From 80391efa7ecc1aead27c91da8ccabf5c2157c4fe Mon Sep 17 00:00:00 2001
From: Harry Bagdi <harrybagdi@gmail.com>
Date: Fri, 26 Mar 2021 13:34:46 +0530
Subject: [PATCH] KEP-2365: documentation for namespace-scoped parameters
 reference

---
 .../docs/concepts/services-networking/ingress.md   | 14 +++++++++++++-
 .../command-line-tools-reference/feature-gates.md  |  4 ++++
 .../service/networking/namespaced-params.yaml      | 12 ++++++++++++
 3 files changed, 29 insertions(+), 1 deletion(-)
 create mode 100644 content/en/examples/service/networking/namespaced-params.yaml

diff --git a/content/en/docs/concepts/services-networking/ingress.md b/content/en/docs/concepts/services-networking/ingress.md
index 7a189a401b..fe09b9a8e8 100644
--- a/content/en/docs/concepts/services-networking/ingress.md
+++ b/content/en/docs/concepts/services-networking/ingress.md
@@ -220,7 +220,19 @@ of the controller that should implement the class.
 {{< codenew file="service/networking/external-lb.yaml" >}}
 
 IngressClass resources contain an optional parameters field. This can be used to
-reference additional configuration for this class.
+reference additional implementation-specific configuration for this class.
+
+#### Namespace-scoped parameters
+
+{{< feature-state for_k8s_version="v1.21" state="alpha" >}}
+
+`Parameters` field has a `scope` and `namespace` field that can be used to
+reference a namespace-specific resource for configuration of an Ingress class.
+`Scope` field defaults to `Cluster`, meaning, the default is cluster-scoped
+resource. Setting `Scope` to `Namespace` and setting the `Namespace` field
+will reference a paramters resource in a specific namespace:
+
+{{< codenew file="service/networking/namespaced-params.yaml" >}}
 
 ### Deprecated annotation
 
diff --git a/content/en/docs/reference/command-line-tools-reference/feature-gates.md b/content/en/docs/reference/command-line-tools-reference/feature-gates.md
index 2c181ca331..2bde94270e 100644
--- a/content/en/docs/reference/command-line-tools-reference/feature-gates.md
+++ b/content/en/docs/reference/command-line-tools-reference/feature-gates.md
@@ -124,6 +124,7 @@ different Kubernetes components.
 | `HPAScaleToZero` | `false` | Alpha | 1.16 | |
 | `HugePageStorageMediumSize` | `false` | Alpha | 1.18 | 1.18 |
 | `HugePageStorageMediumSize` | `true` | Beta | 1.19 | |
+| `IngressClassNamespacedParams` | `false` | Alpha | 1.21 | |
 | `IPv6DualStack` | `false` | Alpha | 1.15 | 1.20 |
 | `IPv6DualStack` | `true` | Beta | 1.21 | |
 | `KubeletCredentialProviders` | `false` | Alpha | 1.20 | |
@@ -642,6 +643,9 @@ Each feature gate is designed for enabling/disabling a specific feature:
   immutable for better safety and performance.
 - `IndexedJob`: Allows the [Job](/docs/concepts/workloads/controllers/job/)
   controller to manage Pod completions per completion index.
+- `IngressClassNamespacedParams`: Allow namespace-scoped parameters reference in
+  `IngressClass` resouce. This feature adds two fields - `Scope` and `Namespace`
+  to `IngressClass.spec.parameters`.
 - `IPv6DualStack`: Enable [dual stack](/docs/concepts/services-networking/dual-stack/)
   support for IPv6.
 - `KubeletConfigFile` (*deprecated*): Enable loading kubelet configuration from
diff --git a/content/en/examples/service/networking/namespaced-params.yaml b/content/en/examples/service/networking/namespaced-params.yaml
new file mode 100644
index 0000000000..dd56724787
--- /dev/null
+++ b/content/en/examples/service/networking/namespaced-params.yaml
@@ -0,0 +1,12 @@
+apiVersion: networking.k8s.io/v1
+kind: IngressClass
+metadata:
+  name: external-lb
+spec:
+  controller: example.com/ingress-controller
+  parameters:
+    apiGroup: k8s.example.com
+    kind: IngressParameters
+    name: external-lb
+    namespace: external-configuration
+    scope: Namespace