feat(docker): support XUI_PORT runtime override (#5240)

* feat(docker): support XUI_PORT runtime override

Allow deployments to select the panel listener port without mutating the persisted webPort setting. Invalid values fall back to the database-backed port and are covered by parser boundary tests.

* docs: describe XUI_PORT deployment usage

Add commented local and Compose examples, explain runtime precedence, and call out matching Docker bridge port mappings.

internal/config/config.go

@@ -9,6 +9,7 @@ import (
 	"os"
 	"path/filepath"
 	"runtime"
+	"strconv"
 	"strings"
 	"testing"
 )
@@ -63,6 +64,23 @@ func IsSkipHSTS() bool {
 	return os.Getenv("XUI_SKIP_HSTS") == "true"
 }
 
+func GetPortOverride() (port int, configured bool, err error) {
+	value, ok := os.LookupEnv("XUI_PORT")
+	if !ok || strings.TrimSpace(value) == "" {
+		return 0, false, nil
+	}
+
+	port, err = strconv.Atoi(strings.TrimSpace(value))
+	if err != nil {
+		return 0, true, fmt.Errorf("parse XUI_PORT: %w", err)
+	}
+	if port < 1 || port > 65535 {
+		return 0, true, fmt.Errorf("XUI_PORT must be between 1 and 65535")
+	}
+
+	return port, true, nil
+}
+
 // GetBinFolderPath returns the path to the binary folder, defaulting to "bin" if not set via XUI_BIN_FOLDER.
 func GetBinFolderPath() string {
 	binFolderPath := os.Getenv("XUI_BIN_FOLDER")

internal/config/config_test.go

@@ -0,0 +1,61 @@
+package config
+
+import (
+	"os"
+	"testing"
+)
+
+func TestGetPortOverride(t *testing.T) {
+	tests := []struct {
+		name       string
+		value      string
+		set        bool
+		wantPort   int
+		configured bool
+		wantErr    bool
+	}{
+		{name: "unset"},
+		{name: "empty", value: "", set: true},
+		{name: "whitespace", value: "   ", set: true},
+		{name: "minimum", value: "1", set: true, wantPort: 1, configured: true},
+		{name: "default panel port", value: "2053", set: true, wantPort: 2053, configured: true},
+		{name: "surrounding whitespace", value: " 8080 ", set: true, wantPort: 8080, configured: true},
+		{name: "maximum", value: "65535", set: true, wantPort: 65535, configured: true},
+		{name: "zero", value: "0", set: true, configured: true, wantErr: true},
+		{name: "above maximum", value: "65536", set: true, configured: true, wantErr: true},
+		{name: "negative", value: "-1", set: true, configured: true, wantErr: true},
+		{name: "non-numeric", value: "abc", set: true, configured: true, wantErr: true},
+		{name: "decimal", value: "8080.0", set: true, configured: true, wantErr: true},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if tt.set {
+				t.Setenv("XUI_PORT", tt.value)
+			} else {
+				original, existed := os.LookupEnv("XUI_PORT")
+				if err := os.Unsetenv("XUI_PORT"); err != nil {
+					t.Fatalf("unset XUI_PORT: %v", err)
+				}
+				t.Cleanup(func() {
+					if existed {
+						_ = os.Setenv("XUI_PORT", original)
+					} else {
+						_ = os.Unsetenv("XUI_PORT")
+					}
+				})
+			}
+
+			port, configured, err := GetPortOverride()
+			if port != tt.wantPort {
+				t.Errorf("port = %d, want %d", port, tt.wantPort)
+			}
+			if configured != tt.configured {
+				t.Errorf("configured = %t, want %t", configured, tt.configured)
+			}
+			if (err != nil) != tt.wantErr {
+				t.Errorf("error = %v, wantErr %t", err, tt.wantErr)
+			}
+		})
+	}
+}

internal/web/web.go

@@ -407,6 +407,14 @@ func (s *Server) start(restartXray bool, startTgBot bool) (err error) {
 	if err != nil {
 		return err
 	}
+	if envPort, configured, envErr := config.GetPortOverride(); configured {
+		if envErr != nil {
+			logger.Warning("Ignoring invalid XUI_PORT; using configured web port:", port, envErr)
+		} else {
+			port = envPort
+			logger.Info("Using XUI_PORT override for web panel port:", port)
+		}
+	}
 	listenAddr := net.JoinHostPort(listen, strconv.Itoa(port))
 	listener, err := net.Listen("tcp", listenAddr)
 	if err != nil {