If you use commercial VPN, you may have noticed they all provide WireGuard configurations in the wg-quick format, this is not suitable for an easy use in OpenBSD.
As I currently work a lot for a VPN provider, I often have to play with configurations and I really needed a script to ease my work.
I made a shell script that turns a wg-quick configuration into a hostname.if compatible file, for a full integration into OpenBSD. This is practical if you always want to connect to a given VPN server, not for temporary connections.
OpenBSD manual pages: hostname.if
Sourcehut project: wg-quick-to-hostname-if
It is really easy to use, download the script and mark it executable, then run it with your wg-quick configuration as a parameter, it will output the hostname.if file to the standard output.
wg-quick-to-hostname-if fr-wg-001.conf | doas tee /etc/hostname.wg0
In the generated file, it uses a trick to dynamically figure the current default route which is required to keep a non-vpn route to the VPN gateway.
When I shared my script on mastodon, Carlos Johnson shared their own script which is pretty cool and complementary to mine.
If you prefer to establish a VPN for a limited session, you may want to take a look at his script.
Carlos Johnson GitHub: file-wg-sh gist
If you need your WireGuard VPN to be leakproof (= no network traffic should leave the network interface outside the VPN if it's not toward the VPN gateway), you should absolutely do the following:
Older blog post: WireGuard and rdomains
OpenBSD's ability to configure WireGuard VPNs with ifconfig has always been an incredible feature, but it was not always fun to convert from wg-quick files. But now, using a commercial VPN got a lot easier thanks to a few piece of shell.