Pigmap.
- Remove support for mcsuperserver.py, it is buggy and does not have an update for Minecraft 1.4.
- Remove support for user and admin commands.  They no longer work with Minecraft 1.4.
- Use Paul Andreassen's mcsuperserver.py to launch servers on demand as recommend by Culfri.
- Add support for the Pigmap mapping software.
- Added Zanix's backup patch.
- Add a more descriptive error for when the server fails to start.
- fix an issue with wget not being able to download CraftBukkit at its current address (was 
  breaking on the &).
- Once again update the CraftBukkit download location to point to their latest release.
- Add a separate variable for admin level user commands, but just give them access to the motd for now.
- Recognise admins attempting to run a command.
- Update the CraftBukkit download location to point to their latest stable build (fixes 1.0).
- Add an IP address field to the worlds.conf file, blank by default.
- Add the option to utilize a mirror image of a world for use in ramdisk CONFIGurations.
- Modify init info to include support for chkCONFIG.
- Add a lock file when running under RedHat/CentOS to fix shutdown issues (found by swallowtail23).
- Display a message prior to displaying a world's screen about how to exit that screen.
- fix a bug in detecting the process ID of Screen when there are very similar world names (found by 
  Tachdelan).
- fix mapping of the Nether when using CraftBukkit.
- Update the CraftBukkit download location to point to their latest stable build (fixes beta 1.8).
- Simplify the server type selection code as suggest by hexparrot.
- Verify the download of c10t.
- Add /help and /motd user commands.
- Follow symbolic links when creating tar archives during a full backup.
- Make the auto restart on SEVERE server event optional.
- Simplify the Nether detection method, fixing the mapping of the Nether in 1.6.
- Print a message if running the script as the wrong user.
- Add current version detection for c10t download.
- fix c10t download.
- Add support for CraftBukkit.
- Add an option to connect to the Screen holding the world's console.
- Restart the server when a SEVERE server event is caught.
- fix mapping of Nether worlds with c10t.ftb_ultimate
- Allow spaces in addition to tabs in the worlds.conf file.
- Allow the script to run from a user account.
- Add the watch command line option to allow the server admin to watch the log file.
- Add options to route lib-notify output to the correct user and display.
- Make sure the server.log file exists prior to starting the log processor.
- Allow comments in the worlds.conf file.
- Be more verbose when doing updates to the server software.
- Add a Message of the Day (MOTD) that is whispered to users when they log on.
- fix lib-notify output.
- Remove the time from backup files, instead use a counter for multiple backups in the same day.  This 
  should fix issues with file systems that don't like using a colon in the filename.
- Output the number of online users when the scripts status command is given.
- fix 32/64 bit detection (used for updating c10t).
- Add initial log processing.  Keep track of users logging in and out.
- Make the script use the same world names as Minecraft.
- Add error checking to calls to wget and screen.
- Add backup duration variable and logic.  Backups older than X days are now removed when new 
  backups are created.
- Directories are now created properly when maps are first created with c10t.
- Add send option, to send a command to the world server.
- Add an infrastructure for updating addons, and add c10t to the update routine.
- Add force-stop and force-restart options to kill a world server process after attempting a clean
  shutdown.  This will allow admins to stop locked servers more easily.

Changes made by WebMaka during May-June 2013:
- Changed the launch code to place server-centric CONFIGurations in separate files for each 
  instance. This permits the script to manage multiple servers with different jar files and
  their own special sets of Java startup parameters.
- Added sanity checking and autocreate-if-missing for world CONFIGuration files.
- Modified the mirroring code to mirror world files only, auto-creating and removing symlinks
  and remaning the original world file directory as needed.
- Re-added tarball creation to the script's backup options. When enabled, the script can back 
  up the world files or whole server instance to a .tar.gz archive file. This can be used in 
  conjunction with rdiff-backup to provide both incremental mirrored backups AND downloadable,
  offsite-storable archives.
- Made script responses more verbose/useful, and added some basic formatting to them. Piping
  script execution results to text files for later examination can actually be useful now.
- Added "powercycle" command, which combines "restart" and "backup" to stop the server, back up its
  world files, and then restart the server.
- Added "scheduled-restart" command, which is basically "restart" with warnings at 10 and 5 minutes
  before shutdown as well as 60, 30, 15, 10, and 5 seconds before. This command is intended to be 
  "cronned" to auto-restart servers on a regular basis when they require it in order to maintain
  stability.
- Added "watchstart" command, which combines "start" with "screen" to start the server and jump right
  into its startup process. Wonderful for seeing what's doing what during startup.
- Added "savetodisk" command, which expands on the "sync" command to save pending world file updates
  to disk, including mirrored world files which are then copied to disk.
- Edited all server stop/restart commands to give warnings at 60, 30, 15, 10, and 5 seconds before 
  dropping the server. Gives more time for players to panic and complain before the server stops. ;-)
- Cleaned up a lot of the comment text, revamped descriptions, etc. to make things a bit clearer.