What were you trying to do that didn't work?

Red Hat Service Interconnect uses the Compat API to manage Podman and Docker containers.

In podman v5 on RHEL 9, we have noticed that containers created using the Compat API can no longer resolve entries added to /etc/hosts of the host machine (only on RHEL9), but it works fine on CentOS 9 (same version 5.40), Fedora (latest) and Ubuntu.

I have also created an upstream discussion about it earlier, but it was just to provide a small reproducer for Fedora (which is not adding entries to /etc/hosts, but it is resolving them): https://github.com/containers/podman/discussions/25004 .

On the RHEL 9, by downgrading podman to 4.9.4, containers created through the Compat API can resolve those entries (they also show up as part of the /etc/hosts file within the container).

What is the impact of this issue to you?

Some of our customers are currently tied to podman-4.9.4, due to this issue.

Please provide the package NVR for which the bug is seen:

podman-5.4.0-9.el9_6

How reproducible is this bug?:

There is a very simple upstream reproducer available here:
https://github.com/containers/podman/discussions/25004

It is easy to reproduce.

Steps to reproduce

1. Start the podman.socket user level service

systemctl --user enable --now podman.socket

1. Create a sample container using the Compat API

curl -v --unix-socket /run/user/1000/podman/podman.sock \
    -X POST \
    -H "Content-Type: application/json" \
    --data-binary '{"Image":"quay.io/fedora/fedora:41","Cmd": ["tail", "-f", "/dev/null"], "Name":"my-container"}' \
    http:/d/containers/create?name=my-container

1. Start the container

podman start my-container

1. Try to resolve an entry from the /etc/hosts in the host machine

podman exec my-container getent hosts my-host-entry

Expected results

Resolve the host entry.

Actual results

Entry from /etc/hosts in the host machine cannot be resolved.