Ansible tips

1. set_stats must have data

   set_stats:
    data:
        failure_reason: "Duplicate."
   

2. Cannot loop on a block

3. debug cannot show up in a play, but only in tasks

4. set_stats variables cannot be used within same playbook, but only in other playbooks

5. set_stats/set_fact cannot partially change a dictionary, the correct way is to use “combine” filter

6. unless in a role, include/import cannot be inside tasks, but only outside

7. import is static, include is dynamic

8. vars in a task is NOT recognizable in the where clause, but loop_control var is.
   vars in a task is recognizable in the loop clause

9. variable scope (e.g. set_fact) covers all the descendant and ancestor playbooks included.
   Therefore vars in descendant/ancestor playbooks are alwasy overwritten by parent/offspring set_fact due to precedence.