bgpdisco: nameservice: mechanism to set main IP of the device is broken

[spolack]

In order to detect the main IP, which is announced as the nodes hostname, there is simple procedure foreseen.

While looping over all Interfaces with their IPs, it stores the first seen IPv4 and IPv6 address. Same applies for Loopback IPs, it stores first seen IPv4 loopback IP and first IPv6 address.

Afterwards, it checks if loopback IPv4/IPv6 is set, if not (because it has no IP configured), it resorts to first IPv4, first IPv6 for configuring the main dns record.

The Loop iterates over a dictionary with IP as key and Devices as value. In case of a Loopback having the same IP as a another interface (which is allowed, as a interface can have the first subnet of the loopback network), it is colliding and leaving loopback or the device other IP/Device combination unconfigured.

The dictionary is produced in get_interfaces_with_ip():

falter-packages/packages/bgpdisco/nameservice.uc

Line 30 in fcb9e32

result[split(i.address, '/')[0]] = i.dev;

And the resulting dictionary is consumed in https://github.com/freifunk-berlin/falter-packages/blob/main/packages/bgpdisco/nameservice.uc#L57-L87