apis: add GatewayClassConditionReason Unsupported (kubernetes-sigs#3048)

* apis: add GatewayClassConditionReason Invalid

Clarify description for when GatewayClassConditionReason
InvalidParameters should be preferred.

* doc: clarify expected behavior for bad reference in GatewayClass ParametersRef

* docs: GatewayClass SHOULD be rejected with InvalidParameters reason

* apis: switch from Invalid reason to Unsupported

* fixup codegen and yamllint

---------

Co-authored-by: Mike Morris <1149913+mikemorris@users.noreply.github.com>

apis/v1/gatewayclass_types.go

@@ -93,8 +93,10 @@ type GatewayClassSpec struct {
 	// or an implementation-specific custom resource. The resource can be
 	// cluster-scoped or namespace-scoped.
 	//
-	// If the referent cannot be found, the GatewayClass's "InvalidParameters"
-	// status condition will be true.
+	// If the referent cannot be found, refers to an unsupported kind, or when
+	// the data within that resource is malformed, the GatewayClass SHOULD be
+	// rejected with the "Accepted" status condition set to "False" and an
+	// "InvalidParameters" reason.
 	//
 	// A Gateway for this GatewayClass may provide its own `parametersRef`. When both are specified,
 	// the merging behavior is implementation specific.
@@ -162,6 +164,7 @@ const (
 	// Possible reasons for this condition to be False are:
 	//
 	// * "InvalidParameters"
+	// * "Unsupported"
 	// * "UnsupportedVersion"
 	//
 	// Possible reasons for this condition to be Unknown are:
@@ -176,9 +179,10 @@ const (
 	// true.
 	GatewayClassReasonAccepted GatewayClassConditionReason = "Accepted"
 
-	// This reason is used with the "Accepted" condition when the
-	// GatewayClass was not accepted because the parametersRef field
-	// was invalid, with more detail in the message.
+	// This reason is used with the "Accepted" condition when the GatewayClass
+	// was not accepted because the parametersRef field refers to a nonexistent
+	// or unsupported resource or kind, or when the data within that resource is
+	// malformed.
 	GatewayClassReasonInvalidParameters GatewayClassConditionReason = "InvalidParameters"
 
 	// This reason is used with the "Accepted" condition when the
@@ -187,6 +191,11 @@ const (
 	// GatewayClass.
 	GatewayClassReasonPending GatewayClassConditionReason = "Pending"
 
+	// This reason is used with the "Accepted" condition when the GatewayClass
+	// was not accepted because the implementation does not support a
+	// user-defined GatewayClass.
+	GatewayClassReasonUnsupported GatewayClassConditionReason = "Unsupported"
+
 	// Deprecated: Use "Pending" instead.
 	GatewayClassReasonWaiting GatewayClassConditionReason = "Waiting"
 )