added some http-to-kafka docs

_examples/http-to-kafka/main.go

@@ -76,7 +76,7 @@ func main() {
 				return nil, errors.New("empty object kind")
 			}
 
-			// just forward from http subscribert to kafka publisher
+			// just forward from http subscriber to kafka publisher
 			return []*message.Message{msg}, nil
 		},
 	)
@@ -85,8 +85,9 @@ func main() {
 	}
 
 	go func() {
+		// HTTP server needs to be started after router is ready.
 		<-r.Running()
-		httpSubscriber.RunHTTPServer()
+		httpSubscriber.StartHTTPServer()
 	}()
 
 	r.Run()

message/infrastructure/http/subscriber.go

@@ -80,7 +80,9 @@ func (s *Subscriber) Subscribe(topic string) (chan *message.Message, error) {
 	return messages, nil
 }
 
-func (s *Subscriber) RunHTTPServer() error {
+// StartHTTPServer starts http server.
+// StartHTTPServer must be called after all subscribe function are called.
+func (s *Subscriber) StartHTTPServer() error {
 	return s.server.ListenAndServe()
 }