Do not register API Middleware with validator gateway (#9055)

* Do not register API Middleware with validator gateway

* add nil checker

* revert bool

* nil check

Co-authored-by: Raul Jordan <raul@prysmaticlabs.com>
Co-authored-by: prylabs-bulldozer[bot] <58059840+prylabs-bulldozer[bot]@users.noreply.github.com>

beacon-chain/rpc/apimiddleware/endpoint_factory.go

@@ -9,6 +9,10 @@ import (
 type BeaconEndpointFactory struct {
 }
 
+func (f *BeaconEndpointFactory) IsNil() bool {
+	return f == nil
+}
+
 // Paths is a collection of all valid beacon chain API paths.
 func (f *BeaconEndpointFactory) Paths() []string {
 	return []string{

shared/gateway/api_middleware.go

@@ -23,6 +23,7 @@ type ApiProxyMiddleware struct {
 type EndpointFactory interface {
 	Create(path string) (*Endpoint, error)
 	Paths() []string
+	IsNil() bool
 }
 
 // Endpoint is a representation of an API HTTP endpoint that should be proxied by the middleware.

shared/gateway/gateway.go

@@ -231,7 +231,9 @@ func (g *Gateway) Start() {
 		}
 	}()
 
-	go g.registerApiMiddleware()
+	if g.apiMiddlewareAddr != "" && g.apiMiddlewareEndpointFactory != nil && !g.apiMiddlewareEndpointFactory.IsNil() {
+		go g.registerApiMiddleware()
+	}
 }
 
 // Status of grpc gateway. Returns an error if this service is unhealthy.

shared/gateway/gateway_test.go

@@ -81,6 +81,7 @@ func TestValidatorGateway_StartStop(t *testing.T) {
 	validatorGateway.Start()
 	go func() {
 		require.LogsContain(t, hook, "Starting gRPC gateway")
+		require.LogsDoNotContain(t, hook, "Starting API middleware")
 	}()
 
 	err := validatorGateway.Stop()