Wireguard Tunnel for Docker Containers - Tunnel Containers to a VPS with public IPV4

Hi, 

I have following issue: I don't have a public IPV4-Address but want to run some servers. I rented a VPS with a public IPV4 and successfully forwarded ports like 8080 on a VM to the VPS.

I tested a setup which allows me to tunnel let's say a nginx-server from my Unraid VM via my VPS (with a public ipv4-address) and make it accessible via the VPS's IP like "123.123.123.123:80". I used this tutorial and it works great: https://gist.github.com/Quick104/d6529ce0cf2e6f2e5b94c421a388318b

I can access the Server running on the VM (with wireguard inside) on my UnRaid-Server.

Now, I want to simple use this method to access my docker containers. So I set up the build in Wireguard-Feature in unraid. The container is able to connect to the internet via the VPS IP. All port forwardings are set on the VPS as always. But I can't access let's say port 8080 on the VPS Ip. Curious: When I run a port scan, it shows me a active port 8080. It looks like the webpage is loading, but it's not.

There must be a problem between the wireguard endpoint on my unraid and the container.

Following IPTables are set on the VPS (The VPS Setup shouldn't be the problem):

iptables -A FORWARD -i eth0 -o wg0 -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT &
iptables -A FORWARD -i wg0 -o eth0 -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT &

iptables -A FORWARD -i eth0 -o wg0 -p tcp --syn --dport 8080 -m conntrack --ctstate NEW -j ACCEPT &
iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 8080 -j DNAT --to-destination 10.66.66.2 &
iptables -t nat -A POSTROUTING -o wg0 -p tcp --dport 8080 -d 10.66.66.2 -j SNAT --to-source 10.66.66.1 &

These Iptables work when running the tunnel directly between a VM (KVM) and the VPS.

I also tried the docker-container gluetun-vpn. It produces the exact same issue. I can't connect to ports like 8080 via the "vpn tunneled access for docker".

Is there anyone having the same issue or solved it?

Thanks Unraid-Community!