To login to a Docker container you can run the following command:
docker exec -it your_container_name bash
Once you have logged into the container you will need install your favourite editor such as Nano or Vim.
apt-get update
apt-get install nano
When trying to edit a file you might encounter the following error:
Error opening terminal: unknown.
This is a known bug in Docker and can be solved by running the following command:
export TERM=xterm