When creating a container in a pod the podname was always set as
the dns entry. This is incorrect when the container is not part
of the pods network namespace. This happend both rootful and
rootless. To fix this check if we are part of the pods network
namespace and if not use the container name as dns entry.
Signed-off-by: Paul Holzinger <paul.holzinger@web.de>
Usage:
```
$ podman network create foo
$ podman run -d --name web --hostname web --network foo nginx:alpine
$ podman run --rm --network foo alpine wget -O - http://web.dns.podman
Connecting to web.dns.podman (10.88.4.6:80)
...
<h1>Welcome to nginx!</h1>
...
```
See contrib/rootless-cni-infra for the design.
Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
