Add limit-request-status-code option (#2001)

* Add support for limit_req_status

* Add documentation

* Fix comment

internal/ingress/controller/config/config.go

@@ -467,6 +467,11 @@ type Configuration struct {
 	// server to the client response
 	// Default: empty
 	HideHeaders []string `json:"hide-headers"`
+
+	// LimitReqStatusCode Sets the status code to return in response to rejected requests.
+	// http://nginx.org/en/docs/http/ngx_http_limit_req_module.html#limit_req_status
+	// Default: 503
+	LimitReqStatusCode int `json:"limit-req-status-code"`
 }
 
 // NewDefault returns the default nginx configuration
@@ -560,6 +565,7 @@ func NewDefault() Configuration {
 		JaegerServiceName:            "nginx",
 		JaegerSamplerType:            "const",
 		JaegerSamplerParam:           "1",
+		LimitReqStatusCode:           503,
 	}
 
 	if glog.V(5) {