Add custom http listener support

pkg/srv/http.go

@@ -37,6 +37,7 @@ type HTTPServerOpts struct {
 	HandleFuncs      []HTTPFunc
 	Middleware       []http.Handler
 	HealthCheckFuncs []HealthCheckFunc
+	CustomListener   net.Listener
 }
 
 func prepHTTPServer(opts *HTTPServerOpts) *http.Server {
@@ -155,16 +156,26 @@ func InitHTTPServer(opts *HTTPServerOpts) (
 	server = prepHTTPServer(opts)
 
 	go func() {
-		l.Debug().Msg("HTTP Server Started")
-		err := server.ListenAndServe()
+		var err error
+
+		if opts.CustomListener != nil {
+			err = server.Serve(opts.CustomListener)
+		} else {
+			err = server.ListenAndServe()
+		}
+
 		if err != nil && err != http.ErrServerClosed {
 			l.Err(err).Msg("HTTP server error")
 		} else {
 			l.Info().Msg("HTTP server shut down")
 		}
+
+		// Notify app initiator
 		doneChan <- nil
 	}()
 
+	l.Debug().Msg("HTTP Server Started")
+
 	// Shut down http server with a deadline
 	return func(shutdownCtx context.Context) error {
 		l.Debug().Msg("stopping http server")