Creating a systemd service + timer for daily update

[gombosg]

Thought it might be useful to share this.
This updates the hosts.deny file daily. This is safe to do if you don't use that file for any other purpose.

Creating a service

# systemctl edit --force --full hosts-deny-update.service

Add something like this (copy the ExecStart code form the relevant updater script):

[Unit]
Description=Download host.deny file
After=network.target

[Service]
Type=simple
ExecStart=wget https://hosts.ubuntu101.co.za/hosts.deny -O /etc/hosts.deny

Save and test the service:

# systemctl start hosts-deny-update.service
# systemctl status hosts-deny-update.service

Creating a timer

# systemctl edit --force --full hosts-deny-update.timer

Add this, it triggers the service automatically as long as the timer and the service have the same name.

[Unit]
Description=Update hosts deny file

[Timer]
OnCalendar=daily
Persistent=true

[Install]
WantedBy=timers.target

Then enable:

# systemctl enable --now hosts-deny-update.timer

That's it! Enjoy!

Additional Docs

• Fedora systemd docs
• Arch wiki systemd timers