feat: abstract Zeroconf discovery backend

Author: devgianlu

cmd/daemon/main.go

@@ -253,7 +253,8 @@ func (app *App) withAppPlayer(ctx context.Context, appPlayerFunc func(context.Co
 		DeviceId:   app.deviceId,
 		DeviceType: app.deviceType,
 
-		InterfacesToAdvertise: app.cfg.ZeroconfInterfacesToAdvertise,
+		DiscoveryImplementation: app.cfg.ZeroconfImplementation,
+		InterfacesToAdvertise:   app.cfg.ZeroconfInterfacesToAdvertise,
 	})
 	if err != nil {
 		return fmt.Errorf("failed initializing zeroconf: %w", err)
@@ -409,6 +410,7 @@ type Config struct {
 	ZeroconfEnabled               bool      `koanf:"zeroconf_enabled"`
 	ZeroconfPort                  int       `koanf:"zeroconf_port"`
 	DisableAutoplay               bool      `koanf:"disable_autoplay"`
+	ZeroconfImplementation        string    `koanf:"zeroconf_implementation"`
 	ZeroconfInterfacesToAdvertise []string  `koanf:"zeroconf_interfaces_to_advertise"`
 	MprisEnabled                  bool      `koanf:"mpris_enabled"`
 	Server                        struct {

config_schema.json

@@ -165,6 +165,14 @@
           "description": "List of network interfaces that will be advertised through zeroconf (empty to advertise all present interfaces)",
           "default": []
         },
+        "zeroconf_implementation": {
+          "type": "string",
+          "description": "The Zeroconf implementation to use",
+          "enum": [
+            "builtin"
+          ],
+          "default": "builtin"
+        },
         "credentials": {
           "type": "object",
           "properties": {

zeroconf/discovery/builtin.go

@@ -0,0 +1,29 @@
+package discovery
+
+import (
+	"net"
+
+	"github.com/grandcat/zeroconf"
+)
+
+func init() {
+	discoveryServices["builtin"] = &builtinDiscoveryService{}
+}
+
+type builtinDiscoveryService struct {
+	server *zeroconf.Server
+}
+
+func (s *builtinDiscoveryService) Register(name, service, domain string, port int, txt []string, ifaces []net.Interface) (err error) {
+	s.server, err = zeroconf.Register(name, service, domain, port, txt, ifaces)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func (s *builtinDiscoveryService) Shutdown() {
+	if s.server != nil {
+		s.server.Shutdown()
+	}
+}

zeroconf/discovery/impl.go

@@ -0,0 +1,14 @@
+package discovery
+
+import "net"
+
+type Service interface {
+	Register(name, service, domain string, port int, txt []string, ifaces []net.Interface) error
+	Shutdown()
+}
+
+var discoveryServices = map[string]Service{}
+
+func GetService(name string) Service {
+	return discoveryServices[name]
+}

zeroconf/zeroconf.go

@@ -16,7 +16,7 @@ import (
 	librespot "github.com/devgianlu/go-librespot"
 	"github.com/devgianlu/go-librespot/dh"
 	devicespb "github.com/devgianlu/go-librespot/proto/spotify/connectstate/devices"
-	"github.com/grandcat/zeroconf"
+	"github.com/devgianlu/go-librespot/zeroconf/discovery"
 	log "github.com/sirupsen/logrus"
 )
 
@@ -27,8 +27,8 @@ type Zeroconf struct {
 	deviceId   string
 	deviceType devicespb.DeviceType
 
-	listener net.Listener
-	server   *zeroconf.Server
+	listener  net.Listener
+	discovery discovery.Service
 
 	dh *dh.DiffieHellman
 
@@ -88,9 +88,18 @@ func NewZeroconf(opts Options) (_ *Zeroconf, err error) {
 		log.Info(fmt.Sprintf("advertising on network interface %s", ifaceName))
 	}
 
-	z.server, err = zeroconf.Register(z.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)
+	discoveryImpl := opts.DiscoveryImplementation
+	if discoveryImpl == "" {
+		discoveryImpl = "builtin"
+	}
+
+	z.discovery = discovery.GetService(discoveryImpl)
+	if z.discovery == nil {
+		return nil, fmt.Errorf("unknown discovery implementation: %s", discoveryImpl)
+	}
+
+	if err := z.discovery.Register(z.deviceName, "_spotify-connect._tcp", "local.", listenPort, []string{"CPath=/", "VERSION=1.0", "Stack=SP"}, ifaces); err != nil {
+		return nil, fmt.Errorf("failed registering zeroconf service: %w", err)
 	}
 
 	return z, nil
@@ -105,7 +114,7 @@ func (z *Zeroconf) SetCurrentUser(username string) {
 // Close stops the zeroconf responder and HTTP listener,
 // but does not close the last opened session.
 func (z *Zeroconf) Close() {
-	z.server.Shutdown()
+	z.discovery.Shutdown()
 	_ = z.listener.Close()
 }
 
@@ -260,7 +269,7 @@ func (z *Zeroconf) handleAddUser(writer http.ResponseWriter, request *http.Reque
 type HandleNewRequestFunc func(req NewUserRequest) bool
 
 func (z *Zeroconf) Serve(handler HandleNewRequestFunc) error {
-	defer z.server.Shutdown()
+	defer z.discovery.Shutdown()
 
 	mux := http.NewServeMux()
 	mux.HandleFunc("/", func(writer http.ResponseWriter, request *http.Request) {