Refactor web UI server setup in main.go and update default host in config

cmd/yggdrasil/main.go

@@ -264,23 +264,6 @@ func main() {
 		}
 	}
 
-	// Set up the web UI server if enabled in config.
-	if cfg.WebUI.Enable {
-		var listenAddr string
-		if cfg.WebUI.Host == "" {
-			listenAddr = fmt.Sprintf(":%d", cfg.WebUI.Port)
-		} else {
-			listenAddr = fmt.Sprintf("%s:%d", cfg.WebUI.Host, cfg.WebUI.Port)
-		}
-
-		n.webui = webui.Server(listenAddr, logger)
-		go func() {
-			if err := n.webui.Start(); err != nil {
-				logger.Errorf("WebUI server error: %v", err)
-			}
-		}()
-	}
-
 	// Set up the multicast module.
 	{
 		options := []multicast.SetupOption{}
@@ -316,6 +299,23 @@ func main() {
 		}
 	}
 
+	// Set up the web UI server if enabled in config.
+	if cfg.WebUI.Enable {
+		var listenAddr string
+		if cfg.WebUI.Host == "" {
+			listenAddr = fmt.Sprintf(":%d", cfg.WebUI.Port)
+		} else {
+			listenAddr = fmt.Sprintf("%s:%d", cfg.WebUI.Host, cfg.WebUI.Port)
+		}
+
+		n.webui = webui.Server(listenAddr, logger)
+		go func() {
+			if err := n.webui.Start(); err != nil {
+				logger.Errorf("WebUI server error: %v", err)
+			}
+		}()
+	}
+
 	//Windows service shutdown
 	minwinsvc.SetOnExit(func() {
 		logger.Infof("Shutting down service ...")

src/config/config.go

@@ -96,7 +96,7 @@ func GenerateConfig() *NodeConfig {
 	cfg.WebUI = WebUIConfig{
 		Enable: false,
 		Port:   9000,
-		Host:   "",
+		Host:   "127.0.0.1",
 	}
 	if err := cfg.postprocessConfig(); err != nil {
 		panic(err)

src/webui/README.md

@@ -0,0 +1,108 @@
+# WebUI Module
+
+This module provides a web interface for managing Yggdrasil node through a browser.
+
+## Features
+
+- ✅ HTTP web server with static files
+- ✅ Health check endpoint (`/health`)
+- ✅ Development and production build modes
+- ✅ Automatic binding to Yggdrasil IPv6 address
+- ✅ IPv4 and IPv6 support
+- ✅ Path traversal attack protection
+
+## Configuration
+
+In the Yggdrasil configuration file:
+
+```json
+{
+  "WebUI": {
+    "Enable": true,
+    "Port": 9000,
+    "Host": "",
+    "BindYgg": false
+  }
+}
+```
+
+### Configuration parameters:
+
+- **`Enable`** - enable/disable WebUI
+- **`Port`** - port for web interface (default 9000)
+- **`Host`** - IP address to bind to (empty means all interfaces)
+- **`BindYgg`** - automatically bind to Yggdrasil IPv6 address
+
+## Usage
+
+### Standard mode
+
+```go
+server := webui.Server("127.0.0.1:9000", logger)
+```
+
+### With core access
+
+```go
+server := webui.ServerWithCore("127.0.0.1:9000", logger, coreInstance)
+```
+
+### Automatic Yggdrasil address binding
+
+```go
+server := webui.ServerForYggdrasil(9000, logger, coreInstance)
+// Automatically binds to [yggdrasil_ipv6]:9000
+```
+
+### Starting the server
+
+```go
+go func() {
+    if err := server.Start(); err != nil {
+        logger.Errorf("WebUI server error: %v", err)
+    }
+}()
+
+// To stop
+server.Stop()
+```
+
+## Endpoints
+
+- **`/`** - main page (index.html)
+- **`/health`** - health check (returns "OK")
+- **`/static/*`** - static files (CSS, JS, images)
+
+## Build modes
+
+### Development mode (`-tags debug`)
+- Files loaded from disk from `src/webui/static/`
+- File changes available without rebuild
+
+### Production mode (default)
+- Files embedded in binary
+- Faster loading, smaller deployment size
+
+## Security
+
+- Path traversal attack protection
+- Configured HTTP timeouts
+- Header size limits
+- File MIME type validation
+
+## Testing
+
+The module includes a comprehensive test suite:
+
+```bash
+cd src/webui
+go test -v
+```
+
+Tests cover:
+- Server creation and management
+- HTTP endpoints
+- Static files (dev and prod modes)
+- Error handling
+- Configuration
+- Yggdrasil IPv6 binding 

