feat(decoredirect): add redirectCode field (301|307) and opt-in X-Redirect-By header

[igoramf]

Summary

• Add redirectCode optional field to DecoRedirect CRD — accepts 301 or 307 (kubebuilder enum, validated by API server), defaults to 307. The controller sets nginx.ingress.kubernetes.io/permanent-redirect-code per-Ingress from this value.
• Expose redirectCode in the operator management HTTP API (POST body and GET/LIST response).
• Add opt-in X-Redirect-By response header: when redirect.decoHeader.enabled=true, the Helm chart creates a deco-custom-headers ConfigMap and nginx reads it via add-headers. Value is configurable (redirect.decoHeader.value, default "deco"). A NOTES.txt warning fires if enabled=true but add-headers is not wired.

Notes

• Default change: existing redirects will move from 301 → 307 on next reconcile (kubebuilder injects the default at next API server write). Intentional per the spec, but worth calling out in release notes for SEO-sensitive clients.
• The decoHeader feature requires two values to be set together (redirect.decoHeader.enabled=true + ingress-nginx.controller.config.add-headers); Helm subchart value templating doesn't allow auto-wiring, so the NOTES.txt warning bridges the gap.

Test Plan

• make test passes (all controller + API tests green)
• helm lint chart/ passes
• helm template --set redirect.decoHeader.enabled=true renders deco-custom-headers ConfigMap
• helm template (defaults) renders no deco-custom-headers
• POST /redirects with redirectCode: 301 stores and returns 301
• POST /redirects with redirectCode: 302 returns 422
• POST /redirects without redirectCode defaults to 307

🤖 Generated with Claude Code

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Summary by cubic

Adds an optional redirectCode (301 or 307; default 307) to DecoRedirect, passes it through the HTTP API and controller to set the NGINX per-Ingress redirect code, and adds opt-in custom response headers via Helm. Also ignores values-local.yaml.

• New Features

  • CRD: redirectCode enum (301|307) with default 307; API server validates.
  • Controller: sets nginx.ingress.kubernetes.io/permanent-redirect-code per Ingress.
  • HTTP API: POST accepts redirectCode; GET/LIST return it; invalid values return 422.
  • Helm: opt-in custom response headers via redirect.customHeaders (map) rendering a redirect-response-headers ConfigMap; NOTES.txt shows activation steps and warns if not wired; works with ingress-nginx.
  • Helm generator: generates the custom headers ConfigMap template so it isn’t removed by cleanups.

• Migration

  • Default change: existing redirects move from 301 to 307 on next reconcile.
  • To enable headers: set redirect.customHeaders.enabled=true with redirect.customHeaders.headers, and set ingress-nginx.controller.config.add-headers: "<redirect.namespace>/redirect-response-headers".

^{Written for commit 14f34d4. Summary will update on new commits.}