Using systemd Timer

What is systemd?

systemd is the standard service manager used by most modern Linux distributions.

A systemd timer is used to schedule tasks in a similar way to a cron job. Timers can run commands based on specific times, dates, or intervals.

Watch My Domains SED uses a timer to periodically execute the cron.php script which processes the lookup queue and performs scheduled checks.

Using systemd Instead of Cron

To run the scheduled job using systemd, create two files:

• A service unit which defines the command to run
• A timer unit which defines when the command should run

Please adjust the paths in the examples below to match your installation.

Service File

Create the following file:

/etc/systemd/system/wmdsed.service

[Unit]
Description=Watch My Domains SED Cron Task

[Service]
Type=oneshot
ExecStart=php /var/www/html/wmdsed60/cron.php
WorkingDirectory=/var/www/html/wmdsed60/

Timer File

Create the following file:

/etc/systemd/system/wmdsed.timer

[Unit]
Description=Watch My Domains SED Timer

[Timer]
OnCalendar=*-*-* *:*:00
Persistent=true

[Install]
WantedBy=timers.target

Enable and Start the Timer

After creating the files, reload systemd and enable the timer.

sudo systemctl daemon-reload
sudo systemctl enable wmdsed.timer
sudo systemctl start wmdsed.timer

Verify the Timer

You can confirm that the timer is active using:

systemctl status wmdsed.timer

To list all active timers:

systemctl list-timers

The timer runs the task once every minute, which is the recommended schedule for processing the lookup queue.