Domain as endpoint when using wireguard with network namespaces

[Waishon <waishon009@gmail.com>]

Hey there,

I'm currently trying to setup a wireguard-tunnel inside a
network-namespace as descriped in the documentation, which fails when
using a domain as endpoint:
https://www.wireguard.com/netns/

First I've created the wireguard interface inside the birth-namespace
of the host using "ip link add wg0 type wireguard". Then I moved the
wg0 interface to the newly created network namespace, which doesn't
have any network interfaces and network connections beside the
loopback interface.

Then I configured the wg0 interface inside the network namespace using
    wg set "INTERFACE_NAME" \
        private-key <SECRET \
        peer "PEER" \
        endpoint vpn.example.com:51820 \
        persistent-keepalive 25 \
        allowed-ips ::/0

This however results in a "Temporary failure in name resolution:
`vpn.example.com:51820'. Trying again in 1.00 seconds..." error
message, which makes sense, because the wireguard-tool tries to call
getaddrinfo inside the network namespace. The namespace doesn't have
an internet connection and the lookup fails.
https://github.com/WireGuard/wireguard-tools/blob/96e42feb3f41e2161141d4958e2637d9dee6f90a/src/config.c#L242

As a user I would expect that the wg-tool does the lookup in the
birth-namespace of the interface and not inside the newly created
network namespace.

What is the recommended solution to resolve an domain endpoint when
using network namespaces and wireguard? Just manually lookup the
domain in the birth-namespace and use the ip as endpoint? The
implementation however would be quiete hacky to make it properly work
with IPv4 and IPv6.