The previous list of priority ordering is obviously helpful when writing Ansible playbooks, and, in most cases, it is apparent that variables should not clash. For example, a task var clearly wins over a play var, and all tasks and indeed plays are unique. Similarly, all hosts in the inventory will be unique, so again, there should be no clash of variables with the inventory either.
There is, however, one exception to this – inventory groups. A one-to-many relationship exists between hosts and groups, and, as such, any given host can be a member of one or more groups. Let's suppose that the following code is our inventory file by way of example:
[frontend]host1.example.comhost2.example.com[web:children]frontend ...
