Domain as endpoint when using wireguard with network namespaces

[Waishon]

Yes I did,

as described this isn't the problem. How should WireGuard resolve the
domain using the DNS server set inside the container, when it doesn't
have an internet connection?

Kind regards


Am Sa., 21. Aug. 2021 um 22:05 Uhr schrieb Marios Makassikis
<mmakassikis at freebox.fr>:
>
> On Tue, Aug 17, 2021 at 11:11 PM Waishon <waishon009 at gmail.com> wrote:
> >
> > 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.
>
> Have you configured a nameserver for your network namespace ?
>
> Normally, that would be /etc/netns/<namespace_name>/resolv.conf (you may
> need to create the subdirectory first).