The Docker file used to create the ubuntu-ssh-enabled Docker image is located here.

https://github.com/mmumshad/ubuntu-ssh-enabled 

Run the container:

docker run -d mmumshad/ubuntu-ssh-enabled

Identify the Internal IP

docker inspect <container-id-name>

SSH

ssh <container-ip>

Username: root

Password: Passw0rd

It is based on the Docker documentation here:

https://docs.docker.com/engine/examples/running_ssh_service/