get_docker_networking() matches (and thus excludes) interfaces it shouldn't

[cmsj]

In tools.sh is this line:

https://github.com/binhex/arch-int-vpn/blob/623db6937ba455ba39f4793cb18e1534b321d08a/run/root/tools.sh#L52C22-L52C143

The final grep will exclude any interface with lo in the name, but really it should only be excluding interfaces based on their full name.

Docker has the ability to name network interfaces, which can be very useful for disambiguating which interfaces are connected to which networks, for example:

networks:
  downloaders:
    external: false
    driver: bridge
    name: downloaders
    driver_opts:
      com.docker.network.bridge.name: br-downloaders
      com.docker.network.container_iface_prefix: downloaders

This will result in any container attached to the downloaders network having an interface named downloaders0. You can probably see where this is going already :)

Here is what happens to the command in tools.sh with/without the final grep:

[root@1402fcdd8e21 /]# ip link show | grep -v 'state DOWN' | cut -d ' ' -f 2 | grep -P -o '^[^@:]+'
lo
downloaders0
[root@1402fcdd8e21 /]# ip link show | grep -v 'state DOWN' | cut -d ' ' -f 2 | grep -P -o '^[^@:]+' | grep -P -v "lo"
[root@1402fcdd8e21 /]#

I would suggest that a better version of that grep would be:

[root@1402fcdd8e21 /]# ip link show | grep -v 'state DOWN' | cut -d ' ' -f 2 | grep -P -o '^[^@:]+' | grep -P -v "^(lo|tun0)$"
downloaders0