Ansible (https://www.ansible.com/) is a very simple and powerful open source automation tool. While using and creating Ansible playbooks is off-topic for this book, we'll use a very simple playbook to install and configure Docker on a CentOS 7 box. Starting from here, you'll be able to iterate through more complex Ansible playbooks.
To step through this recipe, you will need the following:
$ pip install ansibleor to pick your usual package manager like APT or YUM/DNF)
Because writing complex Ansible playbooks is out of the scope of this ...