Provided above is a snapshot of a Docker image layers. I currently don’t have the access to the original Docker file. Therefore, I’m trying to re-engineer the docker file by looking through its layers.

As of my understanding, the general way to include unix commands in a docker file for execution is to start it with the Docker RUN command (e.g. RUN apt-get clean). In the provided example, I see that the layer 11, 12, and 13 doesn’t contain RUN command. When I try to directly state unix commands in Docker file, it gives me an error.

I’d like to inquire, how I can achieve this specific implementation in Docker. I also see that this Docker file does not contain any external imports.-i.e. it starts as FROM ubuntu:20:04.