I've just converted a service that had been using WiringPi to use pigpio instead. Since pigpio requires elevated permissions (which WiringPi did not), I needed to make sure that my service (a Node.js web server, set up in /etc/init.d/myService) runs with root privileges.
"sudo systemctl enable myService" seems to do the trick, but I'm not sure if that's the right way to do this -- it doesn't make too much sense to me, since my service previously appeared to be enabled anyway. This is just something I stumbled upon that works. I'm feeling like maybe this is accidentally getting the job done, but it's not the correct approach.
Most of what I've googled about running a service as root seems to be about totally different service set-ups than what I'm using.
Previously "sudo update-rc.d myService defaults" was enough when I didn't need root privileges.
The full project code for the service set-up is documented here: https://github.com/kshetline/aw-clock/t ... y_pi_setup
And here: https://github.com/kshetline/aw-clock/b ... /README.md