Hi Ilmo,
I think you also need to run robot from the entry_point.sh so that everything starts in that session, so you probably need to setup a variable to any options to robot.
I can’t find the article I read now, where I got this information, but google “docker robotframework selenium” and you’ll find quite a few examples, you just need to replace the selenium parts with browser library parts.
Also it might be worth googling google “docker robotframework browser” or variations and see if anyone has done it already (but from my quick searches it doesn’t look like it)
This was actually on my todo list but it’s a fair way down the list.
Dave.