Suppose you have a Dockerfile ending with
ENTRYPOINT [ "nethogs"] CMD ["wlan0"]
if you build this image with a
docker built -t inspector .
launch the image built with such a Dockerfile with a command such as
docker run -it --net=host --rm inspector
,nethogs will monitor the interface named wlan0
Now if you want to monitor the interface eth0 (or wlan1, or ra1...), you will do something like
docker run -it --net=host --rm inspector eth0
or
docker run -it --net=host --rm inspector wlan1