Cheatsheet
Checking configuration of a service
Check logs of a service
Disable a service at boot
Enable a service at boot
Get service settings
List service environment variables
List running services
Remove a service environment variable
Restart a service
Scripts
Set service environment variable
Start a service
Stop a service
System and service managers
https://www.digitalocean.com/community/tutorials/how-to-use-systemctl-to-manage-systemd-services-and-units