src/webui/config_test.go

@@ -164,11 +164,11 @@ func TestWebUIConfig_PortRanges(t *testing.T) {
 			if test.shouldWork {
 				// Try to start briefly to see if port is valid
 				go func() {
-					server.Start()
+					_ = server.Start()
 				}()
 
 				// Quick cleanup
-				server.Stop()
+				_ = server.Stop()
 			}
 		})
 	}
@@ -236,9 +236,9 @@ func TestWebUIConfig_Integration(t *testing.T) {
 
 	// Test that server can start with this config
 	go func() {
-		server.Start()
+		_ = server.Start()
 	}()
-	defer server.Stop()
+	defer func() { _ = server.Stop() }()
 
 	// Verify server properties match config
 	if server.listen != listenAddr {

src/webui/endpoints_test.go

@@ -47,7 +47,7 @@ func TestWebUIServer_HealthEndpointDetails(t *testing.T) {
 	})
 	mux.HandleFunc("/health", func(rw http.ResponseWriter, r *http.Request) {
 		rw.WriteHeader(http.StatusOK)
-		rw.Write([]byte("OK"))
+		_, _ = rw.Write([]byte("OK"))
 	})
 
 	server := httptest.NewServer(mux)
@@ -109,7 +109,7 @@ func TestWebUIServer_NonExistentEndpoint(t *testing.T) {
 	})
 	mux.HandleFunc("/health", func(rw http.ResponseWriter, r *http.Request) {
 		rw.WriteHeader(http.StatusOK)
-		rw.Write([]byte("OK"))
+		_, _ = rw.Write([]byte("OK"))
 	})
 
 	server := httptest.NewServer(mux)
@@ -158,7 +158,7 @@ func TestWebUIServer_ContentTypes(t *testing.T) {
 	})
 	mux.HandleFunc("/health", func(rw http.ResponseWriter, r *http.Request) {
 		rw.WriteHeader(http.StatusOK)
-		rw.Write([]byte("OK"))
+		_, _ = rw.Write([]byte("OK"))
 	})
 
 	server := httptest.NewServer(mux)
@@ -188,7 +188,7 @@ func TestWebUIServer_HeaderSecurity(t *testing.T) {
 	})
 	mux.HandleFunc("/health", func(rw http.ResponseWriter, r *http.Request) {
 		rw.WriteHeader(http.StatusOK)
-		rw.Write([]byte("OK"))
+		_, _ = rw.Write([]byte("OK"))
 	})
 
 	server := httptest.NewServer(mux)
@@ -227,7 +227,7 @@ func TestWebUIServer_ConcurrentRequests(t *testing.T) {
 	})
 	mux.HandleFunc("/health", func(rw http.ResponseWriter, r *http.Request) {
 		rw.WriteHeader(http.StatusOK)
-		rw.Write([]byte("OK"))
+		_, _ = rw.Write([]byte("OK"))
 	})
 
 	server := httptest.NewServer(mux)

src/webui/error_handling_test.go

@@ -30,7 +30,7 @@ func TestWebUIServer_InvalidListenAddress(t *testing.T) {
 			// Start should fail for invalid addresses
 			err := server.Start()
 			if err == nil {
-				server.Stop() // Clean up if it somehow started
+				_ = server.Stop() // Clean up if it somehow started
 				t.Errorf("Expected Start() to fail for invalid address %s", addr)
 			}
 		})
@@ -56,7 +56,7 @@ func TestWebUIServer_PortAlreadyInUse(t *testing.T) {
 	// This should fail because port is already in use
 	err = server.Start()
 	if err == nil {
-		server.Stop()
+		_ = server.Stop()
 		t.Error("Expected Start() to fail when port is already in use")
 	}
 }
@@ -126,7 +126,7 @@ func TestWebUIServer_StopTwice(t *testing.T) {
 
