Refactor mDNS to use an interface

Author: DerAndereAndi

service/hub.go

@@ -76,7 +76,7 @@ type connectionsHub struct {
 	httpServer *http.Server
 
 	// Handling mDNS related tasks
-	mdns *mdns
+	mdns MdnsService
 
 	// the SPINE local device
 	spineLocalDevice *spine.DeviceLocalImpl
@@ -87,7 +87,7 @@ type connectionsHub struct {
 	muxMdns       sync.Mutex
 }
 
-func newConnectionsHub(serviceProvider serviceProvider, spineLocalDevice *spine.DeviceLocalImpl, configuration *Configuration, localService *ServiceDetails) *connectionsHub {
+func newConnectionsHub(serviceProvider serviceProvider, mdns MdnsService, spineLocalDevice *spine.DeviceLocalImpl, configuration *Configuration, localService *ServiceDetails) *connectionsHub {
 	hub := &connectionsHub{
 		connections:              make(map[string]*ship.ShipConnection),
 		connectionAttemptCounter: make(map[string]int),
@@ -97,7 +97,7 @@ func newConnectionsHub(serviceProvider serviceProvider, spineLocalDevice *spine.
 		spineLocalDevice:         spineLocalDevice,
 		configuration:            configuration,
 		localService:             localService,
-		mdns:                     newMDNS(localService.SKI(), configuration),
+		mdns:                     mdns,
 	}
 
 	return hub
@@ -106,7 +106,7 @@ func newConnectionsHub(serviceProvider serviceProvider, spineLocalDevice *spine.
 // start the ConnectionsHub with all its services
 func (h *connectionsHub) start() {
 	// start mDNS
-	err := h.mdns.Setup()
+	err := h.mdns.SetupMdnsService()
 	if err != nil {
 		logging.Log.Error("error during mdns setup:", err)
 	}
@@ -118,7 +118,7 @@ func (h *connectionsHub) start() {
 		}
 	}()
 
-	if err := h.mdns.Announce(); err != nil {
+	if err := h.mdns.AnnounceMdnsEntry(); err != nil {
 		logging.Log.Error("error registering mDNS Service:", err)
 	}
 }
@@ -168,7 +168,7 @@ func (h *connectionsHub) checkRestartMdnsSearch() {
 	if countPairedServices > countConnections {
 		// if this is not a CEM also start the mDNS announcement
 		if h.localService.deviceType != model.DeviceTypeTypeEnergyManagementSystem {
-			_ = h.mdns.Announce()
+			_ = h.mdns.AnnounceMdnsEntry()
 		}
 
 		logging.Log.Debug("restarting mdns search")
@@ -206,7 +206,7 @@ func (h *connectionsHub) registerConnection(connection *ship.ShipConnection) {
 
 	// shutdown mDNS if this is not a CEM
 	if h.localService.deviceType != model.DeviceTypeTypeEnergyManagementSystem {
-		h.mdns.Unannounce()
+		h.mdns.UnannounceMdnsEntry()
 		h.mdns.UnregisterMdnsSearch(h)
 	}
 }
@@ -228,7 +228,7 @@ func (h *connectionsHub) shutdown() {
 	h.muxCon.Lock()
 	defer h.muxCon.Unlock()
 
-	h.mdns.shutdown()
+	h.mdns.ShutdownMdnsService()
 	for _, c := range h.connections {
 		c.CloseConnection(false, "")
 	}

service/hub_test.go

@@ -5,7 +5,6 @@ import (
 	"time"
 
 	"github.com/enbility/eebus-go/ship"
-	"github.com/enbility/eebus-go/spine/model"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/suite"
 )
@@ -48,13 +47,22 @@ func (s *HubSuite) RemoteSKIConnected(string)          {}
 func (s *HubSuite) RemoteSKIDisconnected(string)       {}
 func (s *HubSuite) ReportServiceShipID(string, string) {}
 
