The process of defining a collection of hosts to Ansible is called the inventory. A host can be defined using its Fully Qualified Domain Name (FQDN), local hostname, and/or its IP address. Since Ansible uses SSH to connect to the hosts, you can provide any alias for the host that the machine where Ansible is installed can understand.
Ansible expects the inventory file to be in an INI-like format and named
hosts. By default, the inventory file is usually located in the /etc/ansible directory and will look something similar to this:
athena.example.com [ocean] aegaeon.example.com ceto.example.com [air] aeolus.example.com zeus.example.com apollo.example.com
Tip
Personally, I have found the default inventory file to be located in different places depending on the operating system Ansible is installed on. With that point, I prefer to use the –i command line option when executing a playbook. This allows me to designate the specific hosts file location. A working example will...