Tutorials/Ubuntu startup script

This is a simple startup-script for the upstart mechanism used by ubuntu-servers. It won't give you a console, which isn't considered a problem since there's an in game console anyway. It also doesn't update Minecraft.
Note: It's working fine in Ubuntu 14.
Further note: This configuration syntax is for the "upstart" process management system. Since 15.04, Ubuntu has moved to systemd, so you may need to explore other, systemd based options on newer Ubuntu installs. An example is below.
== Prerequisites ==
* Set up a user and group for minecraft so that it doesn't run as root
 
sudo adduser --system --home /srv/minecraft-server minecraft
sudo addgroup --system minecraft
sudo adduser minecraft minecraft # this adds user "minecraft" to the group "minecraft"
* Hand your server-installation over to your new user, for example, in /srv/minecraft-server
 sudo chown -R minecraft.minecraft /srv/minecraft-server
* Create and edit the start/stop script creating a new file under /etc/init/minecraft-server (NOT /etc/init.d but /etc/init (without the .d) ) make sure that you save the file as minecraft-server.conf
 sudo nano /etc/init/minecraft-server.conf
and pasting the following into it. Don't forget to change the directory after "chdir" to your installation.
# description "start and stop the minecraft-server"
start on runlevel [2345]
stop on runlevel [^2345]
console log
chdir YOUR_INSTALLATION_DIRECTORY
setuid minecraft
setgid minecraft
respawn
respawn limit 20 5
exec /usr/bin/java -Xms1536M -Xmx2048M -jar server.jar --nogui
Above Explained (Note, this script isn't usable.):
# description "start and stop the minecraft-server" <-- Adds a tip to what this script does.
start on runlevel [2345] <-- Tells Ubuntu when to start the server. Runlevels 2, 3, 4, and 5 are the "normal operation".
stop on runlevel [^2345] <-- Tells Ubuntu when to stop the server. The ^ means NOT.
console log <-- Logs the actions taken
chdir YOUR_INSTALLATION_DIRECTORY <-- Changes the active directory to the installation dir.
setuid minecraft <-- Sets the UserID to "minecraft" (acts like Minecraft user)
setgid minecraft <-- Sets the GroupID to "minecraft" (acts like Minecraft group)
respawn <-- Allows the program to "respawn" (restart) when it dies unexpectedly.
respawn limit 20 5 <-- Allows the program to "respawn" 20 times in 5 seconds.
exec /usr/bin/java -Xms1536M -Xmx2048M -jar server.jar --nogui <-- Below...
'exec' > Executes command
'/usr/bin/java' > Invokes Java.
'-Xms1536M' > Sets minimum allocated memory limit.
'-Xmx2048M' > Sets MAXIMUM allowable memory limit.
'-jar server.jar' > Tells Java to run the jarfile server.jar
'--nogui' > Tells minecraft-server.jar to run without a GUI. (Graphical screen).
* Following step does not work since depcrication of upstart in ubuntu 16+
* Now, install the start/stop to the default runlevels by running 
 sudo initctl reload-configuration
If you get an error saying the file does not exist, try moving the minecraft-server file to /etc/init.d/
Also, if after running sudo start minecraft-server says that they is no job for it, try running "sudo /etc/init.d/minecraft-server start"
== Usage ==
* To start the server
sudo start minecraft-server
* to stop the server
sudo stop minecraft-server
== Troubles? ==
You can check the server log by using:
sudo tail /var/log/upstart/minecraft-server.log
If that doesn't help, just contact me: User:Cel1ne
== With systemd ==
In this example, the player has created a user, as shown by Cel1ne. 
After : 
 sudo gedit /lib/systemd/system/minecraft-server.service
inside :
 [Unit] 
 Description=start and stop the minecraft-server 
 
 [Service]
 WorkingDirectory=/srv/minecraft-server
 User=minecraft
 Group=minecraft
 Restart=on-failure
 RestartSec=20 5
 ExecStart=/usr/bin/java -Xms1536M -Xmx1536M -jar server.jar --nogui
 
 [Install]
 WantedBy=multi-user.target
To enable the service : 
 sudo systemctl enable minecraft-server.service
To start the service:
 sudo systemctl start minecraft-server.service
View the status ("q" to go out of the view):
 systemctl status minecraft-server.service 
If you would like to interact with the server from your keyboard, you may use an alternative service configuration like this:
 [Unit] 
 Description=minecraft-server 
 
 [Service]
 WorkingDirectory=/home/minecraft/server
 User=minecraft
 Group=minecraft
 Type=forking
 ExecStart=/usr/bin/screen -dmS minecraft /usr/bin/java -Xms1536M -Xmx1536M -jar server.jar --nogui
 
 [Install]
 WantedBy=multi-user.target
If you have changed the service file, you should issue the 
 sudo systemctl daemon-reload
command to update the system.
Category:Server
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