Custom systemd Unit and Unit File: Difference between revisions
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=Enable at Boot= | =Enable at Boot= | ||
<syntaxhighlight lang='bash'> | |||
< | systemctl enable minecraft.service | ||
systemctl enable | </syntaxhighlight> | ||
</ | <syntaxhighlight lang='bash'> | ||
Created symlink from /etc/systemd/system/multi-user.target.wants/minecraft.service to /etc/systemd/system/minecraft.service. | |||
</syntaxhighlight> | |||
=Exercise the Service= | =Exercise the Service= | ||
< | <syntaxhighlight lang='bash'> | ||
systemctl start | systemctl start minecraft | ||
systemctl status | systemctl status minecraft | ||
systemctl restart | systemctl restart minecraft | ||
systemctl stop | systemctl stop minecraft | ||
</ | </syntaxhighlight> | ||
Revision as of 23:19, 19 August 2023
Internal
Overview
This article describes the procedure to configure an arbitrary service minecraft to be managed by systemd. It includes the creation of corresponding unit file and systemd configuration to start and stop the service automatically at boot, respectively shutdown.
Create the Unit File
Create the /etc/systemd/system/minecraft.service unit file. As root:
touch /etc/systemd/system/minecraft.service
chmod 644 /etc/systemd/system/minecraft.service
For more details on the location of the unit files, see:
Configure the Unit File
Process Started and Stopped by Auxiliary Scripts
This is common for Java programs, /home/minecraft/minecraft-server/minecraft is a wrapper script that starts the JVM and puts in background like this:
java -server -jar ... > $(dirname $0)/logs/stdout-and-sterr.log 2>&1 &
The unit file configuration is similar to:
[Unit]
Description=Minecraft service
After=network.target
[Service]
Type=oneshot
ExecStart=/home/minecraft/minecraft-server/minecraft start
ExecStop=/home/minecraft/minecraft-server/minecraft stop
RemainAfterExit=yes
[Install]
WantedBy=multi-user.target
Also see:
Daemon Process that Forks and Creates Its Own PID File
[Unit]
Description=MyService
After=network.target
[Service]
ExecStart=/opt/myservice/bin/myservice
Type=forking
PIDFile=/var/run/myservice.pid
[Install]
WantedBy=multi-user.target
Also see:
Notify systemd of the Existence of the New Unit File
systemctl daemon-reload
Is this really necessary? Why exactly? At this point the file is completely unknown to the system, it as not enabled.
For more details on daemon-reload see:
Enable at Boot
systemctl enable minecraft.service
Created symlink from /etc/systemd/system/multi-user.target.wants/minecraft.service to /etc/systemd/system/minecraft.service.
Exercise the Service
systemctl start minecraft
systemctl status minecraft
systemctl restart minecraft
systemctl stop minecraft