[middleware-manager] Document External Middlewares feature (Traefik-native middleware assignment)

[strausmann]

Summary

External Middlewares is a significant feature that allows assigning Traefik-native (non-MM-managed) middlewares to resources. It has 3 dedicated API endpoints and is accessible from the Resource detail view in the UI — but is completely undocumented.

Source

Gap analysis: docs/upstream-contributions/middleware-manager/docs-analyse.md (Section 3.1)

What Needs to Be Documented

Feature Description

External Middlewares allows users to reference middlewares that exist in Traefik's own configuration (not created through middleware-manager) and attach them to resources managed by MM. This is important for:

• Using Traefik plugins that MM doesn't manage
• Using CrowdSec bouncer middleware
• Referencing middlewares from other configuration sources

API Endpoints

• GET /api/resources/:id/external-middlewares — List external middlewares for a resource
• POST /api/resources/:id/external-middlewares — Assign an external middleware
• DELETE /api/resources/:id/external-middlewares — Remove an external middleware assignment

UI Location

Accessible from the Resource detail view (ResourceDetail.tsx)

Also Missing from Resources UI Guide

The current ui-guides/resources.mdx also doesn't mention:

• Per-resource TLS Hardening toggle
• Per-resource Secure Headers toggle
• These should be added alongside the external middlewares documentation

Acceptance Criteria

• External Middlewares are documented: what they are, when to use them, how to assign/remove
• At least one practical example (e.g. assigning a CrowdSec bouncer middleware)
• Difference between MM-managed middlewares and external middlewares is clearly explained
• ui-guides/resources.mdx updated to include: external middlewares, per-resource TLS hardening toggle, per-resource secure headers toggle
• API endpoints documented (can reference the API overview)

Effort Estimate

S (1–2 hours)

[github-actions]

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