Hey @Ruby, You can indeed spin-up multiple docker hosts using the "docker machine" tool, but first and foremost you need to install docker-machine on your ubuntu machine. Firstly make sure if docker is installed and then check if docker-machine is installed previously if not, download the Docker Machine binary and extract it to your PATH.You could do this by using the following command:
$ base=https://github.com/docker/machine/releases/download/v0.16.0 &&
curl -L $base/docker-machine-$(uname -s)-$(uname -m) >/tmp/docker-machine &&
sudo install /tmp/docker-machine /usr/local/bin/docker-machine
Check the installation by displaying the Machine version:
$ docker-machine version
Here's the snapshot of it for your reference: