NOTE: You can do other commands such as copy files from the container to your VM, install tools in the container, and anything that can be done on a regular Ubuntu install. For more information, look in the DOCKER DOCUMENTATION.
Assumptions
You are using Ubuntu/Debian-based OS
You have Docker installed
You have a running container
You have access to the docker environment
Get the docker ID and list the containers
Open Ubuntu Terminal
docker ps
This allows you to get a list of all docker containers
The docker ID is the first string of numbers and letters before your container
Enter the docker container
docker exec -it <your container ID> bash
docker exec -it 175cb158268e bash
You can now execute commands in the container just as you could in a regular Ubuntu Server.
