Generating a dynamic inventory file
In these days of cloud computing and infrastructure-as-code, the hosts you may wish to automate could change on a daily, if not hourly, basis! Keeping a static Ansible inventory up to date could become a full-time job, and hence, in many large-scale scenarios, it becomes unrealistic to attempt to use a static inventory on an ongoing basis.
This is where Ansible’s dynamic inventory support comes in. In short, Ansible can gather its inventory data from just about any executable file (though you will find that most dynamic inventories are written in Python)—the only requirement is that the executable returns the inventory data in a specified JSON format. You are free to create your own inventory scripts if you wish, but thankfully, many have been created already for you to use that cover a multitude of potential inventory sources including Amazon EC2, Microsoft Azure, Red Hat Satellite, Lightweight Directory Access Protocol (LDAP) directories...
