Re: Connecting back to the host through a dummy veth interface

[Stefano Brivio <sbrivio@redhat.com>]

Hi Felix,

On Thu, 18 Dec 2025 13:32:36 +0100
Felix Rubio <felix@kngnt.org> wrote:

> Hi everybody,
> 
> I am trying to run a number of rootless podman pods and containers by different 
> users, while still being able to talk to each other. To this end I am creating 
> a dummy veth interface and publishing all the exposed ports there (this works: 
> I can communicate from other host services with those containers), and I am 
> also trying to set that dummy veth interface as the default gateway for the 
> pods/containers (with the expectation that then they will be able to reach 
> each other). However, this is not working... and I am pretty lost.
> 
> For example, I am running the following command, trying to connect a ldap 
> client container to a ldap server container, unsuccessfully.
> 
> podman run --rm --dns=10.255.255.1 --network=pasta:--outbound-
> if4=cluster_dns0,--gateway=10.255.255.1 --add-host=ldap.host.internal:host-gateway sh -c "ip add && ip route && ldapwhoami -H ldaps://
> ldap.host.internal:1636"
> 
> Is this something impossible to do, or am I doing something wrong?

Sorry, I'm a bit swamped at the moment, and I plan to get back to you
in a bit, but meanwhile, I think the dummy veth trick is unnecessarily
complicated.

I think you could simply connect "to the host" and redirect from there
to the containers by means of mapped ports. See:

  https://blog.podman.io/2024/10/podman-5-3-changes-for-improved-networking-experience-with-pasta/

for a couple of details. But I'll try to come up with a full example
next.

-- 
Stefano