Identify when using net="container" when container refer to a container using net="host" and use nethogs in this case too.
We now assume
The device to monitor are all the ones available to the container, that should be all the available interface to the host, since we don't limit them. Example of command: nethogs -d 1 docker0 eth0 lo.
Investigate whether it is possible to get only the ones used by the monitored containers, to reduce the collected data and the load. Now we collect all of them, so we get all the data.