Adds Service Type to PolicyTargetReference API Docs (#3199)

Previously, only a Gateway resource was defined as a supported
attachment type. This PR updates the API docs to include a Service
as a supported type and also fixes an incorrect link to Gateway API
documentation.

Signed-off-by: Daneyon Hansen <daneyon.hansen@solo.io>

Author: danehans

extensions/v1alpha1/wasm.pb.go

@@ -250,12 +250,13 @@ message WasmPlugin {
   // $hide_from_docs
   istio.type.v1beta1.PolicyTargetReference targetRef = 15;
 
-  // Optional. The targetRef specifies the gateway the policy should be
-  // applied to. The targeted resource specified will determine which
-  // workloads the policy applies to.
+  // Optional. The targetRefs specifies a list of resources the policy should be
+  // applied to. The targeted resources specified will determine which workloads
+  // the policy applies to.
   //
   // Currently, the following resource attachment types are supported:
   // * `kind: Gateway` with `group: gateway.networking.k8s.io` in the same namespace.
+  // * `kind: Service` with `""` in the same namespace. This type is only supported for waypoints.
   //
   // If not set, the policy is applied as defined by the selector.
   // At most one of the selector and targetRefs can be set.

extensions/v1alpha1/wasm.pb.html

@@ -849,12 +849,13 @@ message EnvoyFilter {
   // workloads in any namespace.
   WorkloadSelector workload_selector = 3;
 
-  // Optional. The targetRef specifies the gateway the policy should be
-  // applied to. The targeted resource specified will determine which
-  // workloads the policy applies to.
+  // Optional. The targetRefs specifies a list of resources the policy should be
+  // applied to. The targeted resources specified will determine which workloads
+  // the policy applies to.
   //
   // Currently, the following resource attachment types are supported:
   // * `kind: Gateway` with `group: gateway.networking.k8s.io` in the same namespace.
+  // * `kind: Service` with `""` in the same namespace. This type is only supported for waypoints.
   //
   // If not set, the policy is applied as defined by the selector.
   // At most one of the selector and targetRefs can be set.

extensions/v1alpha1/wasm.proto

@@ -272,12 +272,13 @@ message AuthorizationPolicy {
   // $hide_from_docs
   istio.type.v1beta1.PolicyTargetReference targetRef = 5;
 
-  // Optional. The targetRef specifies the gateway the policy should be
-  // applied to. The targeted resource specified will determine which
-  // workloads the policy applies to.
+  // Optional. The targetRefs specifies a list of resources the policy should be
+  // applied to. The targeted resources specified will determine which workloads
+  // the policy applies to.
   //
   // Currently, the following resource attachment types are supported:
   // * `kind: Gateway` with `group: gateway.networking.k8s.io` in the same namespace.
+  // * `kind: Service` with `""` in the same namespace. This type is only supported for waypoints.
   //
   // If not set, the policy is applied as defined by the selector.
   // At most one of the selector and targetRefs can be set.

networking/v1alpha3/envoy_filter.pb.go

@@ -250,12 +250,13 @@ message RequestAuthentication {
   // $hide_from_docs
   istio.type.v1beta1.PolicyTargetReference targetRef = 3;
 
-  // Optional. The targetRef specifies the gateway the policy should be
-  // applied to. The targeted resource specified will determine which
-  // workloads the policy applies to.
+  // Optional. The targetRefs specifies a list of resources the policy should be
+  // applied to. The targeted resources specified will determine which workloads
+  // the policy applies to.
   //
   // Currently, the following resource attachment types are supported:
   // * `kind: Gateway` with `group: gateway.networking.k8s.io` in the same namespace.
+  // * `kind: Service` with `""` in the same namespace. This type is only supported for waypoints.
   //
   // If not set, the policy is applied as defined by the selector.
   // At most one of the selector and targetRefs can be set.