I use healthchecks.io to monitor several cronjobs and this works great.

Recently I have been using systemd timers instead of cronjobs but wanted to continue to use healthchecks with them. I accomplished this using ExecStartPre and ExecStartPost in the service file.

To add these checks to the dnf-automatic.service,

1. Edit the service file systemctl edit dnf-automatic.service
2. Add a [Service] section
3. Add a ExecStartPre= and ExecStartPost directive calling healthchecks.io

[root@mx1 dnf]# cat /etc/systemd/system/dnf-automatic.service.d/override.conf
[Service]
ExecStartPre=/usr/bin/curl -fsS -m 10 --retry 5 -o /dev/null https://hc-ping.com/${UUID}/start
ExecStopPost=/usr/bin/curl -fsS -m 10 --retry 5 -o /dev/null https://hc-ping.com/${UUID}

By adding /start to the curl command, you can log the run time of the service.

I am sure there is a better way of doing this, but this is working well for me today.