feat: add ability to provide interface list to advertise through zeroconf (#164)

* add ability to provide interface list to advertise throw zeroconf

* 1. rename advertise parameter interfaces_to_advertise -> zeroconf_interfaces_to_advertise
2. add some documentation about new parameter

* docs: Fix typo

* docs:  fix typo

Author: tantra35

README.md

@@ -79,6 +79,8 @@ credentials:
 If `persist_credentials` is `true`, after connecting to the device for the first time credentials will be stored locally
 and you can switch to interactive mode without having to authenticate manually.
 
+If `zeroconf_interfaces_to_advertise` is provided, you can limit interfaces that will be advertised. For example, if you have Docker installed on your host, you may want to disable advertising to its bridge interface, or you may want to disable interfaces that will not be reachable.
+
 ### Interactive mode
 
 This mode allows you to associate your account with the device and make it discoverable even outside the network. It

cmd/daemon/main.go

@@ -6,7 +6,6 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	librespot "github.com/devgianlu/go-librespot"
 	"math"
 	"net/http"
 	"os"
@@ -15,6 +14,8 @@ import (
 	"sync"
 	"time"
 
+	librespot "github.com/devgianlu/go-librespot"
+
 	"github.com/devgianlu/go-librespot/apresolve"
 	"github.com/devgianlu/go-librespot/player"
 	devicespb "github.com/devgianlu/go-librespot/proto/spotify/connectstate/devices"
@@ -234,7 +235,7 @@ func (app *App) withAppPlayer(ctx context.Context, appPlayerFunc func(context.Co
 	}
 
 	// start zeroconf server and dispatch
-	z, err := zeroconf.NewZeroconf(app.log, app.cfg.ZeroconfPort, app.cfg.DeviceName, app.deviceId, app.deviceType)
+	z, err := zeroconf.NewZeroconf(app.log, app.cfg.ZeroconfPort, app.cfg.DeviceName, app.deviceId, app.deviceType, app.cfg.ZeroconfInterfacesToAdvertise)
 	if err != nil {
 		return fmt.Errorf("failed initializing zeroconf: %w", err)
 	}
@@ -361,29 +362,30 @@ type Config struct {
 	// finalizer will run, probably closing the lock.
 	configLock *flock.Flock
 
-	LogLevel              log.Level `koanf:"log_level"`
-	DeviceId              string    `koanf:"device_id"`
-	DeviceName            string    `koanf:"device_name"`
-	DeviceType            string    `koanf:"device_type"`
-	ClientToken           string    `koanf:"client_token"`
-	AudioBackend          string    `koanf:"audio_backend"`
-	AudioDevice           string    `koanf:"audio_device"`
-	MixerDevice           string    `koanf:"mixer_device"`
-	MixerControlName      string    `koanf:"mixer_control_name"`
-	AudioBufferTime       int       `koanf:"audio_buffer_time"`
-	AudioPeriodCount      int       `koanf:"audio_period_count"`
-	AudioOutputPipe       string    `koanf:"audio_output_pipe"`
-	AudioOutputPipeFormat string    `koanf:"audio_output_pipe_format"`
-	Bitrate               int       `koanf:"bitrate"`
-	VolumeSteps           uint32    `koanf:"volume_steps"`
-	InitialVolume         uint32    `koanf:"initial_volume"`
-	NormalisationDisabled bool      `koanf:"normalisation_disabled"`
-	NormalisationPregain  float32   `koanf:"normalisation_pregain"`
-	ExternalVolume        bool      `koanf:"external_volume"`
-	ZeroconfEnabled       bool      `koanf:"zeroconf_enabled"`
-	ZeroconfPort          int       `koanf:"zeroconf_port"`
-	DisableAutoplay       bool      `koanf:"disable_autoplay"`
-	Server                struct {
+	LogLevel                      log.Level `koanf:"log_level"`
+	DeviceId                      string    `koanf:"device_id"`
+	DeviceName                    string    `koanf:"device_name"`
+	DeviceType                    string    `koanf:"device_type"`
+	ClientToken                   string    `koanf:"client_token"`
+	AudioBackend                  string    `koanf:"audio_backend"`
+	AudioDevice                   string    `koanf:"audio_device"`
+	MixerDevice                   string    `koanf:"mixer_device"`
+	MixerControlName              string    `koanf:"mixer_control_name"`
+	AudioBufferTime               int       `koanf:"audio_buffer_time"`
+	AudioPeriodCount              int       `koanf:"audio_period_count"`
+	AudioOutputPipe               string    `koanf:"audio_output_pipe"`
+	AudioOutputPipeFormat         string    `koanf:"audio_output_pipe_format"`
+	Bitrate                       int       `koanf:"bitrate"`
+	VolumeSteps                   uint32    `koanf:"volume_steps"`
+	InitialVolume                 uint32    `koanf:"initial_volume"`
+	NormalisationDisabled         bool      `koanf:"normalisation_disabled"`
+	NormalisationPregain          float32   `koanf:"normalisation_pregain"`
+	ExternalVolume                bool      `koanf:"external_volume"`
+	ZeroconfEnabled               bool      `koanf:"zeroconf_enabled"`
+	ZeroconfPort                  int       `koanf:"zeroconf_port"`
+	DisableAutoplay               bool      `koanf:"disable_autoplay"`
+	ZeroconfInterfacesToAdvertise []string  `koanf:"zeroconf_interfaces_to_advertise"`
+	Server                        struct {
 		Enabled     bool   `koanf:"enabled"`
 		Address     string `koanf:"address"`
 		Port        int    `koanf:"port"`