 	// Start server
 	go func() {
-		server.Start()
+		_ = server.Start()
 	}()
 
 	time.Sleep(100 * time.Millisecond)
@@ -218,7 +218,7 @@ func TestWebUIServer_ContextCancellation(t *testing.T) {
 
 	// Start server
 	go func() {
-		server.Start()
+		_ = server.Start()
 	}()
 
 	time.Sleep(100 * time.Millisecond)
@@ -255,7 +255,7 @@ func TestWebUIServer_EmptyListenAddress(t *testing.T) {
 	// This might fail when trying to start
 	err := server.Start()
 	if err == nil {
-		server.Stop()
+		_ = server.Stop()
 		t.Log("Note: Server started with empty listen address")
 	} else {
 		t.Logf("Expected behavior: Start() failed with empty address: %v", err)
@@ -308,7 +308,7 @@ func TestWebUIServer_LargeNumberOfRequests(t *testing.T) {
 	})
 	mux.HandleFunc("/health", func(rw http.ResponseWriter, r *http.Request) {
 		rw.WriteHeader(http.StatusOK)
-		rw.Write([]byte("OK"))
+		_, _ = rw.Write([]byte("OK"))
 	})
 
 	server := httptest.NewServer(mux)

src/webui/server.go

@@ -35,7 +35,7 @@ func (w *WebUIServer) Start() error {
 	// Health check endpoint
 	mux.HandleFunc("/health", func(rw http.ResponseWriter, r *http.Request) {
 		rw.WriteHeader(http.StatusOK)
-		rw.Write([]byte("OK"))
+		_, _ = rw.Write([]byte("OK"))
 	})
 
 	w.server = &http.Server{

src/webui/server_prod.go

@@ -58,7 +58,7 @@ func serveFile(rw http.ResponseWriter, r *http.Request, log core.Logger) {
 
 	// Set headers and serve the file
 	rw.Header().Set("Content-Type", contentType)
-	rw.Write(data)
+	_, _ = rw.Write(data)
 
 	log.Debugf("Served file: %s (type: %s)", filePath, contentType)
 }

src/webui/server_test.go

@@ -1,7 +1,6 @@
 package webui
 
 import (
-	"fmt"
 	"io"
 	"net/http"
 	"net/http/httptest"
@@ -23,22 +22,6 @@ func getTestAddress() string {
 	return "127.0.0.1:0" // Let OS assign available port
 }
 
-// Helper function to wait for server to be ready
-func waitForServer(url string, timeout time.Duration) error {
-	client := &http.Client{Timeout: 1 * time.Second}
-	deadline := time.Now().Add(timeout)
-
-	for time.Now().Before(deadline) {
-		resp, err := client.Get(url)
-		if err == nil {
-			resp.Body.Close()
-			return nil
-		}
-		time.Sleep(50 * time.Millisecond)
-	}
-	return fmt.Errorf("server not ready within timeout")
-}
-
 func TestWebUIServer_Creation(t *testing.T) {
 	logger := createTestLogger()
 	listen := getTestAddress()
@@ -123,7 +106,7 @@ func TestWebUIServer_HealthEndpoint(t *testing.T) {
 	})
 	mux.HandleFunc("/health", func(rw http.ResponseWriter, r *http.Request) {
 		rw.WriteHeader(http.StatusOK)
-		rw.Write([]byte("OK"))
+		_, _ = rw.Write([]byte("OK"))
 	})
 
 	server := httptest.NewServer(mux)
@@ -156,9 +139,9 @@ func TestWebUIServer_Timeouts(t *testing.T) {
 
 	// Start server
 	go func() {
-		server.Start()
+		_ = server.Start()
 	}()
-	defer server.Stop()
+	defer func() { _ = server.Stop() }()
 
 	// Wait for server to start
 	time.Sleep(200 * time.Millisecond)