By default, podman bind mounts a "/etc/resolv.conf" file. That prevents
NetworkManager (inside the container) to update the file, which leads to
warnings in the log and certain NM-ci tests won't pass due to that.
Disable handling of "/etc/resolv.conf" in podman. But also pre-deploy a
default resolv.conf, with the google name server 8.8.8.8. I don't
understand why, but even with "--dns=none", writing "/etc/resolv.conf"
while building the container doesn't take effect. Instead, write a
usable "/etc/resolv.conf" from "/etc/rc.d/rc.local".
We need to mount sysfs, so that `ip netns exec` works.
Do that automatically when starting the system container, via rc.local.
While at it, use `podman build --squash-all` to speedup the building of
the container image.
It doesn't actually work inside the root-less container...
Well, it works as far as starting to activate, before it
fails. That is still somewhat useful. So have it there...
