[bug#41080] [PATCH] doc: cookbook: add entry for Wireguard VPN connection on Guix System

[Brice Waegeneire <brice@waegenei.re>]

Hello Marcin,

Thank you for the patch!

> +@lisp
> +(use-modules (gnu))
> +(use-package-modules vpn)
> +
> +(operating-system
> +;; …
> +(packages
> +    (append (map specification->package
> +        '("wireguard-linux-compat" "wireguard-tools"))
> +    %base-packages)))
> +@end lisp

There is no use to put "wireguard-linux-compat" in the packages field,
instead it should be in the kernel-loadable-modules field to be
loadable by modprobe and an in the kernel-module-loader-service for
being autoloaded at boot with an entry like:
“(simple-service 'wireguard-module kernel-module-loader-service-type
     '("wireguard"))”
Also note that all the above is only necessary with a Linux-libre
kernel >5.6, after that wireguard is built into it.

https://issues.guix.info/issue/41192 should fix the wg-quick issue,
can you try it and update the documentation accordingly. About this
script can you specify that it's a “very quick and dirty bash script”
as wireguard's docs says and that it should probably be avoided except
for testing and such.

Also can you resend the patch as a git-patch instead of a plain diff,
you can find the related guidelines in the manual[0].

[0]: 
https://guix.gnu.org/manual/en/html_node/Submitting-Patches.html#Submitting-Patches

Cheers,
- Brice