Searching Dockerhub for ‘ubuntu-sshd’ will turn up many options. In my case I’ll use this one:

<https://hub.docker.com/r/rastasheep/ubuntu-sshd>

Pull the docker image as stated in the directions on the page.

Start a container (mine will be named ssh_server) and map port 9000 to port 22.

docker run -d --name ssh_server -p 9000:22 rastasheep/ubuntu-sshd

Open Putty and SSH in with the username root and password root. (You’ll find this info on the Dockerhub page!)