<< Back to cheatsheets

systemd.unit

Reference manpage: man systemd.unit

systemd.unit - Unit configuration

Create service user and group

It is highly advised to create separate service user and limit it's access only that is necessary to operate Service accounts are unable to log in

useradd --system --shell /usr/sbin/nologin --no-create-home <username>

Creating a new systemd service

This involves defining a "unit file" with a .service extension. These files are typically placed in /etc/systemd/system/ for system-wide services, or ~/.config/systemd/user/ for user-specific services. Here's an example of a simple service definition (e.g., /etc/systemd/system/myapp.service):

[Unit]
Description=My custom service
After=network.target

[Service]
ExecStart=/opt/app/app.py --port 8080
Restart=on-failure
RestartSec=5s
WorkingDirectory=/opt/app

#Type=simple
#StandardOutput=journal
#User=user
#Group=group
#Environment="MY_ENV_VAR=production"
#LimitNOFILE=65536
#MemoryLimit=256M

[Install]
WantedBy=default.target

Enable and start service

After creating the service file, you need to tell systemd to reload its configuration and then enable/start your service

sudo systemctl daemon-reload
sudo systemctl enable myapp
sudo systemctl start myapp
sudo systemctl status myapp