In which places and files is it recommended to place variables when using Ansible?

In Ansible, variables can be placed in different locations depending on their scope and purpose:

• Inventory files — variables specific to hosts or groups of hosts, usually defined in inventory files or in directories group_vars/ and host_vars/.
• Playbook — variables can be declared within the playbook in vars or vars_files sections.
• Roles — within roles, variables are placed in roles/<role_name>/vars/ (hardcoded variables) or roles/<role_name>/defaults/ (default variables).
• Variable files — separate YAML files with variables, included via vars_files.
• Environment variables and command line — for temporary overrides.

It is recommended to:

• Store variables related to specific hosts or groups in host_vars and group_vars.
• Use defaults in roles for default values that can be overridden.
• Use vars in roles for mandatory variables that should not be overridden.

This approach ensures ease of maintenance and reusability of configurations.