add bind feature

README.md

@@ -157,6 +157,9 @@ Server:
  GatewayAddress: localhost
  # port to listen on (change to 80 or equivalent if not using TLS)
  Port: 443
+ # local address to bind both the gateway and automatic TLS challenge listeners.
+ # Empty binds to all interfaces. IPv4 and IPv6 addresses are supported.
+ # BindAddress: 127.0.0.1
  # list of acceptable desktop hosts to connect to
  Hosts:
   - localhost:3389

cmd/rdpgw/config/configuration.go

@@ -82,6 +82,7 @@ type Configuration struct {
 type ServerConfig struct {
 	GatewayAddress       string   `koanf:"gatewayaddress"`
 	Port                 int      `koanf:"port"`
+	BindAddress          string   `koanf:"bindaddress"`
 	CertFile             string   `koanf:"certfile"`
 	KeyFile              string   `koanf:"keyfile"`
 	Hosts                []string `koanf:"hosts"`
@@ -215,6 +216,7 @@ func Load(configFile string) Configuration {
 	k.Load(confmap.Provider(map[string]interface{}{
 		"Server.Tls":                 "auto",
 		"Server.Port":                443,
+		"Server.BindAddress":         "",
 		"Server.SessionStore":        "cookie",
 		"Server.HostSelection":       "roundrobin",
 		"Server.Authentication":      "openid",

cmd/rdpgw/main.go

@@ -5,6 +5,7 @@ import (
 	"crypto/tls"
 	"fmt"
 	"log"
+	"net"
 	"net/http"
 	"net/url"
 	"os"
@@ -37,6 +38,10 @@ var opts struct {
 
 var conf config.Configuration
 
+func listenAddress(bindAddress string, port int) string {
+	return net.JoinHostPort(bindAddress, strconv.Itoa(port))
+}
+
 func initOIDC(callbackUrl *url.URL) *web.OIDC {
 	// set oidc config
 	provider, err := oidc.NewProvider(context.Background(), conf.OpenId.ProviderUrl)
@@ -177,7 +182,7 @@ func main() {
 			cfg.GetCertificate = certMgr.GetCertificate
 
 			go func() {
-				http.ListenAndServe(":80", certMgr.HTTPHandler(nil))
+				http.ListenAndServe(listenAddress(conf.Server.BindAddress, 80), certMgr.HTTPHandler(nil))
 			}()
 		}
 	}
@@ -326,7 +331,7 @@ func main() {
 
 	// setup server
 	server := http.Server{
-		Addr:         ":" + strconv.Itoa(conf.Server.Port),
+		Addr:         listenAddress(conf.Server.BindAddress, conf.Server.Port),
 		Handler:      r,
 		TLSConfig:    cfg,
 		TLSNextProto: make(map[string]func(*http.Server, *tls.Conn, http.Handler)), // disable http2

cmd/rdpgw/main_test.go

@@ -0,0 +1,24 @@
+package main
+
+import "testing"
+
+func TestListenAddress(t *testing.T) {
+	tests := []struct {
+		name        string
+		bindAddress string
+		port        int
+		want        string
+	}{
+		{name: "all interfaces", port: 443, want: ":443"},
+		{name: "IPv4", bindAddress: "127.0.0.1", port: 443, want: "127.0.0.1:443"},
+		{name: "IPv6", bindAddress: "::1", port: 443, want: "[::1]:443"},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			if got := listenAddress(test.bindAddress, test.port); got != test.want {
+				t.Fatalf("listenAddress(%q, %d) = %q, want %q", test.bindAddress, test.port, got, test.want)
+			}
+		})
+	}
+}

dev/docker/rdpgw.yaml

@@ -3,6 +3,10 @@ Server:
  KeyFile: /opt/rdpgw/key.pem
  GatewayAddress: localhost:9443
  Port: 9443
+ # BindAddress: ""           # Binds to all interfaces (default)
+ # BindAddress: "127.0.0.1"  # Localhost only (IPv4)
+ # BindAddress: "::1"        # Localhost only (IPv6)
+ # BindAddress: "192.168.1.10"  # Specific IP
  Hosts:
   - xrdp:3389
  RoundRobin: false