Custom systemd Unit and Unit File

External

• https://access.redhat.com/solutions/912263

Internal

• systemd

Overview

This article describes the procedure to configure an arbitrary service myservice to be managed by systemd. It includes the creation of corresponding unit file and systemd configuration to start/stop the service automatically at boot/shutdown.

Important Note

This procedure was not tested step-by-step. When I have a concrete case that can be used for testing, revisit and update.

Create the Unit File

Create the /etc/systemd/system/myservice.service unit file. For more details on the location of the unit files, see systemd Concepts - Unit File Location.

touch /etc/systemd/system/myservice.service
chmod 644 /etc/systemd/system/myservice.service

Configure the Unit File

Process Started and Stopped by Auxiliary Scripts

[Unit]
Description=MyService
After=network.target

[Service]
Type=oneshot
ExecStart=/opt/myservice/bin/myservice start
ExecStop=/opt/myservice/bin/myservice stop
RemainAfterExit=yes

[Install]
WantedBy=multi-user.target

For more details on the content of the unit files, see systemd Concepts - Unit File Structure.

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

For more details on the content of the unit files, see systemd Concepts - Unit File Structure.

Notify systemd of the existence of the new unit file

systemctl daemon-reload

Exercise the Service

systemctl start myservice
systemctl status hello
systemctl restart hello
systemctl stop hello