ok nice question -
Ansible inherently provides idempotence through many of its built-in modules. This core principle means that when an Ansible task is executed, it makes the necessary changes to bring the target node to the desired state, and subsequent executions of the same task on that node will not cause any further modifications if the desired state is already achieved.
While idempotence is a characteristic of the vast majority of Ansible modules, some, such as command and shell, do not possess this behavior natively. When using these modules, it becomes necessary to design the tasks in a way that manually enforces idempotence. Exceptions to Ansible's inherent idempotence can also occur, for instance, when a service module's state attribute is set to restarted. In such cases, the service (e.g., HTTPD) will be restarted every time the task runs, violating idempotence and leading to unnecessary operations. To address such scenarios, Ansible offers tools like handlers to help maintain idempotency. Similarly, features like conditional execution when, changed_when, and failed_when provide further mechanisms within Ansible to ensure idempotent behavior.
