inventory (Ansible)

The list of machines Ansible manages and how to reach each one: a name, then variables such as ansible_host, ansible_user, or ansible_connection=local for the machine Ansible runs on. In INI form one host is one line; the default file is /etc/ansible/hosts, and a project names its own with -i or with inventory = in ansible.cfg. Two things it does not do. It does not check that a host exists: a pattern matching nothing prints a warning and exits 0, so a typo in a host name is not an error. And it installs nothing on the machine it lists: the connection is plain SSH, and the target needs only python3, which Ubuntu Server already has. ansible-inventory --list shows the inventory as Ansible reads it, variables resolved and hosts grouped — which is what to trust over what you think you typed.