computer-playbook/filter_plugins/README.md

Custom Filter Plugins for CyMaIS

This directory contains custom Ansible filter plugins used within the CyMaIS project.

When to Use a Filter Plugin

• Transform values: Use filters to transform, extract, reformat, or compute values from existing variables or facts.
• Inline data manipulation: Filters are designed for inline use in Jinja2 expressions (in templates, tasks, vars, etc.).
• No external lookups: Filters only operate on data you explicitly pass to them and cannot access external files, the Ansible inventory, or runtime context.

Examples

{{ role_name | get_entity_name }}
{{ my_list | unique }}
{{ user_email | regex_replace('^(.+)@.*$', '\\1') }}

When not to Use a Filter Plugin

• If you need to load data from an external source (e.g., file, environment, API), use a lookup plugin instead.
• If your logic requires access to inventory, facts, or host-level information that is not passed as a parameter.

Further Reading

• Ansible Filter Plugins Documentation
• Developing Ansible Filter Plugins