Variable introspection

A common set of problems that are encountered when developing Ansible playbooks is the improper use, or invalid assumption, of the value of variables. This is particularly common when registering the results of one task in a variable, and later using that variable in a task or template. If the desired element of the result is not accessed properly, the end result will be unexpected, or perhaps even harmful.

To troubleshoot improper variable usage, an inspection of the variable value is the key. The easiest way to inspect a variable's value is with the ansible.builtin.debug module. The ansible.builtin.debug module allows the display of freeform text on screen, and as with other tasks, the arguments to the module can take advantage of the Jinja2 template syntax as well. Let's demonstrate this usage by creating a sample play that executes a task, registers the result, and then shows the result in an ansible.builtin.debug statement using...