config_schema.json

@@ -155,6 +155,11 @@
           "description": "The port to use for the Zeroconf service (empty for random)",
           "default": 0
         },
+        "zeroconf_interfaces_to_advertise": {
+          "type": "array",
+          "description": "List of network interfaces that will be advertised through zeroconf (empty to advertise all present interfaces)",
+          "default": []
+        },
         "credentials": {
           "type": "object",
           "properties": {

zeroconf/zeroconf.go

@@ -46,7 +46,7 @@ type NewUserRequest struct {
 	result chan bool
 }
 
-func NewZeroconf(log librespot.Logger, port int, deviceName, deviceId string, deviceType devicespb.DeviceType) (_ *Zeroconf, err error) {
+func NewZeroconf(log librespot.Logger, port int, deviceName, deviceId string, deviceType devicespb.DeviceType, interfacesToAdvertise []string) (_ *Zeroconf, err error) {
 	z := &Zeroconf{log: log, deviceId: deviceId, deviceName: deviceName, deviceType: deviceType}
 	z.reqsChan = make(chan NewUserRequest)
 
@@ -63,7 +63,18 @@ func NewZeroconf(log librespot.Logger, port int, deviceName, deviceId string, de
 	listenPort := z.listener.Addr().(*net.TCPAddr).Port
 	log.Infof("zeroconf server listening on port %d", listenPort)
 
-	z.server, err = zeroconf.Register(deviceName, "_spotify-connect._tcp", "local.", listenPort, []string{"CPath=/", "VERSION=1.0", "Stack=SP"}, nil)
+	var ifaces []net.Interface
+	for _, ifaceName := range interfacesToAdvertise {
+		liface, err := net.InterfaceByName(ifaceName)
+		if err != nil {
+			return nil, fmt.Errorf("failed to get info for network interface %s: %w", ifaceName, err)
+		}
+
+		ifaces = append(ifaces, *liface)
+		log.Info(fmt.Sprintf("advertising on network interface %s", ifaceName))
+	}
+
+	z.server, err = zeroconf.Register(deviceName, "_spotify-connect._tcp", "local.", listenPort, []string{"CPath=/", "VERSION=1.0", "Stack=SP"}, ifaces)
 	if err != nil {
 		return nil, fmt.Errorf("failed registering zeroconf server: %w", err)
 	}