Add documentation on how to add load balancer attributes to Ingress Class Params (kubernetes-sigs#2321)

* Add doc on how to implement loadBalancerAttributes

* Update docs/guide/ingress/ingress_class.md

Co-authored-by: Kishor Joshi <[email protected]>

* Update docs/guide/ingress/ingress_class.md

Co-authored-by: Kishor Joshi <[email protected]>

Co-authored-by: Kishor Joshi <[email protected]>

Author: 2 people

docs/guide/ingress/ingress_class.md

@@ -91,6 +91,19 @@ You can use IngressClassParams to enforce settings for a set of Ingresses.
       group:
         name: my-group
     ```
+    - with loadBalancerAttributes
+    ```
+    apiVersion: elbv2.k8s.aws/v1beta1
+    kind: IngressClassParams
+    metadata:
+        name: awesome-class
+    spec:
+      loadBalancerAttributes:
+      - key: deletion_protection.enabled
+        value: "true"
+      - key: idle_timeout.timeout_seconds
+        value: "120"
+    ```
 
 ### IngressClassParams specification
 
@@ -142,3 +155,12 @@ Cluster administrators can use `tags` field to specify the custom tags for AWS r
     1. controller-level flag `--default-tags` will have the highest priority.
     2. `spec.tags` in IngressClassParams will have the middle priority.
     3. `alb.ingress.kubernetes.io/tags` annotation will have the lowest priority.
+
+#### spec.loadBalancerAttributes
+
+`loadBalancerAttributes` is an optional setting.
+
+Cluster administrators can use `loadBalancerAttributes` field to specify the [Load Balancer Attributes](https://docs.aws.amazon.com/elasticloadbalancing/latest/application/application-load-balancers.html#load-balancer-attributes) that should be applied to the load balancers that belong to this IngressClass. You can specify the list of load balancer attribute name and the desired value in the `spec.loadBalancerAttributes` field.
+
+1. If `loadBalancerAttributes` is set, the attributes defined will be applied to the load balancer that belong to this IngressClass. If you specify invalid keys or values for the load balancer attributes, the controller will fail to reconcile ingresses belonging to the particular ingress class.
+2. If `loadBalancerAttributes` un-specified, Ingresses with this IngressClass can continue to use `alb.ingress.kubernetes.io/load-balancer-attributes` annotation to specify the load balancer attributes.