Unable to access docker Web UI after enabling 'VPN Tunneld access for docker'

[ThatIcyPolarBear]

So here's the problem: I can't access the web ui of my docker application after i set the network type to my vpn provider (mullvad).
I have correctly added a tunnel for Mullvad by downloading a configuration from then and then importing it into unraids build in wireguard and then setting the 'Peer type of access' to 'VPN Tunneld access for do docker'.
When I change the network Type in my docker application to that wireguard tunnel I can't access the web UI anymore.
I've searched around reddit and google but can't seem to find a solution that works for me.
Here are some pictures of my settings:

It MIght Be importont to add that the local ip of my server is 192.168.1.20 (default gateway 192.168.1.1) and that I don't really understand subnetting, even after looking it up a few times.
I would appreciate any help.

[TurkeyPerson]

Not clear what you are trying to do. I thought this was to set up WG to vpn into your server. If you're using an external VPN to go to another network then you won't be able to access the UI.

[ThatIcyPolarBear]

You can and I have set up a wg tunnel to vpn into my server (the 'remote acces to server' connection type), but I also want to have docker applications go through a vpn provider like for example for torrenting. The manual sais that this can be achieved via the 'VPN tunneld access (for docker)' connection type. More info of outgoing VPN connections can be found here. I followed the guide included in the manual and got my config directly from mullvad. On my own windows laptop I can enable a setting in the mullvad app so that I'm able to access LAN adresses. This setting however doesn't seem to be present in either the mullvad wireguard config generator, or the unraid settings. Since the mullvad app uses wireguard I can't understand why I can't enable lan connections in the unraid settings. It might have something to do with allowed IP's setting but I tried lot's of different combinations there and none of them worked.

[ThatIcyPolarBear]

I managed to finally solve the issue! I also found a link to this forum thread which add some important details the manual just doesn't mention.

So first of all to fix the issue you want to edit your container and add a port. Specifically the port of your web ui. I found out that some containers already have this at default (like linuxserver's firefox) and some (like the official plex media server) don't. Which was the reason why I couldn't access the plex web ui

If you add the port it should look something like this. You probably want to change the port tho.

After that you can access the web ui without issue but if you go to any dns leak test you will probably find that your leaking dns.
The mentioned thread above mentions how to fix that. Basically you want to add a '--dns=<DNS>' to the extra parameters setting which you can change by going into advanced view. Then replace the <DNS> with any dns provider that isn't your isp's. You can use google's: 8.8.8.8 or preferably the one which came with your vpn config. (The DNS in the vpn config doesn't get imported when you import a config) I would  read the rest of the forum thread just to be safe tho.
IMPORTANR NOTE: setting the dns in the vpn settings ('peer dns server') doesn't work. You HAVE to do it via the extra parameters otherwise your dns will leak!

Edited January 22, 2023 by ThatIcyPolarBear