feat: add trusted proxy identity and overload stats

app/app.go

@@ -21,12 +21,13 @@ import (
 // App is the top-level GoOmni application. Its public behavior depends on
 // httpx.Router, leaving the network implementation replaceable.
 type App struct {
-	router      httpx.Router
-	config      config.Config
-	middlewares []httpx.Middleware
-	closers     []func() error
-	closeOnce   sync.Once
-	closeErr    error
+	router           httpx.Router
+	config           config.Config
+	middlewares      []httpx.Middleware
+	closers          []func() error
+	closeOnce        sync.Once
+	closeErr         error
+	clientIPResolver *httpx.ClientIPResolver
 }
 
 // Runner is the small lifecycle boundary used by an HTTP server
@@ -63,12 +64,17 @@ func configure(options ...config.Option) config.Config {
 }
 
 func newApp(router httpx.Router, settings config.Config) *App {
+	settings.TrustedProxies = append([]string(nil), settings.TrustedProxies...)
+	resolver, err := httpx.NewClientIPResolver(settings.TrustedProxies...)
+	if err != nil {
+		panic("go-omni: " + err.Error())
+	}
 	middlewares := []httpx.Middleware{middleware.RequestID(settings.RequestIDHeader)}
 	if settings.EnableLogger {
 		middlewares = append(middlewares, middleware.AccessLog())
 	}
 	middlewares = append(middlewares, middleware.Recovery())
-	return &App{router: router, config: settings, middlewares: middlewares}
+	return &App{router: router, config: settings, middlewares: middlewares, clientIPResolver: resolver}
 }
 
 // Router returns the transport contract used by this application.
@@ -84,7 +90,11 @@ func (a *App) ServeHTTP(writer http.ResponseWriter, request *http.Request) {
 }
 
 // Config returns the effective application configuration.
-func (a *App) Config() config.Config { return a.config }
+func (a *App) Config() config.Config {
+	settings := a.config
+	settings.TrustedProxies = append([]string(nil), settings.TrustedProxies...)
+	return settings
+}
 
 // Use adds middleware to routes registered after this call.
 func (a *App) Use(middleware ...httpx.Middleware) *App {

app/router.go

@@ -21,6 +21,9 @@ func (a *App) adapt(handler httpx.Handler, middleware ...httpx.Middleware) http.
 		}
 	}
 	return http.HandlerFunc(func(writer http.ResponseWriter, request *http.Request) {
+		if len(a.config.TrustedProxies) > 0 {
+			request = request.WithContext(httpx.WithClientIPResolver(request.Context(), a.clientIPResolver))
+		}
 		requestContext := httpx.NewContext(request, writer, httpx.RouteParams(request.Context()))
 		if err := wrapped(requestContext); err != nil {
 			a.writeError(requestContext, err)