+var _ MdnsService = (*HubSuite)(nil)
+
+func (s *HubSuite) SetupMdnsService() error            { return nil }
+func (s *HubSuite) ShutdownMdnsService()               {}
+func (s *HubSuite) AnnounceMdnsEntry() error           { return nil }
+func (s *HubSuite) UnannounceMdnsEntry()               {}
+func (s *HubSuite) RegisterMdnsSearch(cb MdnsSearch)   {}
+func (s *HubSuite) UnregisterMdnsSearch(cb MdnsSearch) {}
+
 func (s *HubSuite) Test_NewConnectionsHub() {
 	ski := "12af9e"
 	localService := NewServiceDetails(ski)
 	configuration := &Configuration{
 		interfaces: []string{"en0"},
 	}
-	hub := newConnectionsHub(s, nil, configuration, localService)
+	hub := newConnectionsHub(s, s, nil, configuration, localService)
 	assert.NotNil(s.T(), hub)
 
 	hub.start()
@@ -114,10 +122,10 @@ func (s *HubSuite) Test_DisconnectSKI() {
 func (s *HubSuite) Test_RegisterConnection() {
 	ski := "12af9e"
 	localService := NewServiceDetails(ski)
-	localService.SetDeviceType(model.DeviceTypeTypeEnergyManagementSystem) // this won't trigger mDNS announcement
 
 	sut := connectionsHub{
 		connections:  make(map[string]*ship.ShipConnection),
+		mdns:         s,
 		localService: localService,
 	}
 

service/mdns.go

@@ -29,10 +29,21 @@ type MdnsEntry struct {
 	Addresses  []net.IP // mandatory
 }
 
+// implemented by hubConnection, used by mdns
 type MdnsSearch interface {
 	ReportMdnsEntries(entries map[string]MdnsEntry)
 }
 
+// implemented by mdns, used by hubConnection
+type MdnsService interface {
+	SetupMdnsService() error
+	ShutdownMdnsService()
+	AnnounceMdnsEntry() error
+	UnannounceMdnsEntry()
+	RegisterMdnsSearch(cb MdnsSearch)
+	UnregisterMdnsSearch(cb MdnsSearch)
+}
+
 type mdns struct {
 	configuration *Configuration
 	ski           string
@@ -69,14 +80,16 @@ func newMDNS(ski string, configuration *Configuration) *mdns {
 	return m
 }
 
-func (m *mdns) Setup() error {
+var _ MdnsService = (*mdns)(nil)
+
+func (m *mdns) SetupMdnsService() error {
 
 	if av, err := m.setupAvahi(); err == nil {
 		m.av = av
 	}
 
 	// on startup always start mDNS announcement
-	if err := m.Announce(); err != nil {
+	if err := m.AnnounceMdnsEntry(); err != nil {
 		return err
 	}
 
@@ -87,7 +100,7 @@ func (m *mdns) Setup() error {
 
 		<-signalC // wait for signal
 
-		m.Unannounce()
+		m.UnannounceMdnsEntry()
 	}()
 
 	return nil
@@ -141,7 +154,7 @@ func (m *mdns) interfaces() ([]net.Interface, []int32, error) {
 // Announces the service to the network via mDNS
 // A CEM service should always invoke this on startup
 // Any other service should only invoke this whenever it is not connected to a CEM service
-func (m *mdns) Announce() error {
+func (m *mdns) AnnounceMdnsEntry() error {
 	if m.isAnnounced {
 		return nil
 	}
@@ -214,7 +227,7 @@ func (m *mdns) Announce() error {
 }
 
 // Stop the mDNS announcement on the network
-func (m *mdns) Unannounce() {
+func (m *mdns) UnannounceMdnsEntry() {
 	if !m.isAnnounced {
 		return
 	}
@@ -233,8 +246,8 @@ func (m *mdns) Unannounce() {
 }
 
 // Shutdown all of mDNS
-func (m *mdns) shutdown() {
-	m.Unannounce()
+func (m *mdns) ShutdownMdnsService() {
+	m.UnannounceMdnsEntry()
 
 	if m.av != nil {
 		m.av.Close()

service/service.go

@@ -152,8 +152,11 @@ func (s *EEBUSService) Setup() error {
 	entity := spine.NewEntityLocalImpl(s.spineLocalDevice, entityType, entityAddress)
 	s.spineLocalDevice.AddEntity(entity)
 
+	// setup mDNS
+	mdns := newMDNS(s.LocalService.SKI(), s.Configuration)
+
 	// Setup connections hub with mDNS and websocket connection handling
-	s.connectionsHub = newConnectionsHub(s, s.spineLocalDevice, s.Configuration, s.LocalService)
+	s.connectionsHub = newConnectionsHub(s, mdns, s.spineLocalDevice, s.Configuration, s.LocalService)
 
 	return nil
 }