Check that the package you've installed in the Dockerfile is available in this new container:
You are now inside the nano text editor. Press Ctrl + x to exit it.
Note: Please, note that all the changes made in a container after its creation will be lost when the container exits. To keep data, one needs to use methods to store data outside the container, for example, by using bind mounting.
The fastest way to understand it is by running docker ps --help, either on the board or your computer:
$ docker ps --help
Usage: docker ps [OPTIONS]
-a, --all Show all containers (default shows just running)
-f, --filter filter Filter output based on conditions provided
--format string Pretty-print containers using a Go template
-n, --last int Show n last created containers (includes all states) (default -1)
-l, --latest Show the latest created container (includes all states)
--no-trunc Don't truncate output
-q, --quiet Only display numeric IDs
-s, --size Display total file sizes
Or you can consult the online Docker documentation, which is more comprehensive and has some usage examples: