https://wiki.archlinux.org/title/systemd-networkd#network_fi...
But simple i would not call it...compared to bsd ;)
The vast majority of users control wpa_supplicant indirectly through NetworkManager, so it's not widely known that it can be configured using simple text files. But it can! On Arch linux, the default config file location (for network card wlan0) is: /etc/wpa_supplicant/wpa_supplicant-wlan0.conf.
iwd is similarly straightforward to configure using text files. Using the CLI front-end is typically a nicer experience, since you get to pick the SSID from scan results and you get quick feedback if you mess up the password. But if you want to do it manually, just create one file per wifi network (containing SSID, password, etc) in /var/lib/iwd/.
I tried finding similarly named files, to no avail. Knowing the notorious ADHD of the systemd developership, I wouldn't be surprised if this file is moved, renamed, and uses a different format every six months.
http://manpages.ubuntu.com/manpages/focal/man5/systemd.netwo...
or
find / -name '*.network'
But yeah, BSD's would have them at one place -> /etc ...linux-distro standardization is a terrible mess.
EG Debian's systemd fork puts it in /lib/systemd/network/ (and lots of other network files in /usr/lib/systemd/network/).
/etc/apt/apt.conf.d/
For me the coolest thing about OpenBSD is it’s the simplest OS that is still of practical use (i.e., not counting ones that are purely for research or education). So if you’re curious about how any part of the system works, it’s easy to just dive into /usr/src and figure it out. It’s also entirely configured via simple text files rather than some opaque systemd monstrosity.