Sometimes, the logging and inspection of variable data is not enough to troubleshoot a problem. When this happens, it can be necessary to interactively debug the playbook, or to dig deeper into the internals of Ansible code. There are two main sets of Ansible code: the code that runs locally on the Ansible host, and the module code that runs remotely on the target host.
Debugging code execution
Playbook debugging
Playbooks can be interactively debugged by using an execution strategy that was introduced in Ansible 2.1, the debug strategy. If a play uses this strategy, when an error state is encountered an interactive debugging session starts. This interactive session can be used to display variable data, display task arguments...