You need to stop thinking of it as an OS. It's just an easy/lazy way to grab all the dependencies your process may need. Here's a silly analogy: You're trying

You need to stop thinking of it as an OS. It's just an easy/lazy way to grab all the dependencies your process may need. Here's a silly analogy: You're trying to containerize a simple football game. To run the game you need to provide a playing field that meets all the requirements of the rules, your dependencies. You could go through all the rules one by one and write down what is required, like you need a line here of that length, another there that has to be at least x far away, but no more than y, and so forth. After the tedious task of collecting all your dependencies you give it a test run and it all looks good, but then boom the game suddenly stops. Whoops you forgot a dependency and didn't provide the goals, or added the wrong ones. Alternatively you can take the easy route. You know they play regulation football in Ubuntu stadium, so you just take a copy of that. It comes with a lot of overhead - you don't need the ranks, concession stands or parking lots to simply play football without all the faff, but it's included because league football needs it. Edit: When you do take the base image of Ubuntu stadium and docker run it, the default is set to play a game of football, because that's the most likely thing you want to do there. It doesn't activate the media coverage and stadium announcer, doesn't sell tickets and fills up the parking lot because none of that is required to play. You could if you wanted to, but you could also tear it all out and the default game would still run.