How to find out where is a service file in linux?

Question

linux

Let 's say I'm running Apache:
systemctl start apache2
how do I find out where the .service file with its service is located?

Answer 1

systemctl status apache2?

Answer 2

It is better not to edit these files, but to make so-called overrides.

systemctl edit apache2
systemctl cat apache2

The systemctl edit apache2 command will create /etc/systemd/system/apache2.service.d/override.conf
and execute the systemctl daemon-reload itself.
The systemctl cat apache2 command will show which files apache2.service is built from. there may be other files in the /etc/systemd/system/apache2.service.d/ directory.
The advantages are that the distribution file will be updated and will not lose changes during updates.