Variables and Facts

Part of the Ansible course

Write a playbook with the port number, the site name, and the package versions typed directly into the tasks, and it works, once, on the one machine you tested it against. Point the same playbook at a second server with a different IP range or a different amount of memory, and you either edit the file by hand before every run or you accept that it quietly does the wrong thing.

Think about a form letter, the kind a business sends to a thousand customers with the same paragraph structure every time: "Dear ___, your account ending in ___ is due for renewal on ___." Nobody retypes the whole letter for each customer. They write it once with blanks, then fill the blanks in per recipient from a list. A playbook has exactly the same shape as that letter. ...