OCI/ROCK Container: Avahi sees printer as remote service not as local service

When running the (immutable) OCI container of ipp-usb, from PR #106, from https://github.com/im0vishal/ipp-usb/tree/immutable-ipp-usb, commit 44b2745f ("Updated ReadMe to include runtime flags for data persistence"), started with the command lines

sudo docker volume create ipp-usb-data
sudo docker run -d --network host -v /dev/bus/usb:/dev/bus/usb:ro -v ipp-usb-data:/var/lib/ipp-usb --device-cgroup-rule='c 189:* rmw' --name ipp-usb ipp-usb:latest

the avahi-daemon on the host system sees ipp-usb as a remote service and not as a local service. So running ippfind --local does not list the printer but ippfind --remote lists it.

Especially client tools then do not replace the network host name (XXX.local) by localhost, and if ipp-usb is providing the printer only on the local machine (lo network interface) the printer cannot be accessed as the URI ipp://XXX.local:60000/ipp/print is advertised and used, while ipp://localhost:60000/ipp/print works.

This can be caused by the container running its own avahi-daemon and so the host's avahidaemon receiving the service from the container's avahi-daemon and not directly.

In avahi (I am using 0.8.0), the function avahi_server_is_service_local() in the file avahi-core/server.c of the Avahi source code is actually determining whether a service is local or not.

The function is left by the return 0; in these lines:

    e = find_entry(s, interface, protocol, key);
    avahi_key_unref(key);
    if (!e)
        return 0;

and therefore the service is see as not local. This I found out by applying the attached patch to the Avahi source code and looking for XXX in the /var/log/syslog file and I saw XXX6 but not XXX10 right afterwards.

check-local.patch.txt

Reproduce the issue with the Docker command and inspect the attached check-local.patch.txt alongside avahi-core/server.c, especially avahi_server_is_service_local(). Compare the host and container Avahi behavior using ippfind --local and ippfind --remote; done means the printer is recognized as a local service and advertised with the usable local URI.