As an example, the goal is to run container that will download things hosted on the web and run some command DURING a docker launches (using ENTRYPOINT to run the command). FROMubuntuRUN apt-get updateRUN apt-get install -y wgetRUN apt-get install -y unzipRUN apt-get install -y ffmpegRUN wget https://www.cse.fau.edu/~hari/sequences/vid-clips.zipRUN unzip vid-clips.zipENTRYPOINT ["ffmpeg" -i" clip-crf20.mp4" -c:v" libx264" -crf" 36" -c:a" copy" clip-out.mp4"]If you are not root user when you run apt-get install [package], you must confirm yes or no to installation which requires user input.