bug: blueos cannot resolve mdns addresses

[rotu]

Bug description

From within the blueos-core image, you cannot resolve hosts published via MDNS.
Additionally, MDNS does not participate in host resolution since blueos-core has a separate /etc/nsswitch.conf from the host OS.

Steps to reproduce

SSH into BlueOS

$ sudo apt install avahi-utils
$ avahi-browse -at

This will show all hosts on the local network.

$ docker exec -it blueos-core apt install avahi-utils
$ docker exec -it blueos-core avahi-browse -at

This will show "Failed to create client object: Daemon not running".

Primary pain point(s)

In SonarView, we assume that window.location is the domain name that expresses the current blueos instance.

This is okay if you use http://blueos but NOT okay if you use http://blueos.local. Note that I expect additional changes will likely have to be made within extensions to make this work.

Additional context

Originally discovered here: https://discuss.bluerobotics.com/t/ping-1d-and-cockpit-standalone-version/17977/7?u=o.o

I cannot ping either blueos-avahi.local. (advertised by avahi-daemon, outside Docker) nor blueos-dan-eth0-1.local. (advertised by Beacon service, from within blueos-core). I can ping both from outside docker.

This should be done with an eye toward how extensions should access local services: #2869

Prerequisites

• I have checked to make sure that a similar request has not already been filed or fixed.

[rotu]

Maybe it's sufficient to mount /var/run/avahi-daemon and /etc/nsswitch.conf from the host OS?

Guess not.